Hybrid Integrated Photonics Group

Team Research Publications Teaching News Sponsors Openings Photos

The Hybrid Integrated Photonics Sensors Lab is engaged in state-of-the-art research integrating hybrid materials with large scale silicon photonics circuits for novel applications in computing, communications and chem-bio sensing/ spectroscopy. In sensing and spectroscopy, our research aims to achieve low-cost sensors for environmental pollution monitoring and healthcare diagnostics. In computing, our research aims to achieve energy-efficient switches and modulators with hybrid materials. Devices studied in our group can also have potential applications in quantum photonic computing.

Team Top of Page

Principal Investigator

Swapnajit Chakravarty, Ph.D.,

Dr. Swapnajit Chakravarty obtained his PhD in Electrical Engineering, specializing in optoelectronics and nanophotonics from the University of Michigan, Ann Arbor in 2007. He obtained his B.E. degree in Electrical Engineering in 2001 from Jadavpur University, Kolkata, India, and his M.S. in Electrical Engineering (Electronic Materials and Devices) from the University of Cincinnati in 2003. Prior to joining the University of Dayton, Dr. Chakravarty held a Principal Research Scientist position at IMEC-USA.

Dr. Chakravarty has been an active researcher in integrated nanophotonic devices. His research has covered various nanophotonic lasers, light emitters, chem-bio sensors, on-chip spectrometers on silicon photonics, lithium niobate and III-V material platforms and hybrids. Currently, he investigates hybrid integration of advanced materials for applications in computing, communications and chem-bio sensing /spectroscopy. Dr. Chakravarty has nearly 150 publications in refereed journals and conferences. Dr. Chakravarty holds 12 issued and pending patents on various aspects of nanophotonic sensing. Dr. Chakravarty is a Senior Member of IEEE, SPIE and Optica.

Graduate Students

Jianhao Shen	Jianhao is a fourth-year PhD candidate in Electro-Optics and Photonics. He received his MS in EOP in 2022 from the University of Dayton. Jianhao has a BS from Huazhong University of Science and Technology (HUST) in Electro-Optics in 2020.
Asela Perera	Asela is a third-year PhD candidate in Electro-Optics and Photonics. Asela received his MS in Electrial and Computer Engineering from the Sungkyunkwan University in Seoul, South Korea in 2021 and his BS in Physics from University of Colombo, Sri Lanka, in 2019.
Sheilah Mukami Njoka	Sheilah is a second-year MS student in Electro-Optics and Photonics. Sheilah received her BS in Applied Optics and Lasers from Multimedia University of Kenya (MMU), in 2022. Sheilah is the recipient of a prestigious SPIE Optics and Photonics Scholarship in 2025.
Ifeanyi Jude Njoku	Ifeanyi is a second-year PhD candidate in Electro-Optics and Photonics.
Hao-Wen Kan	Hao-Wen is a second-year MS student in Electro-Optics and Photonics. Hao-Wen received his BS in Physics (Optoelectronics Program) in 2024 from National Chung Hsing University (NCHU).

Undergraduate Students

David Weaver	David is a senior undergraduate in Electrical And Computer Engineering at the University of Dayton. He joined our group in Summer 2024 sponsored by the University of Dayton Summer Undergraduate Research Experience (SURE) program. David is currently doing his Honors thesis in our group on novel field effect transistors.
Ryan Whalen	Ryan is a senior undergraduate in Mechanical Engineering at the University of Dayton. Ryan was also part of the National Science Foundation (NSF) Research Experience for Undergrads (REU) program in Summer 2024. Ryan pursues research integrating microfluidics with silicon photonics for sensing applications. Ryan has 2 second-authored publications till date.
Abdul Ndao	Abdul is a junior undergraduate in Electrical and Computer Engineering Technology at the University of Dayton. Abdul started working with us from Spring 2024 doing undergraduate research in ferroelectric materials.
Heidi Fox	Heidi is a senior undergraduate in Electrical And Computer Engineering at the University of Dayton. She is pursuing research on ferroelectric device characterization and field effect transistor characterization.
Phone Min Thant	Phone is a sophomore undergraduate in Electrical And Computer Engineering at the University of Dayton. He joined our group in 2025 and will continue his research this summer as a UD SURE award recipient doing research on amorphous semiconducting oxide transistors for field effect transistors.
Wai Yan Min Oo	Wai is a sophomore undergraduate in Electrical And Computer Engineering at the University of Dayton. He joined our group in 2025 and is working on measurements on field effect transistors.

Past Undergraduate Students

Daniel Donnelly	Danny joined our group as a sophomore undergraduate in Electrical And Computer Engineering at the University of Dayton from Summer 2022 sponsored by the University of Dayton Summer Undergraduate Research Experience (SURE) program. Danny built all the automation around the photonic integrated circuit setup in my research lab. In 2023, Danny delivered an oral presentation at SPIE Defense and Commercial Sensing in Orlando, FL on his research in on-chip FTIR. Danny graduates with Honors from our research group in 2025 and is going on to pursue graduate studies in EE.
Tristan Quach	Tristan is a senior undergraduate in Electrical And Computer Engineering at the University of Dayton. Tristan was also part of the National Science Foundation (NSF) Research Experience for Undergrads (REU) program in Summer 2023. Tristan graduated in 2025 and is going on to pursue graduate studies in EE. Tristan is second author on one journal paper and one conference paper from his research in ferroelectric hysteresis characterizations.
Liam McClimmans	Liam is a senior undergraduate in Electrical And Computer Engineering at the University of Dayton. Liam worked with us in Summer 2023 sponsored by the University of Dayton Summer Undergraduate Research Experience (SURE) program.
Noelle Boltz	Noelle joined our group as a senior undergraduate in Mechanical Engineering at the University of Dayton sponsored by the UD ETHOS R&D program. She is currently pursuing a graduate degree in ME.
Juan Gauna	Juan joined us in Summer 2023 from St. Mary's University in San Antonio, TX sponsored by the National Science Foundation (NSF) Research Experience for Undergrads (REU) program. Juan is currently working on microfluidic devices at a top research institute in San Antonio, TX. The work is rooted in his research sponsored by the NSF REU program.
Zane Perrico	Zane joined us in Summer 2023 from Youngstown State University in Youngstown, OH sponsored by the National Science Foundation (NSF) Research Experience for Undergrads (REU) program.

Research

Low-Cost Chip Integrated Photonic Biosensing
Hybrid Material Integration for Integrated Photonic Computing and Sensing Applications
Large Scale Photonic Integrated Circuits
Silicon Ferrophotonic Non-Volatile Memory
Amorphous Semiconductor Field Effect Transistors

Publications

Journals Conferences Patents Top of Page

Since joining the University of Dayton

1) A. Perera, T. Quach, J. Shen, S.M. Njoka, A. Drees, S. Chakravarty, Silicon Micro-Ring Resonator Integrated Hafnium Zirconium Oxide Ferro-Photonic Non-Volatile Memory, ACS Photonics 12 (8), 4524 (2025)

2) J. Shen, S. Chakravarty, Design of a compact, resonance trimmed atto-joule-per-bit bus-coupled photonic crystal nanobeam switch, Photonics and Nanostructures - Fundamentals and Applications 63, 101346 (2025)

3) J. Shen, D. Donnelly, S. Chakravarty, Experimental Demonstration of a Resolution-Enhanced Loop-Terminated Mach–Zehnder Interferometer Narrow Band Fourier Transform Spectrometer, IEEE/Optica J. Lightwave Technology 43 (1), 246 (2025)

4) J. Shen, A. Perera, A. Rai, M. Kango-Singh, S. Chakravarty, Experimental Comparison of Slow Light and Subwavelength Waveguide Interferometer Sensors, IEEE Sensors J. 24 (20), 32023 (2024)

5) J. Shen, D. Donnelly, S. Chakravarty, Slow Wave Enhanced On-Chip Michelson Interferometer Sensor, Opt. Lett. 48 (22), 5887 (2023)

Prior to joining the University of Dayton
Starred Publications were funded as Principal Investigator (PI)

6) S. Chakravarty, R. Safian, M. Teng, L. Zhuang, Hybrid Materials Integration in Silicon Photonic Integrated Circuits, Journal of Semiconductors 42 (4), 1 (2021)

7) R. Safian, M. Teng, L. Zhuang, S. Chakravarty, Foundry compatible thin film lithium niobate modulator with RF electrodes buried inside silicon oxide layer of the SOI wafer, Opt. Express 28 (18), 25843 (2020)

8) **C-W. Chang, X. Xu, S. Chakravarty, H-C. Huang, L-W. Tu, Q. Y. Chen, H. Dalir, M. A. Krainak, R. T. Chen, Pedestal subwavelength grating metamaterial waveguide ring resonator for ultra-sensitive label-free biosensing, Biosens. Bioelectron. 141, 111396 (2019)

9) **A. Rostamian, S. Chakravarty, J. Guo, C-J. Chung, D. Nguyen, R. T. Chen, Mid-Infrared silicon on sapphire polarization rotator-splitters, IEEE Photon. Tech. Lett. 31 (5), 401 (2019)

10) **C-J. Chung, J. Midkiff, A. Rostamian, J. Guo, R. T. Chen, S. Chakravarty, InP-based Polarization Rotator-Splitter for Mid-infrared Photonic Integration Circuits, AIP Advances 9 (1), 015303, (2019)

11)**Yi Zou, S. Chakravarty, C-J. Chung, X. Xu, R. T. Chen, Mid-infrared silicon photonic waveguides and devices [Invited], Photon. Res. 6, 254-276 (2018)

12)**H. Yan, C. J. Yang; N. Tang, Y. Zou, S. Chakravarty, A. Roth, R. T. Chen, Specific Detection of Antibiotics by Silicon On-chip Photonic Crystal Biosensor Arrays, IEEE Sensors J. 99, 1 (2017).

13)**L. J. Huang, H. Yan, X. Xu, S. Chakravarty, N. M. Tang, H. P. Tian, R. T. Chen, Improving the detection limit for on-chip photonic sensors based on subwavelength grating racetrack resonators, Opt. Exp. 25 (9), 10527 (2017)

14)**C. Liu, Z. Wang, E. W. Li, Z. X. Liang, S. Chakravarty, X. Xu, A. X. Wang, R. T. Chen, D. L. Fan, Electrokinetic Manipulation Integrated Plasmonic Photonic Hybrid Raman Nanosensors with Dually Enhanced Sensitivity, ACS Sensors 2(3), 346 (2017).

15)**H. Yan, L. J. Huang, X. Xu, S. Chakravarty, H. P. Tian, R. T. Chen, Unique surface sensing property and enhanced sensitivity in microring resonator biosensors based on subwavelength grating waveguides, Opt. Exp. 24 (26), 29725 (2016).

16)**H. Yan, X. Xu, C-J. Chung, H. Subbaraman, Z. Y. Pan, S. Chakravarty, R. T. Chen, One-dimensional photonic crystal slot waveguide for silicon-organic hybrid electro-optic modulators, Opt. Lett. 41 (23), 5466 (2016).

17)**S. Chakravarty, X. Chen, N.Tang, W-C. Lai, Y. Zou, H. Yan, R. T. Chen, Review of design principles of 2D photonic crystal microcavity biosensors in silicon and their applications , Frontiers of Optoelectronics 9(2), 206 (2016).

18)**X. Zhang, S. Chakravarty, C.-J. Chung, Z. Pan, H. Yan and R. T. Chen, Ultra-compact and wide-spectrum-range thermo-optic switch based on silicon coupled photonic crystal microcavities, Applied Physics Letters, vol. 107, 21104 (2015).

19)**Y. Zou, S. Chakravarty, P. Wray, R. T. Chen, Mid-Infrared Holey and Slotted Photonic Crystal Waveguides in Silicon-on-Sapphire for Chemical Warfare Simulant Detection, Sensors and Actuators B 221, 1094 (2015).

20)**Y. Zou, S. Chakravarty, R. T. Chen, Mid-Infrared Silicon-on-Sapphire Waveguide Coupled Photonic Crystal Microcavities, Applied Physics Letters, 107, 081109 (2015).

21)**H. Yan, Y. Zou, S. Chakravarty, C-J. Yang, Z. Wang, N. Tang, D. Fan, R. T. Chen, Silicon on-chip bandpass filters for the multiplexing of high sensitivity photonic crystal microcavity biosensors, Appl. Phys. Lett. 106, 121103 (2015).

22)**Z. Wang, H. Yan, S. Chakravarty, H. Subbaraman, X. Xu, D. Fan, A. X. Wang, R.T. Chen, Microfluidic Channels with Ultralow Loss Waveguide Crossings for Various Chip-integrated Photonic Sensors, Optics Lett. 40(7), 1563 (2015)

23)**Y. Zou, S. Chakravarty, P. Wray, R. T. Chen, Experimental Demonstration of Propagation Characteristics of Mid-Infrared Photonic Crystal Waveguides in Silicon-on-Sapphire, Optics Express 23, 6965 (2015).

24)**X. Xu, H. Subbaraman, S. Chakravarty, A. Hosseini, J. Covey, D. Kwong, W-C. Lai, Y. Zou, Y-H. Chen, N. Lu, R.T. Chen, Flexible Single Crystal Silicon Nanomembrane Photonic Crystal Cavity, ACS Nano 8(12), 12265 (2014).

25)**S. Chakravarty, A. Hosseini, X. Xu, L. Zhu, Y. Zou, R. T. Chen, Analysis of ultra-high sensitivity configuration in chip-integrated photonic crystal microcavity bio-sensors, Appl. Phys. Lett. 104, 191109 (2014).

26)**Y. Zou, H. Subbaraman, S. Chakravarty, X. Xu, A. Hosseini, W. Lai, P. Wray, R. T. Chen, Grating-coupled silicon-on-sapphire integrated slot waveguides operating at mid-infrared wavelengths, Optics Lett. 39, 3070-3073 (2014).

27)**Y. Zou, S. Chakravarty, L. Zhu, R. T. Chen, The role of group index engineering in series-connected photonic crystal microcavities for high density sensor microarrays, Appl. Phys. Lett.104, 141103 (2014).

28)D. Kwong, J. Covey, A. Hosseini, X. Xu, Y. Zhang, S. Chakravarty, R. T. Chen, Corrugated Waveguide Based Optical Phased Array with Crosstalk Suppression, IEEE Photon. Tech. Lett. 26 (10), 991 (2014).

29)**Y. Zou, S. Chakravarty, D. N. Kwong, W-C. Lai, X. Xu, X. Lin, A. Hosseini, R. T. Chen, Cavity-Waveguide Coupling Engineered High Sensitivity Silicon Photonic Crystal Microcavity Biosensors with High Yield, IEEE J. Sel. Top. Quant. Electron. 20(4), 6900710 (2014).

30)X. Zhang, A. Hosseini, S. Chakravarty, J. Luo, A. K-Y Jen, R. T Chen, Wide optical spectrum range, subvolt, compact modulator based on an electro-optic polymer refilled silicon slot photonic crystal waveguide, Optics Lett. 38 (22), 4931-4934 (2013)

31)**W-C. Lai, S Chakravarty, Y Zou, RT Chen, Multiplexed detection of xylene and trichloroethylene in water by photonic crystal absorption spectroscopy, Optics Lett. 38 (19), 3799-3802 (2013)

32)**W-C. Lai, S. Chakravarty, Y. Zou, R.T. Chen, Slow Light Enhanced Sensitivity of Resonance Modes in Photonic Crystal Biosensors, Appl. Phys. Lett. 102 (4), 041111 (2013)

33)**S. Chakravarty, W-C. Lai, Y. Zou, H.A. Drabkin, G.R. Simon, S.H. Chin, R. M. Gemmill, R.T. Chen, Multiplexed Specific Label-Free Detection of NCI-H358 Lung Cancer Cell Line Lysates with Silicon Based Photonic Crystal Microcavity Biosensors, Biosens. Bioelectron. 43, 50 (2013).

34)**S. Chakravarty, Y. Zou, W-C. Lai, R.T. Chen, Slow light engineering for high Q high sensitivity photonic crystal microcavity biosensors in silicon, Biosens. .Bioelectron. 38(1), 170 (2012).

35)**Y. Zou, S. Chakravarty, W-C. Lai, R.T. Chen, Methods to Array Photonic Crystal Microcavities for High Throughput High Sensitivity Bio-Sensing on a Silicon-Chip Based Platform, Lab Chip 12, 2309 (2012).

36)*W-C. Lai, S. Chakravarty, Y. Zou, R.T. Chen, Silicon nano-membrane based photonic crystal microcavities for high sensitivity bio-sensing, Optics Lett. 37 (7), 1208 (2012)

37)**X.B. Xu, D.H. Hasan, L. Wang, S. Chakravarty, R.T. Chen, D.L. Fan, A.X. Wang, Guided-mode-resonance-coupled plasmonic-active SiO2 nanotubes for surface enhanced Raman spectroscopy, Appl. Phys. Lett. 100(19), 191114 (2012).

38)C-Y. Lin, X. Wang, W-C. Lai, J.L. Covey, S. Chakravarty, R.T. Chen, Coupling loss minimization of slow light slotted photonic crystal waveguides using mode matching with continuous group index perturbation, Optics Lett. 37, 232 (2012).

39)**W-C. Lai, S. Chakravarty, X. Wang, C. Lin, R.T. Chen, On-Chip methane sensing by near-IR absorption signatures in a photonic crystal slot waveguide, Optics Lett. 36, 984 (2011).

40)**W-C. Lai, S. Chakravarty, X. Wang, C. Lin, R.T. Chen, Photonic Crystal Slot Waveguide Absorption Spectrometer for On-Chip Near-Infrared Spectroscopy of Xylene in Water, Appl. Phys. Lett. 98 (2), 023304 (2011).

41)X. Wang, C-Y. Lin, S. Chakravarty, J. Luo, A-K-Y. Jen, R.T. Chen, Effective In‐Device r33 of 735pm/V on Electrooptic Polymer Infiltrated Silicon Photonic Crystal Slot Waveguide, Optics Lett. 36 (6), 882 (2010).

42)C-Y. Lin, X. Wang, S. Chakravarty, B-S. Lee, W-C. Lai, R.T. Chen, Wideband Group Velocity Independent Coupling into Slow Light Silicon Photonic Crystal Waveguide, Appl. Phys. Lett. 97 (18), 183302 (2010).

43)C-Y. Lin, X. Wang, S. Chakravarty, B-S. Lee, W-C. Lai, J. Luo, A-K-Y. Jen, R.T. Chen, Electro-optic polymer infiltrated silicon photonic crystal slot waveguide modulator with 23 dB slow light enhancement, Appl. Phys. Lett. 97 (9), 093304 (2010).

44)X. Wang, S. Chakravarty, B-S. Lee, C. Lin, R.T. Chen, Ultraefficient control of light transmission through photonic potential barrier modulation, Opt. Lett. 34(20), 3202 (2009).

45)X. Chen, A. Wang, S. Chakravarty, R.T. Chen, Electrooptically-active slow light enhanced silicon slot photonic crystal waveguides, IEEE Journal of Selected Topics in Quantum Electronics 15 (5), 1506 (2009).

46)S. Chakravarty, P. Bhattacharya, S. Chakrabarti, Z. Mi, Multiwavelength ultra-low threshold lasing in quantum dot photonic crystal microcavities, Opt. Lett. 32, 1296 (2007), also selected in the Virtual J. Nanoscale Science and Tech. (Vol. 15, Issue 17, 2007).

47)S. Chakravarty, P.Bhattacharya, Z. Mi, Electrically injected quantum-dot photonic crystal microcavity light emitting arrays with air-bridge contacts, IEEE Photon. Tech. Lett., 18, 2665 (2006).

48)S. Chakravarty, P. Bhattacharya, J. Topolancik, Electrically-injected quantum-dot photonic-crystal microcavity light-emitters and microcavity arrays, J. Phys. D 40, 2683 (2007).

49)P. Boolchand, M. Jin, D. Novita, S. Chakravarty, Raman scattering as a probe of intermediate phases in glassy networks, Journal of Raman Spectroscopy 38 (6), 660 (2007).

50)J. Topolancik, S. Chakravarty, P. Bhattacharya, S. Chakrabarti, Electrically injected quantum-dot photonic crystal microcavity light sources, Opt. Lett.31, 232 (2006), also selected in the Virtual J. Nanoscale Science and Tech. (Vol. 13, Issue 6, 2006)

51)P. Bhattacharya, J. Sabarinathan, J. Topolancik, S. Chakravarty, P.C. Yu, W. Zhou, Quantum dot photonic crystal light sources, Proc. of the IEEE 93 (10), 1825-1838 (2005).

52)S. Chakravarty, J. Topolancik, P. Bhattacharya, S. Chakrabarti, Y. Kang, M.E. Meyerhoff, Ion detection with photonic crystal microcavities, Opt. Lett. 30, 2578 (2005).

53)P. C. Yu, J. Topolancik, S. Chakravarty, P. Bhattacharya, Mode-coupling characteristics and efficiency of quantum-dot electrically injected photonic crystal waveguide-coupled light-emitting diodes, IEEE Journal of Quantum Electronics 41(3), 455 (2005).

54)S. Chakravarty, D.G. Georgiev, P. Boolchand, M. Micoulaut, Aging, fragility and the reversibility window in bulk alloy glasses, J. Phys.-Cond. Matt. 17(1), L1-L7 (2005).

55)P. Boolchand, D.G. Georgiev, T. Qu, F. Wang, L. Cai, and S. Chakravarty, Nano-scale phase separation effects near r = 2.4 and 2.67, and rigidity transitions in chalcogenide glasses, Comptes Rendus Chimie 5 (11), 713-724 (2002).

Conferences Patents Top of Page

Since joining the University of Dayton

1) S.M. Njoka, R. Whalen, J. Shen, I. Njoku, S. Chakravarty, Loop-terminated Mach-Zehnder interferometer for gas sensing on silicon-on-insulator platform, SPIE Optics and Photonics, Paper 13608-13 (2025)

2) S. M, Njoka, R. Whalen, T. Momin, J. Shen, M. Rajput, S. Chakravarty, Packaged silicon-photonic slow-light asymmetric Michelson interferometer (MI) for virus detection, SPIE Optics and Photonics, Paper 13608-3 (2025)

3) J. Shen, S. M. Njoka, S. Chakravarty, Experimental demonstration of fixed wavelength slow light interferometric sensor with phase change material tuning, SPIE Optics and Photonics, Paper 13608-4 (2025)

4) A. Perera, D. K. Saini, D. Donnelly, S. M. Njoka, B. Rout, S. Chakravarty, Radiation effects on waveguide coupled photonic crystal nanocavity devices, SPIE Optics and Photonics, Paper 13628-38 (2025)

5) A. Perera, T. Quach, J. Shen, S. Chakravarty, Hybrid hafnium zirconium oxide integrated silicon photonic microring based non-volatile memory, SPIE Optics and Photonics, Paper 13578-78 (2025)

6) S. Chakravarty, J. Shen, D. Donnelly, Compact Interferometer Devices for Chip-Based Chem-Bio Sensing, SPIE Photonics West 12861-4 (2024) (Invited)

7) J. Shen, J. C. Gauna, A. Rai, L. McClimans, R. Lawandi, A. Perera, M. Kango-Singh, S. Chakravarty, Fixed Wavelength Interferometer Sensors for Low-Cost Chem-Bio Sensing Applications, SPIE Photonics West 12861-8 (2024)

8) A. Perera, J. Shen, S. Chakravarty, Sub-Wavelength Waveguide Michelson Interferometer Sensors, SPIE Photonics West 12861-9 (2024)

9) Z. Perrico, J. Shen, A. Perera, S. Chakravarty, Electrochemical Bubble Delamination and Transfer of CVD Graphene from Copper to Si/SiO2 Utilizing Mechanical Assistance, 2023 Fall Meeting of the APS Eastern Great Lakes Section (10/21/2023); Bulletin of the American Physical Society L05.00001 (2023)

10) D. Donnelly, J. Shen, S. Chakravarty, A compact Michelson Interferometer based on-chip Fourier Transform Spectrometer, SPIE Defense and Commercial Sensing 12516-16 (2023); Proc. of the SPIE 12516, 125160F (2023)

11) J. Shen, D. Donnelly, S. Chakravarty, Reflected path enhanced absorbance in an integrated photonic gas sensor, SPIE Defense and Commercial Sensing 12532-25 (2023); Proc. of the SPIE 12532, 125320R (2023)

12) J. Shen, D. Donnelly, S. Chakravarty, Integrated photonic slow light Michelson interferometer bio sensor, SPIE Photonics West 12424-85 (2023); Proc. of the SPIE 12424, 124241B (2023)

13) J. Shen, D. Donnelly, S. Chakravarty, Compact, oxide-embedded atto-joule-per-bit bus-coupled photonic crystal nanobeam switches, SPIE Photonics West 12424-72 (2023); Proc. of the SPIE 12424, 1242412 (2023)

14) J. Shen, S. Chakravarty, Compact, multiplexed, energy-efficient silicon nanophotonic switches, SPIE International Workshop on Thin Films for Electronics, Electro-Optics, Energy and Sensors 2022, 12477, 1247703 (2023) (Invited)

15) J. Shen, A. Perera, D. Donnelly, S. Chakravarty, Phase-change-material phase error corrected resolution enhanced Michelson interferometer Fourier Transform Spectrometer, Oral Presentation, Control Number: 4030433, SF2A.6 (2024) (Peer-Reviewed)

16) J. Shen, A. Perera, S. Chakravarty, Phase-corrected fixed wavelength slow wave Michelson interferometer chem-bio sensor, Control Number: 4030501, SM4E.3 (2024) (Peer-Reviewed)

Prior to joining the University of Dayton
Starred Publications were funded as Principal Investigator (PI)

17) T. Fan, R. Safian, S. Chakravarty, L. Zhuang, A wideband polarization rotator-splitter based on imec iSiPP50G silicon photonics platform, Proc. Of the SPIE 11691-2 (2021)

18) L. Zhuang, R. Safian, S. Chakravarty, A.N.R. Ahmed, M. Teng, Y. Xie, D. Dai, P. Jiao, M. Ding, C. Zhang, Silicon photonics nonlinear switch as conditional circulator for single-aperture LIDAR systems, Proc. Of the SPIE 11691-18 (2021)

19) S. Chakravarty, R. Safian, L. Zhuang, Wide optical and RF Bandwidth thin film lithium niobate modulator on silicon, CLEO (Opt. Soc. of America, JTu3A.126 (2021)

20) R. Safian, S. Chakravarty, M. Teng, L. Zhuang, Foundry-compatible thin-film lithium niobate electro-optic modulators, Integrated Optics: Devices, Materials, and Technologies XXIV, 11283, 112832F (2020).

21) **J. Midkiff, S. Chakravarty, K-M. Yoo, R. T. Chen, Mid-Infrared 2-D Beam Steering, CLEO (Opt. Soc. of America, Oral Presentation, AW3K.5 (2019)

22) **K-M. Yoo, J. Midkiff, A. Rostamian, S. Chakravarty, R. T. Chen, Suspended Membrane InGaAs Photonic Crystal Waveguides for ammonia sensing at lambda=6.15um, CLEO (Opt. Soc. of America, STh1F. 6 (2019).

23) **S. Chakravarty, R. T. Chen et al., Compact integrated photonic components for lambda=3-15 micron, Proceedings of the SPIE 109210D (2019); (SPIE Photonics West, 2019, (Oral presentation)

24) **J. Midkiff, S. Chakravarty, K. Yoo, A. Rostamian, R. T. Chen, Monolithic integration of quantum cascade laser, quantum cascade detector, and subwavelength waveguides for mid-infrared integrated gas sensing, Proceedings of the SPIE 109261V (2019); SPIE Photonics West, 2019, (Oral presentation)

25) S. Chakravarty, J. Midkiff, K. Yoo, A. Rostamian, R. T. Chen, Chip Integrated Handheld Absorption Spectroscopy, (Invited)** GOMACTech (Government Microcircuit and Critical Technologies) Conference, Albuquerque, New Mexico (March 2019)

26) **J. Guo, A. Rostamian, S. Chakravarty, H. Yan, C-J. Chung, E.Heidari, R.T. Chen, Mid-Infrared Silicon-on-Sapphire Polarization Rotator, CLEO (Opt. Soc. of America, SF3J.6 (2018)

27) **A. Rostamian, J. Guo, S. Chakravarty, C-J. Chung, D. Nguyen, R. T. Chen, Parts-Per-Billion Carbon Monoxide Sensing in Silicon-on-Sapphire Mid-Infrared Photonic Crystal Waveguides, in CLEO (Optical Society of America, ATh1O.4 (2018)

28) **S. Chakravarty, J. Midkiff, A. Rostamian, J. Guo, R. T. Chen, Monolithic Integration of Quantum Cascade Laser, Quantum Cascade Detector and Slotted Photonic Crystal Waveguide for Absorbance Sensing from lambda=3-15um, in CLEO (Optical Society of America, STh1B.4 (2018)

29) **S. Chakravarty, J. Midkiff, C-J. Chung, A. Rostamian, J. Guo, R. T. Chen, Polarization Rotator in Low Index Contrast Substrates for Mid-Infrared Photonic Integration, in CLEO (Optical Society of America, JW2A.40 (2018)

30) S. Chakravarty, X. Xu, H. Yan, -C. Lai, Y. Zou, R. T. Chen, Slow Light Enhanced Silicon Chip Based Chem-Bio Sensors, OSA Adv. Photon. Congress, New Orleans, LA (2017) (Invited)**

31) **S. Chakravarty, H. Yan, Y. Zou, R. T. Chen, Mid-Infrared Silicon Photonic Devices and Sensors, IEEE Photonics Summer Topicals, San Juan, Puerto Rico (2017)

32) **L. J. Huang, H. Yan, X. Xu, S. Chakravarty, N. M. Tang, H. P. Tian, R. T. Chen, Low detection limit sensor based on subwavelength grating racetrack resonator, Proc. of the SPIE 10077, 100770M (2017) doi: 10.1117/12.2252429

33) **Z. Wang, C. Liu, E. W. Li, S. Chakravarty, A. X. Wang, D. L. Fan, R. T. Chen, Models and Raman Analysis of Molecular Nanofilms Conjugated on Photonic Crystal Slabs, Proc. of the SPIE 10077, 10077G (2017) doi: 10.1117/12.2253392

34) **H. Yan, X. Xu, C. J. Chung, H. Subbaraman, Z. Y. Pan, S. Chakravarty, R. T. Chen, One-dimensional photonic crystal slot waveguide for silicon-organic hybrid electro-optic modulators, Proc. of the SPIE 10109, 10109O-1 (2017) doi: 10.1117/12.2253154

35) **Z. Wang, H. Yan, S. Chakravarty, D. Fan, R. T. Chen, Coupled Photonic Crystal Microcavities for High-Q sensing, IEEE CLEO San Jose Jun 5-10, (2016).

36) H. Yan, X. Xu, C-J. Chung, H. Subbaraman, Z. Y. Pan, S. Chakravarty, R. T. Chen, Silicon-organic Hybrid Electro-optic Modulator Based on One-dimensional Photonic Crystal Slot Waveguides, IEEE CLEO San Jose Jun 5-10, (2016).

37) **Y. Zou, S. Chakravarty, C.-J. Chung, R. T. Chen, Miniature mid-infrared thermo-optic switch with photonic crystal waveguide-based silicon-on-sapphire Mach-Zehnder interferometers, in OPTO (Photonics West), San Francisco, California, United States (2016) (oral).

38) **H. Yan, N. Tang, S. Chakravarty, R. T. Chen, High-sensitivity high-throughput chip based biosensor array for multiplexed detection of heavy metals, in BiOS (Photonics West), San Francisco, California, United States (2016) (oral) Proc. of the SPIE 9725, 972507 (2016).

39) **Y. Zou, S. Chakravarty, R. T. Chen, Mid-infrared silicon-on-sapphire waveguide-coupled photonic crystal microcavities, in OPTO (Photonics West), San Francisco, CA (2016) (oral).

40) S. Chakravarty, Ray T. Chen, N. Tang, Y. Zou, W.-C. Lai, H. Yan, C.-J. Yang, Silicon chip integrated photonic sensors for biological and chemical sensing, in BiOS (Photonics West), San Francisco, California, United States, 14th February 2016 (Invited)**. (oral) Proc. of the SPIE 9705, 97250O (2016).

41) **X. Zhang, S. Chakravarty, C.-J. Chung, Z. Pan, H. Yan, and R. T. Chen, Microheater-integrated silicon coupled photonic crystal microcavities for low-power thermo-optic switching over a wide spectrum, in in OPTO (Photonics West), San Francisco, CA (2016) (oral)

42) **Y. Zou, P. Wray, S. Chakravarty, R. T. Chen, Experimental Demonstration of Mid-Infrared Holey and Slotted Photonic Crystal Waveguides in Silicon on Sapphire, in CLEO (Optical Society of America), Abstract ID: STu4I.3, San Jose, CA (2015).

43) **C-J. Yang, N. Tang, H. Yan, S. Chakravarty, D. Li, R. T. Chen, 193nm Lithography Fabricated High Sensitivity Photonic Crystal Microcavity Biosensors for Plasma Protein Detection in Patients with Pancreatic Cancer, in CLEO (OSA), Abstract ID: STu4K.5, San Jose, CA (2015).

44) **X. Xu, H. Subbaraman, S. Chakravarty, and R. T. Chen, Bending Behavior of Flexible Crystalline Silicon Nanomembrane Photonic Crystal Microcavities, in CLEO: 2015, OSA Technical Digest (online) (Optical Society of America, 2015), paper SF2H.3

45) **Y. Zou, P. Wray, S. Chakravarty, R. T. Chen, Silicon on Sapphire Chip Based Photonic Crystal Waveguides for Detection of Chemical Warfare Simulants And Volatile Organic Compound, in CLEO (Optical Society of America), Abstract ID: AF2J.1, San Jose, CA (2015).

46) **Y. Zou, K. Vijayraghavan, P. Wray, S. Chakravarty, M.A. Belkin, R. T. Chen, Monolithically Integrated Quantum Cascade Lasers, Detectors and Dielectric Waveguides at 9.5um for Far-Infrared Lab-on-Chip Chemical Sensing, in CLEO (Optical Society of America), Abstract ID: STu4I.2, San Jose, CA (2015).

47) **Z. Wang, C. Liu, S. Chakravarty, D.L. Fan, A. Wang, R. T. Chen, Universal Enhancement of Raman Scattering Sensing by Plasmonic Nanotubes Coupled with Photonic Crystal Slab, in CLEO (Optical Society of America), Abstract ID: SM3O.3, San Jose, CA (2015).

48) **H. Yan, C-J. Yang, Y. Zou, N. Tang, S. Chakravarty, R. T. Chen, Wide Dynamic Range Specific Detection of Therapeutic Drugs by Photonic Crystal Microcavity Arrays, in CLEO (Optical Society of America), Abstract ID: STu4K.2, San Jose, CA (2015).

49) **X. Zhang, S. Chakravarty, C-J. Chung, Z. Pan, R. T. Chen, Wide-spectrum-range Power-efficient Compact Thermo-optic Switch Based on Coupled Photonic Crystal Microcavities, in CLEO (Optical Society of America), San Jose, CA (2015).

50) **Y. Zou, S. Chakravarty, X. Xu, R.T. Chen, Integrated photonic crystal waveguides on silicon-on-sapphire for chemical sensing in mid-infrared, Proc. SPIE 9367, Silicon Photonics X, 93670X (2015)

51) **S. Chakravarty, N. Tang, H. Yan, C. Yang, Y. Zou, R. Gemmill, Q. Shen, R. T. Chen, Photonic Crystal Microarray Sensing of Cancer Cell Line Lysates, AACR Annual Meeting, 2014:5317. (2014)

52) **Y. Zou, S. Chakravarty, W. Lai, R. T. Chen, Silicon Chip Based Near-Infrared and Mid-Infrared Optical Spectroscopy for Volatile Organic Compound Sensing, in CLEO (Optical Society of America), Abstract ID STh3M.6. San Jose, CA (2014)

53) **C. Yang, Y Zou, S. Chakravarty, H. Yan, Z. Wang, R.T. Chen, Wide Dynamic Range Sensing in Photonic Crystal Microcavity Biosensors, in CLEO (Optical Society of America), Abstract ID STh4H.5. San Jose, CA (2014)

54) **P. Wray, Y. Zou, S. Chakravarty, R. T. Chen, Silicon on Sapphire Chip Based Mid-Infrared Optical Spectroscopy for Detection of Chemical Warfare Simulant Triethyl phosphate, in CLEO (Optical Society of America), Abstract ID AW1P.2. San Jose, CA (2014)

55) **H. Yan, Y. Zou, C. Yang, Z. Wang, N. Tang, S. Chakravarty, R. T. Chen, Photonic Crystal (PC) Waveguide Based Optical Filters for Dense Integration of High Sensitivity PC Biosensors, in CLEO (Optical Society of America), Abstract ID JTu4A.94. San Jose, CA (2014)

56) **X. Xu, H. Subbaraman, A. Hosseini, S. Chakravarty, R. T. Chen, Flexible Crystalline Silicon Nanomembrane Photonic Crystal Microcavity, in CLEO (Optical Society of America), Abstract ID SW1M.6. San Jose, CA (2014)

57) **Z. Wang, S. Chakravarty, H. Subbaraman, X. Xu, D. Fan, A. Wang, R. T. Chen, Micro-fluid Channel Based on Ultralow-loss Silicon Crossing Waveguide for Various Sensing, in CLEO (Optical Society of America), Abstract ID ATu2P.5. San Jose, CA (2014)

58) **X. Xu, H. Subbaraman, S. Chakravarty, R. T. Chen, High-performance conformal sensors employing single-crystal silicon nanomembranes, Proc. SPIE 8990, Silicon Photonics IX, 89900U (March 8, 2014).

59) **S. Chakravarty, H. Subbaraman, Y. Zou, W. Lai, R. T. Chen, Methods to array photonic crystal microcavities for high throughput high sensitivity biosensing on a silicon-chip based platform, Proc. SPIE 8990, Silicon Photonics IX, 89900S (March 8, 2014).

60) **Y. Zou, H. Subbaraman, S. Chakravarty, X. Xu, A. Hosseini, W. Lai, R. T. Chen, Integrated strip and slot waveguides in silicon-on-sapphire for Mid-Infrared VOC detection in Water, Proc. SPIE 8990, Silicon Photonics IX, 89900X (March 8, 2014).

61) **W. Lai, Y. Zou, S. Chakravarty, L. Zhu, R. T. Chen, Comparative sensitivity analysis of integrated optical waveguides for near-infrared volatile organic compounds with 1ppb detection, Proc. SPIE 8990, Silicon Photonics IX, 89900Z (March 8, 2014).

62) S. Chakravarty, W-C. Lai, Y. Zou, R.T. Chen, Silicon Photonic Crystal Open Sensors for High Sensitivity Multiplexed Chem-Bio Sensing, OSA Frontiers in Optics (2013) (Invited)**

63) D. Kwong, J.L. Covey, A. Hosseini, X. Xu, Y. Zhang, S. Chakravarty, R.T. Chen, Crosstalk Suppression of Corrugated Waveguides in an Optical Phased Array Using 2D Photonic Crystal Slab, CLEO, San Jose, CA (2013),

64) **X Zhang, A Hosseini, X Xu, S Wang, Q Zhan, Y Zou, S Chakravarty, RT Chen, Electric field sensor based on electro-optic polymer refilled silicon slot photonic crystal waveguide coupled with bowtie antenna, SPIE Photonics West, San Francisco, CA (2013); Proc. of the SPIE OPTO, 862418-862418-8 (2013) (Citation: 19)

65) **C-C.Hsieh, S. Chakravarty, Y. Zou, L. Zhu, R.T. Chen, High Sensitivity Biosensing Based on Symmetric Coupled Cavity Structure of Photonic Crystal Microcavities, Oral Presentation at CLEO, San Jose, CA (2013); Pres. Number: CM2H.8; Control Number: 1661677.

66) **L. Zhu, S. Chakravarty, C-C. Hsieh, W-C. Lai, R.T. Chen, Slow Light Waveguide and Enhanced Area Microcavity Engineering for High Sensitivity Photonic Crystal Sensors, Poster Presentation at CLEO, San Jose, CA (2013); Pres. Number: JTu4A.103; Control Number: 1662186

67) **Y. Zou, S. Chakravarty, W-C. Lai, R.T. Chen, High yield silicon photonic crystal microcavity biosensors with 100fM detection limit, Oral Presentation at SPIE Photonics West, San Francisco, CA (2013); Proc. of the SPIE 8570, 857008 (2013)

68) S. Chakravarty, R.T. Chen, W-C. Lai, Y. Zou, R.M. Gemmill, Silicon photonic crystal microarrays for high throughput label-free proteomics for detection of cancers with sensitivity and specificity, (Invited)** Oral Presentation at SPIE Photonics West, San Francisco, CA (2013); Proc. of the SPIE 8570, 857005 (2013)

69) **W-C. Lai, S. Chakravarty, Y. Zou, R.T. Chen, Multiplexed selective detection and identification of TCE and xylene in water by on-chip absorption spectroscopy, Oral Presentation at SPIE Photonics West, San Francisco, CA (2013); Proc. of the SPIE 8627, 86270K (2013)

70) J. Ahn, H. Subbaraman, L. Zhu, S. Chakravarty, E. Tutuc, R.T. Chen, 2D silicon-based surface-normal vertical cavity photonic crystal waveguide array for high density optical interconnects, SPIE Photonics West, San Francisco, CA (2013); Proc. of the SPIE 8630, 86300D (2013).

71) **S. Chakravarty, W-C. Lai, Y. Zou, H.A. Drabkin, G.R. Simon, S.H. Chin, R.T. Chen, R. M. Gemmill, Photonic crystal microarray sensing of biomolecules: Detection of ZEB1 associated with the epithelial-mesenchymal transition in lung cancer cells, Abstract 735, Poster Section 31, AACR Annual Meeting, Washington DC, 6-10 April (2013).

72) S. Chakravarty, R.T. Chen, W-C. Lai, Y. Zou, Silicon Photonic Crystal Microcavity Biosensors for Multiplexed High Throughput Detection of Cancers with Specificity and High Sensitivity, (Invited)** Oral Presentation at 10th International Conference on nano-molecular electronics, Awaji Yumebutai International Conference Center, Awaji, Hyogo, Japan, 12-14 December (2012).

73) **S. Chakravarty, W-C. Lai, Y. Zou, R.T. Chen, Photonic crystal microcavity engineering and high-density bio-patterning for chip-integrated microarray applications, Oral Presentation at SPIE Photonics West, San Francisco, CA (2012); Proc. of the SPIE 8212, 821220A (2012).

74) **S. Chakravarty, W-C. Lai, Y. Zou, R.T. Chen, On-chip sensing of volatile organic compounds in water by hybrid polymer and silicon photonic-crystal slot-waveguide devices, Oral Presentation at SPIE Photonics West, San Francisco, CA (2012); Proc. of the SPIE 8258, 825815 (2012).

75) **W-C. Lai, S. Chakravarty, Y. Zou, H.A. Drabkin, R.M. Gemmill, G.R. Simon, S.H. Chin, R.T. Chen, Silicon photonic crystal microcavity biosensors for label-free highly sensitive and specific lung cancer detection, Oral Presentation at IEEE Photonics, Burlingame, CA, WD3 (2012)

76) **Y. Zou, S. Chakravarty, W-C. Lai, R.T. Chen, Experimental detection of 1 pico-molar concentration from high-Q photonic crystal microcavity biosensors, Oral Presentation at IEEE Photonics, Burlingame, CA, MR3 (2012).

77) **W-C. Lai, S. Chakravarty, Y. Zou, R. T. Chen, Loss Engineered High Sensitivity Photonic Crystal Microcavities for Multiplexed Detection of Biomolecules, Rochester, NY, OSA Frontiers in Optics, FM3H (2012)

78) S. Chakravarty, W-C. Lai, Y. Zou, C-Y. Lin, R.T. Chen, Silicon nanomembrane based photonic crystal nanostructures for chip-integrated open sensor systems, (Invited)** Oral Presentation at International Conference on Optical Instruments and Technology Optoelectronic Devices and Integration (2011); Proc. of the SPIE 8198, 819802 (2011).

79) **S. Chakravarty, Photonic crystal microarray nano-platform for high throughput diagnostic assays of cancers, Oral Presentation at Hollings Cancer Center Developmental Cancer Therapeutics program Biomarker retreat, Medical University of South Carolina, Charleston, SC, October 14 (2011).

80) X. Wang, C-Y. Lin, S. Chakravarty, J.D. Luo, A-K-Y. Jen, R.T. Chen, Slow light enhanced E-O polymer nano-photonic modulator with ultra-high effective in-device r33, Conference of the Lasers and Electro-Optic Society CLEO, CTuN6 (2011) (Oral Presentation).

81) **S. Chakravarty, R.T. Chen, Photonic crystal slot waveguide spectroscopy detection of chemical warfare simulants, Conference of the Lasers and Electro-Optic Society CLEO, CThC4 (2011) (Oral Presentation).

82)**W-C. Lai, K. Moncivais, S. Chakravarty, X. Wang, C-Y. Lin, Z. J. Zhang, R.T. Chen, High density ink jet printing of biomolecules for photonic crystal-based microarray applications, Optical Sensors Topical Meeting, Toronto, Canada, 1084519 (2011).

83) **S. Chakravarty, W-C. Lai, X. Wang, C-Y. Lin, R.T. Chen, Photonic crystal slot waveguide optical absorption spectrometer for high-sensitivity near-infrared detection of xylene in water, Oral Presentation at SPIE Defense, Security and Sensing, Orlando, FL, CA (2011); Proc. of the SPIE 8032, 80320N (2011).

84) **S. Chakravarty, W-C. Lai, K. Moncivais, X. Wang, C-Y. Lin, Z. Zhang, R.T. Chen, Photonic crystal microarray nano-platform for high-throughput detection of biomolecules for diagnostic assays, Oral Presentation at SPIE Defense, Security and Sensing, Orlando, FL, CA (2011); Proc. of the SPIE 8034, 803402 (2011).

85) **S. Chakravarty, W-C. Lai, X. Wang, C-Y. Lin, R.T. Chen, Photonic crystal slot waveguide spectrometer for the detection of methane, Oral Presentation at SPIE Photonics West, San Francisco, CA (2011); Proc. of the SPIE 7941, 79410K (2011).

86) C-Y. Lin, X. Wang, B-S. Lee, W-C. Lai, S. Chakravarty, R T. Chen, Group Velocity Independent Coupling into Slow Light Photonic Crystal Waveguide, Oral Presentation, SPIE Photonics West, San Francisco, CA (2011); Proc. of the SPIE 7944, 79440K (2011).

87) C-Y. Lin, X. Wang, S. Chakravarty, W-C. Lai, R.T. Chen, Experimental Demonstration of Ultra-low loss coupling into slow light slotted photonic crystal waveguide on silicon nanomembrane, Integrated Photonics Research, Silicon and nanophotonics, OSA Technical Digest (CD) (Optical Society of America), paper IMF2 (2011).

88) R.T. Chen, S. Chakravarty, W-C. Lai, Photonic Crystal Microarray Nanoplatform for High-Throughput Highly Sensitive Detection and Identification of Cancers, Poster Presentation at National Cancer Institute, Cancer Detection and Diagnostic Technologies for Global Health, Rockville, MD, August 21-23, TTT-6, Page 61 (2011)

89) C-Y. Lin, B-S. Lee, X. Wang, W-C. Lai, S. Chakravarty, Y. Liu, D. Kwong, R.T. Chen, J. Luo, A. K. Y. Jen, Ultra-compact silicon nanophotonic modulator based on electro-optic polymer infiltrated slot photonic crystal waveguide, Oral Presentation at SPIE Photonics West, San Francisco, CA (2010), Proc. of the SPIE 7607, 76070D (2010).

90) X. Wang, S. Chakravarty, B-S. Lee, C. Lin, J. Luo, A.K.Y. Jen, R. T. Chen, Nanophotonic electro-optic polymer modulator based on photonic bandgap engineering, Integrated Photonics and Nanophotonics Research and Applications (IPNRA), PDPC4,Jul.12-15 (2009),Oahu, Hawaii.

91) X. Wang, S. Chakravarty, B-S. Lee, C. Lin, R. T. Chen, Electro-optic polymer based nanophotonic modulator with ultra-high efficiency, Avionics, Fiber-Optics and Photonics Technology Conference, pages 86-87 (2009).

92) Y-F. Cheng, W-C. Lo, M-J. Chen, P. Huang, C. Chen, S. Chakravarty, P. Yu, R. Dover, Improving cost of ownership on KLA-Tencor wafer fab reticle inspections by implementing pixel migration via new STARlight2+ capability, Proc. of the SPIE, 7122, 71223J (2008).

93) C-T. Huang, Y-F. Cheng, S-M. Kuo, C-H. Huang, S. Chakravarty, J. Huang, J. Lin, D. Wang, Inspectability of PSM masks for 32nm node using STARlight2+, Proc. of the SPIE, 7028, 70282P (2008).

94) A. Lan, J. Hsu, S. Chakravarty, V. Hsu, E. Chen, E. Lu, J. Miller, Fast integrated die-to-die transmitted, reflected and STARlight-2 defect inspection on memory masks, Proceedings of the SPIE, 7028, 70281J (2008).

95) S-M. Yen, S. Chakravarty, J. Huang, J. Miller, R. Dover, D. Wang, Improving COO on KLA-Tencor wafer fab reticle inspections by implementing pixel migration as new STARlight2+, Proc. of the SPIE, 7028, 702820 (2008).

96) D. Stoler, W. Ruch, W. Ma, S. Chakravarty, S. Liu, R. Morgan, J. Valadez, B. Moore, J. Burns, Optimizing defect inspection strategy through the use of design-aware database control layers, Proc. of the SPIE, 6730, 67303L (2007).

97) J-P. Sier, E.H. Lu, K. Bhattacharyya, S. Chakravarty, M. Lang, H. Schmalfuss, J. Heumann, T. Schulmeyer, Enhancing productivity and sensitivity in mask production via a fast integrated T+R pattern inspection and STARlight-2TM contamination inspection on critical layers, Poster Presentation, SPIE Photomask Japan, April 17-19 (2007), Yokohama, Japan.

98) S. Chakravarty, P. Bhattacharya, Z. Mi, Electrically injected quantum dot photonic crystal microcavity light emitting arrays with air-bridge nano-contacts, Oral Presentation IEEE LEOS, Oct 29-Nov 2 (2006), Montreal, Quebec, Canada; art.no. 4054336, 619 (2007)

99) S. Chakravarty, Z. Wu, and P. Bhattacharya, Electrically injected quantum dot photonic crystal microcavity light emitters and microcavity arrays, Oral Presentation at 2006 Engineering Graduate Student Symposium, University of Michigan Ann Arbor.

100)S. Chakravarty, Y. Kang, J. Topoľančik, P. Bhattacharya, M.E. Meyerhoff, S. Chakrabarti, Photonic crystal microcavity source based ion sensor,” Oral Presentation 4th IEEE Conference on Sensors, Oct 31-Nov 3 (2005), Irvine, CA; Proc. of IEEE Sensors, 1597807, 746 (2005)

101)S. Chakravarty, Y. Kang, J. Topoľančik, P. Bhattacharya, M.E. Meyerhoff, S. Chakrabarti, Photonic crystal microcavity source based chemical sensor, Oral Presentation Optics East Oct 22-26 (2005), Boston, MA; Proceedings of SPIE 600504 (2005).

102)S. Chakravarty, J. Topoľančik, P. Bhattacharya, S. Chakrabarti, Electrically injected quantum-dot bottom emitting photonic crystal single mode microcavity light source, Oral Presentation Device Research Conference, Jun 21-23 (2005), Santa Barbara, CA; 1553037, 19 (2005).

103)P. Chen, S. Chakravarty, P. Boolchand, and M. Micoulaut, Aging, reversibility window and fragility in GexPxSe1-2x bulk alloy glasses, Annual APS March Meeting, March 22-26 (2004), Montreal, Quebec, Canada

104)S. Chakravarty, D.G. Georgiev, P. Boolchand, M. Micoulaut, Self-Organization in PxGexSe1-2x glasses, Oral Presentation APS March Meeting, Mar 3-7 (2003), Austin, TX.

105)S. Chakravarty, D.G. Georgiev, P. Boolchand, Thermally reversing window in PxGexSe1-2x glasses, Oral Presentation APS March Meeting, Mar 18-22 (2002), Indianapolis, IN.

Journals Conferences

Patents Top of Page

1) S. Chakravarty, R.T. Chen, Photonic Crystal Microarray Device for Label-free Multiple Analyte Sensing, Biosensing and Diagnostic Assay Chips, Patent US 8,293,177 (Issued: 10/23/2012).

2) S. Chakravarty, R.T. Chen, Photonic Crystal Slot Waveguide Miniature On-Chip Absorption Spectrometer, Patent US 8,282,882 (Issued: 10/09/2012).

3) S. Chakravarty, R.T. Chen, Method for Label-Free Multiple Analyte Sensing, Biosensing and Diagnostic Assay, Patent US 8,580,200 (Issued 10/29/2013).

4) S. Chakravarty, R.T. Chen, Method for the Chip-Integrated Spectroscopic Identification of Solids, Liquids, and Gases, Patent US 8,585,974 (Issued 11/12/2013).

5) S. Chakravarty, A. Hosseini, R.T. Chen, Packaged chip for multiplexing photonic crystal waveguide and photonic crystal slot waveguide devices for chip-integrated label-free detection and absorption spectroscopy with high throughput, sensitivity, and specificity, Patent US 8,636,955 (Issued 01/28/2014).

6) S. Chakravarty, R.T. Chen, Photonic Crystal MicroArray Layouts for Enhanced Sensitivity and Specificity of Label-Free Multiple Analyte Sensing, Biosensing and Diagnostic Assay, Patent US 8,623,284 (Issued 01/17/2014).

7) S. Chakravarty, R.T. Chen, Fabrication Tolerant Design for the Chip-Integrated Spectroscopic Identification of Solids, Liquids, and Gases, Patent US 8,617,471 (Issued 12/31/2013).

8) S. Chakravarty, A. Hosseini, R.T. Chen, Method for Chip-Integrated Label-Free Detection and Absorption Spectroscopy with High Throughput, Sensitivity, and Specificity, Patent US 9,063,135 (Issued 6/23/2015).

9) S. Chakravarty, R.T. Chen, Method for the Chip-Integrated Spectroscopic Identification of Solids, Liquids, and Gases, Patent US 14/089,759 (Allowed 06/05/2015)

10) S. Chakravarty, A. Hosseini, R. T. Chen, Packaged Chip For Multiplexing Photonic Crystal Microcavity Coupled Waveguide And Photonic Crystal Slot Waveguide Devices For Chip-Integrated Label-Free Detection And Absorption Spectroscopy With High Throughput, Sensitivity, Specificity, And Wide Dynamic Range, Patent US 14/165,554 (Allowed 6/12/2015)

11) S. Chakravarty, Y. Guo, R.T. Chen, Measurement Methods and Systems with Two-Dimensional Photonic Crystal MicroArray for Highly-Sensitive Label-Free Multiple Analyte Sensing, Biosensing and Diagnostic Assay, Patent Application #14/308,671 (Filed 06/18/2014).

12) S. Chakravarty, R. Safian, Electro-optic modulators that include caps for optical confinement, US20220317483A1 (2021), EP4067982A1 (2022)

Teaching Top of Page

EOP 543L / EOP 545L Fall 2021 Fall 2022 Fall 2023 Fall 2024 Fall 2025 (EOP 545L combining EOP 541L and EOP 543L)
EOP 605 Spring 2022 (previously EOP 604) Spring 2023 Spring 2024
EOP 504 Spring 2025 Spring 2026
ECE 333 Fall 2023 Spring 2024
ECE 506 Fall 2025 Spring 2026

News Top of Page

January 2026: Ifeanyi passed PhD candidacy exam. Congratulations Ifeanyi!!

May 2025: Sheilah receives SPIE Optics and Photonics Scholarship $5,000. Congratulations Sheilah!!

May-July 2025: NSF REU at the University of Dayton (Year 3)

May 2024: We receive a NSF RET grant for University of Dayton in Semiconductor Workforce Development (co-PI)

May-July 2024: NSF REU at the University of Dayton (Year 2)

April 2024: Jianhao, Asela and Sam receive summer fellowships from University of Dayton. Congratulations!!

April 2024: Asela passed PhD candidacy exam. Congratulations Asela!!

March 2024: Jianhao receives award for best graduate student in Electro-Optics and Photonics for 2023. Congratulations Jianhao!!

March 2024: Jianhao passed PhD candidacy exam. Congratulations Jianhao!!

November 2023: Asela Perera got SPIE Travel Grant to attend SPIE Photonics West 2024. Congratulations Asela!!

September 2023: Asela Perera passed Part 1 of EOP PhD Candidacy exam. Congratulations Asela!!

August 2023: We received a NSF MRI grant for a direct write lithography tool at the University of Dayton (co-PI)

August 2023: Our group receives second 3-year NSF research grant of $540,000. Thank you NSF!!

May-August 2023: NSF REU at the University of Dayton (Year 1)

April 2023: Jianhao and Asela receive summer fellowships from University of Dayton. Congratulations!!

March 2023: We receive a NSF REU grant for University of Dayton in Semiconductor Electronics and Photonics

February 2023: Jianhao Shen passed Part 1 of EOP PhD Candidacy exam. Congratulations Jianhao!!

January 2023: Jianhao Shen got SPIE Travel Grant to attend SPIE Defense and Commercial Sensing 2023. Congratulations Jianhao!!

January 2023: Daniel Donnelly got SPIE Travel Grant to attend SPIE Defense and Commercial Sensing 2023. Congratulations Danny!!

August 2022: Our group receives first NSF research grant of $338,000. Thank you NSF!!

August 2022: Jianhao Shen receives his MS degree in EOP. Jianhao is also admitted to the EOP PhD program. Congratulations Jianhao!!

Sponsors Top of Page

	Principal Investigator Award #: 2315085: PIC: Charge Trapped Photonic Devices for Computing, Sensing and Sequencing Applications
	Principal Investigator Award #: 2210707 :Collaborative Research: PIC: Slow Wave Enhanced Electrooptically Tuned Michelson Interferometer Biosensor for On-Chip Dual Polarization Interferometry
	Principal Investigator Award #: 2244146: REU Site: Semiconductor Electronics and Photonics at University of Dayton
	Co-Principal Investigator Award #: 2320641: Equipment: Acquisition of a laser direct-write photolithography system

Previous Research Sponsors

Openings Top of Page

Open PhD Position

We are always interested to hear from prospective PhD students interested to pursue research in silicon photonics for application in chem-bio sensing and computing. Candidates should have a Masters in Electrical Engineering or Materials Science with some exposure to semiconductor device physics and/or materials processing. Ideal candidates would also have some exposure to optics/ photonics. Interested candidates would first need to be admitted into the PhD program in the Department of Electro-Optics and Photonics at the University of Dayton.

Photos Top of Page

In the Optical Measurements Lab
In the Cleanroom	Photolithography	Sputter/ Thin Film Deposition
At SPIE DCS 2023 Orlando, FL
NSF REU 2023 University of Dayton