Dr. Nibir K. Dhar Profile

Dr. Nibir K. Dhar

Professor

SPIE Involvement:

Conference Program Committee | Conference Chair | Track Chair | Author | Editor

Publications (140)

Proceedings Article | 10 October 2023 Presentation + Paper

High-performance graphene-enhanced HgCdTe photodetectors for uncooled extended infrared band sensing and imaging

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Samiran Ganguly, Latika Chaudhary, Harry Efstathiadis

Proceedings Volume 12687, 126870A (2023) https://doi.org/10.1117/12.2679887

KEYWORDS: Graphene, Mercury cadmium telluride, Mid-IR, Photodetectors, Boron, Doping, Infrared sensors, Infrared imaging, Infrared radiation, Chemical species

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Proceedings Article | 10 October 2023 Presentation

The Convergence Laboratory Program at Virginia Commonwealth University

Nibir Dhar

Proceedings Volume PC12687, PC1268702 (2023) https://doi.org/10.1117/12.2677662

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Proceedings Article | 15 June 2023 Paper

High efficiency metastructure-based emitter and photodetector for imaging

Kwong-Kit Choi, Patrick Oduor, Nibir Dhar, Achyut Dutta

Proceedings Volume 12514, 1251402 (2023) https://doi.org/10.1117/12.2666267

KEYWORDS: Light emitting diodes, Quantum efficiency, Avalanche photodetectors, Indium gallium arsenide, Airglow, Optical gratings, Design and modelling, Absorption, Photocurrent, Modeling

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Proceedings Article | 15 June 2023 Presentation + Paper

Quantum modeling of next generation photon detectors

Samiran Ganguly, Avik Ghosh, Nibir Dhar

Proceedings Volume 12514, 1251405 (2023) https://doi.org/10.1117/12.2663061

KEYWORDS: Quantum devices, Scattering, Modeling, Quantum physics, Quantum modeling, Quantum channels, Electrons, Superlattices, Quantum simulation, Quantum features

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Proceedings Article | 15 June 2023 Presentation

Development of graphene-enhanced HgCdTe photodetectors for uncooled mid-wave infrared detection

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Samiran Ganguly, Latika Chaudhary, Harry Efstathiadis

Proceedings Volume 12514, 1251408 (2023) https://doi.org/10.1117/12.2665080

KEYWORDS: Mid-IR, Mercury cadmium telluride, Photodetectors, Sensors, Graphene, Remote sensing, Boron, X-rays, Spatial resolution, Space operations

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Proceedings Article | 13 June 2023 Presentation + Paper

Circuits and systems modeling of quantum systems in SPICE

Samiran Ganguly, Kerem Camsari, Avik Ghosh, Nibir Dhar

Proceedings Volume 12517, 1251708 (2023) https://doi.org/10.1117/12.2663166

KEYWORDS: Device simulation, Quantum simulation, Quantum systems, Spintronics, Quantum computing, Modeling, Magnetism, Computer simulations, Quantum modeling, Quantum technologies

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Proceedings Article | 15 March 2023 Presentation + Paper

High-performance graphene-enhanced HgCdTe photodetectors for uncooled mid-wave infrared sensing

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Samiran Ganguly, Latika Chaudhary, Harry Efstathiadis

Proceedings Volume 12430, 124300U (2023) https://doi.org/10.1117/12.2656701

KEYWORDS: Graphene, Mercury cadmium telluride, Mid-IR, Photodetectors, Boron, Doping, Photocurrent, Dark current, Electrons, Chemical species

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Proceedings Article | 30 September 2022 Presentation + Paper

High-performance graphene-enhanced HgCdTe mid-wave infrared photodetector development

John Zeller, Ashok Sood, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Samiran Ganguly, Randy Jacobs, Latika Chaudhary, Harry Efstathiadis

Proceedings Volume 12234, 122340C (2022) https://doi.org/10.1117/12.2637897

KEYWORDS: Graphene, Mercury cadmium telluride, Mid-IR, Sensors, Photodetectors, Infrared sensors, Doping, Boron, Electrons

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Proceedings Article | 23 June 2022 Paper

Low noise uncooled 2.0+µm APD for photon counting imaging and LIDAR applications

Patrick Oduor, Abbas Haddadi, Kwong-Kit Choi, Seth Bank, Joe Campbell, Nibir Dhar, Jack Woods, Achyut Dutta

Proceedings Volume 12107, 121070B (2022) https://doi.org/10.1117/12.2630847

KEYWORDS: Avalanche photodetectors, Quantum efficiency, Aluminum, LIDAR, Absorption, Ionization, Sensors, Mercury cadmium telluride, Signal to noise ratio, Gallium antimonide

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Proceedings Article | 23 June 2022 Paper

Low-noise InGaAs APD based on micro-scaled photonic structures for low light imaging application

Kwong-Kit Choi, Patrick Oduor, Nibir Dhar, Achyut Dutta

Proceedings Volume 12107, 121070F (2022) https://doi.org/10.1117/12.2623783

KEYWORDS: Quantum efficiency, Light emitting diodes, Avalanche photodetectors, Silver, Sensors, Indium gallium arsenide, Resonators, Absorption, Photons, Metals

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Proceedings Article | 31 May 2022 Presentation + Paper

Development of high-performance graphene-HgCdTe detector technology for mid-wave infrared applications

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Randy Jacobs, Samiran Ganguly, Sheikh Ahmed, Farjana Tonni, Avik Ghosh, Latika Chaudhary, Harry Efstathiadis

Proceedings Volume 12091, 1209108 (2022) https://doi.org/10.1117/12.2622239

KEYWORDS: Graphene, Sensors, Mercury cadmium telluride, Mid-IR, Photodetectors, Infrared sensors, Doping, Boron

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Proceedings Article | 11 August 2021 Presentation + Paper

Development of high-performance graphene-HgCdTe detector technology for mid-wave infrared applications

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Randy Jacobs, Samiran Ganguly, Avik Ghosh, Latika Chaudhary, Harry Efstathiads

Proceedings Volume 11831, 1183103 (2021) https://doi.org/10.1117/12.2598866

KEYWORDS: Graphene, Mercury cadmium telluride, Sensors, Mid-IR, Doping, Boron, Photodetectors, Interfaces, Raman spectroscopy, Infrared sensors

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Proceedings Article | 5 August 2021 Open Access

Infrared technology: what is on the horizon?

Nibir Dhar

Proceedings Volume 11841, 118410H (2021) https://doi.org/10.1117/12.2600636

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Proceedings Article | 3 August 2021 Paper

Controlling light penetration depth to amplify the gain in ultra-fast silicon APDs and SPADs using photon-trapping nanostructures

Ahasan Ahamed, Cesar Bartolo-Perez, Ahmed Sulaiman Mayet, Soroush GhandiParsi, Xiangnan Zhou, Julien Bec, Nibir K. Dhar, Ekaterina P. Devine, Shih-Yuan Wang, Gerard Ariño-Estrada, Laura Marcu, M. Saif Islam

Proceedings Volume 11800, 118000F (2021) https://doi.org/10.1117/12.2597835

KEYWORDS: Absorption, Silicon, Avalanche photodetectors, Photonic nanostructures, Nanostructures, Avalanche photodiodes, Etching, Photonic devices, Photodiodes, Sensors

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Proceedings Article | 21 May 2021 Paper

Development of high-performance graphene-HgCdTe detector technology for mid-wave infrared applications

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Randy Jacobs, Samiran Ganguly, Avik Ghosh, Latika Chaudhary, Harry Efstathiadis

Proceedings Volume 11723, 117230I (2021) https://doi.org/10.1117/12.2590712

KEYWORDS: Graphene, Sensors, Mercury cadmium telluride, Mid-IR, Doping, Boron, Interfaces, Photodetectors, Chemical species, Infrared sensors

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Proceedings Article | 12 April 2021 Presentation + Paper

Novel IR photodetectors and energy harvesting devices

Kwong-Kit Choi, Achyut Dutta, Nibir Dhar

Proceedings Volume 11723, 1172303 (2021) https://doi.org/10.1117/12.2590229

KEYWORDS: Energy harvesting, Photodetectors, Absorption, Sensors, Quantum efficiency, Nanostructures, Solar cells, Infrared detectors, Wafer-level optics, Thin films

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Proceedings Article | 12 April 2021 Presentation + Paper

eSWIR and MWIR gain-based photodetectors in type-II superlattices: past, present, and future

A. Haddadi, A. Dutta, N. Dhar

Proceedings Volume 11723, 1172305 (2021) https://doi.org/10.1117/12.2596142

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Proceedings Article | 20 September 2020 Paper

Development of high-performance graphene-HgCdTe detector technology for Mid-wave Infrared Applications

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Samiran Ganguly, Avik Ghosh

Proceedings Volume 11530, 115300I (2020) https://doi.org/10.1117/12.2572904

KEYWORDS: Sensors, Mid-IR, Infrared sensors, Detector development, Mercury cadmium telluride, Graphene, Earth sciences, Photodetectors, Remote sensing, Night vision

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Proceedings Article | 22 August 2020 Paper

Development of high-performance graphene-HgCdTe detector technology for mid-wave infrared applications

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Samiran Ganguly, Avik Ghosh

Proceedings Volume 11503, 115030M (2020) https://doi.org/10.1117/12.2571232

KEYWORDS: Sensors, Graphene, Mercury cadmium telluride, Mid-IR, Silicon, Interfaces, Photodetectors, Infrared sensors, Detector development

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Proceedings Article | 21 August 2020 Presentation + Paper

Gender classification of full-body biological motion of aperiodic actions using machine learning

Madeline Navarro, Alexander Glandon, Nibir Dhar, Khan Iftekharuddin

Proceedings Volume 11509, 1150904 (2020) https://doi.org/10.1117/12.2569538

KEYWORDS: Machine learning, Biological research, Kinematics, Feature extraction, Motion models, Matrices, Data modeling, Statistical analysis, Motion measurement

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Proceedings Article | 27 April 2020 Presentation

Density functional theory based bandstructure analysis of graphene-HgCdTe heterostructure mid-wave infrared detector for Earth science applications (Conference Presentation)

Samiran Ganguly, Sheikh Ahmed, Avik Ghosh, Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar

Proceedings Volume 11388, 1138803 (2020) https://doi.org/10.1117/12.2559001

KEYWORDS: Mid-IR, Sensors, Infrared sensors, Earth sciences, Heterojunctions, Mercury cadmium telluride, Sensor performance, Graphene, Photodetectors, Physics

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Proceedings Article | 10 October 2019 Presentation + Paper

Development of high-performance detector technology for UV and IR applications

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Samiran Ganguly, Avik Ghosh, Russell Dupuis

Proceedings Volume 11151, 1115113 (2019) https://doi.org/10.1117/12.2536257

KEYWORDS: Sensors, Mid-IR, Mercury cadmium telluride, Ultraviolet radiation, Graphene, Silicon, Gallium nitride, Infrared sensors, Photodetectors, Avalanche photodetectors

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Proceedings Article | 9 September 2019 Presentation + Paper

Development of high-performance graphene-HgCdTe detector technology for mid-wave infrared applications

Ashok Sood, John Zeller, Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Samiran Ganguly, Avik Ghosh

Proceedings Volume 11129, 1112906 (2019) https://doi.org/10.1117/12.2531651

KEYWORDS: Sensors, Mid-IR, Infrared sensors, Detector development, Graphene, Earth sciences, Photodetectors, Remote sensing, Night vision, Computer engineering

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Proceedings Article | 9 September 2019 Presentation + Paper

Development of nanostructured antireflection coatings for infrared sensing applications

Ashok Sood, John Zeller, Adam Sood, Gopal Pethuraja, Roger Welser, Harry Efstathiadis, Anand Sampath, Nibir Dhar

Proceedings Volume 11129, 111290I (2019) https://doi.org/10.1117/12.2531642

KEYWORDS: Antireflective coatings, Nanostructuring, Infrared detection, Infrared technology, Long wavelength infrared, Roads, Optical components, Ultraviolet radiation, Night vision, Infrared sensors

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Proceedings Article | 7 May 2019 Presentation + Paper

Recombination processes in InAs/InAsSb type II strained layer superlattice MWIR nBn detectors

R. DeWames, J. Schuster, E. DeCuir, N. Dhar

Proceedings Volume 11002, 110020W (2019) https://doi.org/10.1117/12.2521907

KEYWORDS: Sensors, Quantum efficiency, Mid-IR, Heterojunctions, Temperature metrology, Absorption, Superlattices, Diodes, Diffusion, Solids

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There is great interest in MWIR Ga-free type II strained layer superlattice (T2SLS) nBn detectors for background limited photodetectors (BLIP) operating at temperatures higher than InSb (T ≥ 150K compared to T≈ 80-90K). Recently, Ting et al. [Proc. SPIE, Vol. 10624, 1062410-1 (2018)] reported on measurements of the dark current and quantum efficiency (QE) for e-SWIR (λ>1.7 μm), MWIR, and LWIR Ga-free nBn T2SLS detectors. Of particular interest is the reported MWIR nBn T2SLS data, since the measured dark current and QE provide the opportunity to analyze the measured detector optoelectronic characteristics using optical properties obtained separately from the hole minority carrier lifetime and optical absorption coefficient data, hence no adjustable parameters. The goal is to develop and utilize robust modeling techniques to explain real, measured nBn detector data to understand the technology limitations and the improvements needed to optimize performance and device designs. A notable result is the observation that the dark current data under reverse bias (-100 mV < bias ≤ 0 mV) obeys the ideal diode equation, where the saturation dark current is in agreement with the radiative recombination rate obtained from the measured absorption coefficient and a 9 μs Shockley-Read-Hall (SRH) lifetime obtained from the measured hole lifetime data. Most important is that the expected generation-recombination (G-R) space charge current based on the 9 μs SRH lifetime is not observed as expected for an ideal nBn heterojunction detector and that increasing excess dark currents are observed with decreasing temperature. The in-band external QE measured at 100K is in the range of 30% and is observed to increase with increasing operating temperature which indicates effects influenced by hole mobility anomalies. In contrast to the above listed observations, the Type II Ga-free nBn detector data reported by D. Ting et al. [Appl. Phys. Lett., 113, 021101, 2018] exhibits a hole energy barrier, G-R dark current like characteristics, and both temperature/voltage dependent QE.

Proceedings Article | 7 May 2019 Paper

Ultra-thin super absorbing photon trapping materials for high-performance infrared detection

Hossein Rabiee-Golgir, Soroush Ghandiparsi, Ekaterina Ponizovskaya Devine, Ahmed Mayet, Cesar Bartolo-Perez, Priyalal Wijewarnasuriya, Nibir Dhar, M. Saif Islam

Proceedings Volume 11002, 110020T (2019) https://doi.org/10.1117/12.2518690

KEYWORDS: Infrared detection

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The performance of mid- and long-wavelength infrared (IR) detectors is still restricted with the dark current characteristics and associated noise behavior. In this work, we propose reducing the dark current and related noise of the IR detectors to elevate high operating temperature and improve the detector quantum efficiency (QE), by using a thin absorption layer of IR absorbing materials like lead selenide (PbSe) and mercury cadmium telluride (HgCdTe). A photon bending and trapping mechanism based on integrated micro/nanoscale holes was employed to ensure high quantum efficiency despite using a thin absorbing layer. Using finite-difference time-domain (FDTD) method, the effect of embedded hole arrays on the optical absorption enhancement of ultra-thin PbSe and HgCdTe has been investigated. The calculated optical absorptions in ultra-thin IR structures without holes were compared with that of similar structures embedded with hole arrays. The optical absorption in 2 μm thick PbSe film without holes is less than 5% for 3-5 μm mid-IR wavelengths. Although applying conventional anti-reflecting (AR) coatings leads to a slightly higher absorption, it can cause higher dark current due to increased surface traps. Integration of hole arrays in 2 μm thick PbSe film has shown a significant optical absorption enhancement, up to 20% at 4.5 μm wavelength. This is equivalent to more than 2- and 4-folds' enhancement compared to a 2 μm thick flat-surface structure with AR and without AR, respectively. In addition, embedding the hole arrays in 1.2 μm thick HgCdTe IR films enhances the optical absorption up to 75% at 4.5 μm, which is more than 4 times higher than that in HgCdTe structure without holes. Additionally, the optical absorption in 1.2 μm thick HgCdTe film with periodic array of photon-trapping micro-holes enhances to 27% at 10 μm, long-IR wavelength. This is more that 3 times higher than that in HgCdTe films without holes. Our work revealed that the embedding hole arrays not only enhances the optical absorption in IR ultra-thin structures but also can reduce that material filling ratio to ~50%, which leads to a lower dark current, ensuring higher temperature operation of the IR detectors.

Proceedings Article | 1 March 2019 Paper

Demonstration of uniform and reliable GaN p-i-p-i-n separate-absorption and multiplication ultraviolet avalanche photodiode arrays with large detection area

Mi-Hee Ji, Hoon Jeong, Marzieh Bakhtiary-Noodeh, Shyh-Chiang Shen, Theeradetch Detchprohm, Ashok Sood, P. Parminder Ghuman, Sachidananda Babu, Nibir Dhar, Jay Lewis, Russell Dupuis

Proceedings Volume 10918, 1091814 (2019) https://doi.org/10.1117/12.2507880

KEYWORDS: Gallium nitride, Avalanche photodiodes, Absorption, Ultraviolet radiation, Detector arrays, Metalorganic chemical vapor deposition, Back illuminated sensors, UV optics

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Proceedings Article | 15 May 2018 Presentation + Paper

Analytical model for design-optimization and performances of fabricated broadband (VIS-SWIR) photodetector for image sensor and optical communication applications

Jaydeep Dutta, Patrick Oduor, Achyut Dutta, Nibir Dhar

Proceedings Volume 10656, 106560N (2018) https://doi.org/10.1117/12.2311596

KEYWORDS: Photodetectors, Absorption, Indium gallium arsenide, Quantum efficiency, Optical communications, Diffusion, Image sensors, Modulation, Optical instrument design, Visible radiation

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Proceedings Article | 14 May 2018 Paper

Considerations in the development of a foveated imaging system for unmanned aerial vehicles (UAVs)

Andrew O'Neill, Joshua Davidson, Tim Kane, Ram Narayanan, Nibir Dhar

Proceedings Volume 10656, 1065610 (2018) https://doi.org/10.1117/12.2305520

KEYWORDS: Imaging systems, Spatial light modulators, Image processing, Image resolution, Unmanned aerial vehicles, Data modeling, Freeform optics, Eye, Cameras, Mirrors

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Proceedings Article | 14 May 2018 Paper

Finite size narrow-band transmission filters for real-time short wave IR spectroscopy and imaging

Ryan Green, Vitaliy Avrutin, Ümit Özgür, Nibir Dhar, Erdem Topsakal

Proceedings Volume 10656, 106561U (2018) https://doi.org/10.1117/12.2304665

KEYWORDS: Optical filters, Imaging spectroscopy, Dielectrics, Short wave infrared radiation, Dielectric filters, Image filtering, Infrared spectroscopy, Infrared imaging, Spectroscopy, Fabry–Perot interferometers

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Proceedings Article | 9 May 2018 Presentation + Paper

Shockley-Read-Hall (SRH) recombination dark current in planar diffused P+n heterostructure InP/In0.53Ga0.47As/InP high density small pitch Focal Plane Arrays (FPAs)

R. DeWames, E. DeCuir, J. Schuster, N. Dhar

Proceedings Volume 10624, 1062405 (2018) https://doi.org/10.1117/12.2315838

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Proceedings Article | 19 September 2017 Presentation + Paper

Development of nanostructured antireflection coatings for infrared technologies and applications

Gopal Pethuraja, John Zeller, Roger Welser, Harry Efstathiadis, Pradeep Haldar, Priyalal Wijewarnasuriya, Nibir Dhar, Ashok Sood

Proceedings Volume 10404, 104040S (2017) https://doi.org/10.1117/12.2277957

KEYWORDS: Antireflective coatings, Nanostructuring, Transmittance, Reflectivity, Glasses, Silicon, Multilayers, Infrared technology, Reflection, Refractive index

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Proceedings Article | 7 September 2017 Presentation + Paper

Germanium photodetectors fabricated on 300 mm silicon wafers for near-infrared focal plane arrays

John Zeller, Caitlin Rouse, Harry Efstathiadis, Nibir Dhar, Priyalal Wijewarnasuriya, Ashok Sood

Proceedings Volume 10404, 104040H (2017) https://doi.org/10.1117/12.2277958

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Proceedings Article | 18 May 2017 Paper

Development of nanostructured antireflection coatings for infrared image sensing technologies

Gopal Pethuraja, John Zeller, Roger Welser, Ashok Sood, Harry Efstathiadis, Pradeep Haldar, Eric DeCuir, Priyalal Wijewarnasuriya, Nibir Dhar

Proceedings Volume 10209, 102090D (2017) https://doi.org/10.1117/12.2268856

KEYWORDS: Antireflective coatings, Nanostructuring, Transmittance, Glasses, Silicon, Reflectivity, Infrared imaging, Refractive index, Reflection, Infrared radiation

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Proceedings Article | 28 April 2017 Presentation + Paper

Materials for microbolometers: vanadium oxide or silicon derivatives

Andrew Voshell, Nibir Dhar, Mukti Rana

Proceedings Volume 10209, 102090M (2017) https://doi.org/10.1117/12.2263999

KEYWORDS: Microbolometers, Bolometers, Infrared radiation, Thin films, Semiconductors, Silicon films

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