Photonic Sciences Laboratory
Group Lead: Dr. Goutam K. Samanta, Professor
Physical Research Laboratory (PRL), Navrangpura, Ahmedabad - 380009, India
About Photonic Sciences Laboratory
The Photonic Sciences Laboratory at the Physical Research Laboratory (PRL), Ahmedabad, led by Prof. Goutam K. Samanta, is engaged in cutting-edge fundamental and applied research in the field of experimental quantum optics, nonlinear optics, quantum science and technology, structured optical beams, and photonics.
Despite decades of progress since the invention of the laser, the scarcity of suitable gain media across key spectral regions, from the ultraviolet (UV) to the terahertz (THz), continues to drive the need for advanced optical sources with tailored spectral, temporal, spatial, and quantum properties. We address these challenges by exploiting nonlinear optical frequency conversion to develop custom-engineered optical parametric oscillators (OPOs) for generating tunable classical and squeezed light, and innovative spontaneous parametric down-conversion (SPDC) sources for high-brightness single and entangled photons. Our research integrates nonlinear optics, structured light, and quantum engineering to generate and manipulate Airy, vector vortex, and Poincaré beams, while advancing broadband polarization entanglement, spatial multiplexing, and geometric phase control. These innovations enable next-generation technologies in quantum communication, quantum random number generation (QRNG), quantum sensing and imaging, and quantum information processing. By combining fundamental research with technology development, we bridge the gap between laboratory-scale discoveries and deployable quantum photonic systems.
About Group Leader
- Adjunct Professor: Indian Institute of Technology (IIT) Madras
- Associate Editor: Scientific Reports (2025–Present)
- Editorial Board Member: Journal of Optics, IOP (2021–Present)
- Guest Editor: IOP Collection on "Spotlight on India: Recent Advancements in Light-Matter Interaction"
- Guest Editor: IOP Special Issue on "Advances in Optics in India"
- Advisory Panel Member: Journal of Optics (till March 2021)
News & Recent Updates
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Sept 2026
Award Achievement: Mr. Anirban Ghosh received the EPS QEOD Travel Grant Student Award from the European Physical Society for his presentation at EPS QEOD Conference.
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May 2026
Scholarship Award: Mr. Anirban Ghosh was awarded the prestigious 2026 SPIE Optics and Photonics Scholarship.
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Apr 2026
PhD Defense: Dr. Ayan Kumar Nai successfully defended his PhD thesis titled "Sectioning and Multiplexing of the Spatial Distribution of Pair Photons for QRNG and QKD Network".
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Apr 2026
New Publication: Paper titled "Paraxial spin-induced vortex generation in epsilon-near-zero materials" published in Applied Physics Letters.
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Mar 2025
Poster Award: Mr. Anirban Ghosh won the Best Poster Award at the 33rd National Laser Symposium (NLS-33), Indore.
Research Thrusts
Research Projects & Initiatives
Parametric up-conversion of near and mid-IR optical radiation for hyperspectral photometry and imaging in astronomy and solar observations
Building the intracavity upconversion system based on the optical parametric oscillator for imaging of astronomical objects in near and mid-IR wavelength ranges using the standard imaging systems widely used for the visible spectrum.
Duration: 5 years
Status: Ongoing from July 2026
Funding agency: ANRF, India
Indigenous development of compact, hands-free, stable entangled photon sources at 810 nm
Development of high-brightness, robust entangled photon sources optimized for free-space and satellite-based quantum key distribution (QKD) initiatives in India.
Duration: 3 years
Status: Completed, March 2026
Funding agency: DST, India
Development of portable, quantum random number generator (QRNG): an extension to device-independent QRNG
Development of quantum random number generator (QRNG) at a high quantum bit rate, study the effect of Bell’s inequality on the randomness of the source, and development of device-independent QRNG.
Duration: 3 years
Status: Completed, March 2026
Funding agency: i-Hub, Pune, DST, India
Development of single-photon source-based quantum refractometry and displacement sensors
Development of the quantum sensor based on the Hong-Ou-Mandel interferometer for the displacement and refractive index measurement.
Duration: 2 years
Status: Completed, March 2023
Funding agency: DRDO, India
Product Development
JONAKI: Entangled Photon Source at 810 nm
JONAKI is a compact, field-deployable, entangled photon source designed for next-generation quantum communication, quantum sensing, and advanced research applications. Engineered for stability and performance, it generates non-collinear, degenerate polarization-entangled photon pairs at 810 nm, optimized for free-space and laboratory-based quantum experiments.
Download Brochure
SAMAY: Time-to-Digital Converter (TDC)
High-resolution time-to-digital converter for photon timing, coincidence measurements, and quantum optics experiments. Observe detection rates for up to four single-photon detectors, generate up to four coincidence pairs between any pair of connected detectors or trigger signals, and record every time tag for an exceptionally high number of detected photons, all with subnanosecond precision.
Download BrochureGroup Members
Mr. Vimlesh Kumar
Mechanical EngineerTopic: Quantum Optics, Nonlinear Optics, and Optomechanical Engineering
Mr. Rutuj Gharate
Electronics EngineerTopic: Electronics System Development, TDC Systems & QKD Hardware Implementation
Ms. Swagata Sarkar
DST Inspire PhD StudentTopic: Structured Single Photon Generation
Mr. Milan Jana
Project Associate-ITopic: Quantum Source and Quantum Sensing
Mr. Sanjan Roychowdhury
Project Associate-ITopic: Squeezed Light, Quantum Sensing and Ranging
Mr. Shubham Sharma
Junior Research FellowTopic: Nonlinear Interaction of Structured Beams
Mr. Siddhant Vernekar
Visiting PhD, IIT Delhi (June 2025-)Topic: Structured Optical Fields
Mr. Niravra Nag
Master's, IISER Kolkata (June 2025-)Topic: SPDC & Entanglement
Mr. Divyakanti Ghorui
Master's, IISER Pune (June 2025-)Topic: HOM Interferometry
Mr. Hitansh Luhar
Master's, DAIT Pune (June 2025-)Topic: Single-Photon Counting Systems
- Mr. Soham Acharya — Summer project, IISc Bangalore (15 May - 15 July, 2026)
- Mr. Tanay Nalawde — Academic Project Training, MIT WPU, Pune (19 Jan - 10 Jun, 2026)
- Ms. Aditi Kumari — Academic Project Training, NIT Patna (23 Mar - 15 May, 2026)
- Ms. Harsha N Jijish — Master Thesis 2025-2026, IISER Berhampur
- Mr. Gopal Sahu — Visiting Student, IIT Dharwad
- Mr. Niladri Das — PhD Student, IISc Bangalore
- Dr. Sandeep Singh — Postdoctoral Fellow, DTU Denmark
- Dr. Saumya Jyoti Sarkar — Postdoctoral Fellow, Chiba University, Japan
- Dr. Subith Kumar — Postdoctoral Fellow, University of the Witwatersrand, South Africa
- Dr. Deepika Yadav — Postdoctoral Fellow, Japan
- Mr. Anupam Pal — Master's Student, Abbe School of Photonics, Germany
- Dr. Varun Sharma — Postdoctoral Fellow, University of Graz, Austria
- Dr. Ravi Kiran Saripalli — Postdoctoral Fellow, University of New Orleans, USA
- Mr. Harshith Bachimanchi — PhD Student, University of Gothenburg, Sweden
- Dr. A S V Rao — JSPS Fellow, Chiba University, Japan
- Dr. Raghwinder Singh — Postdoctoral Fellow, Delaware University, USA
- Dr. Jabir M. V. — Postdoctoral Fellow, NIST Gaithersburg, USA
- Mr. Sabir Alam — PhD Student, Hong Kong University, Hong Kong
- Dr. Aadhi A. — Postdoctoral Fellow, INRS Varennes, Canada
- Dr. Apurv Chaitanya N. — Postdoctoral Fellow, Tecnologico de Monterrey, Mexico
Full List of Prizes, Awards & Recognitions
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EPS QEOD Travel Grant Student Award (Sept 2026)
Awarded to Mr. Anirban Ghosh by European Physical Society for contribution to EPS QEOD Conference.
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2026 SPIE Optics and Photonics Scholarship (May 2026)
Prestigious scholarship awarded to Mr. Anirban Ghosh by SPIE, USA.
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Best Poster Award — NLS-33 (Mar 2025)
Awarded to Mr. Anirban Ghosh for "High repetition rate mid-IR coherent radiation through 1064 nm CW pumped OPA, injection seeded with Multi-gigahertz OPO", 33rd National Laser Symposium (BRNS, RRCAT Indore & Medi-Caps Univ).
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Best PhD Thesis Award — Indian Laser Association (2024)
Awarded to Dr. Sandeep Singh for thesis "Generation and Characterization of Pair Photons for Quantum Sensing Applications" at 32nd DAE-BRNS NLS, RRCAT Indore.
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Best Poster Award — NLS-32 (2024)
Awarded to Ms. Chahat Kaushik for "Geometric phase induced tunable optimum output coupling in optical parametric oscillators".
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Best Poster Award — NLS-32 (2024)
Awarded to Mr. Anirban Ghosh for "Experimental Observation of Optical Hilbert's Hotel in Vector Beam".
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DST International Travel Grant (2023)
Awarded to Mr. Sandeep Singh to attend Frontiers in Optics + Laser Science (FiOLS) in Denver, Colorado, USA.
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URSI Young Scientist Award (2023)
Awarded to Mr. Anirban Ghosh to attend URSI GASS 2023 in Sapporo, Japan for "Hilbert Hotel: An experimental realization in polarization topological vortex beam".
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Outstanding Poster Presentation Award (2019)
Awarded to Mr. Anirban Ghosh for "Nonlinear generation of ultrafast, high power, higher order vector vortex beams", IISc Bangalore.
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Travel Grant Student Award (2019)
Awarded to Mr. Varun Sharma by European Physical Society (EPS) for CLEO/EUROPE-EQEC 2019, Munich, Germany.
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69th Lindau Nobel Laureate Meeting Participant (2019)
Selected participant: Mr. Varun Sharma, Lindau, Germany.
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Best Student Poster Contribution Award (2018)
Awarded to Mr. Varun Sharma at Europhoton Conference, Barcelona, Spain.
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Incubic / Milton Chang Travel Grant (2017)
Awarded to Mr. Jabir M. V. for Frontiers in Optics, Washington DC, USA.
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Best Poster Award — NLS-25 (2016)
Awarded to Mr. Jabir M. V. at KIIT University, Bhubaneswar.
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Best Poster Award — PHOTONICS 2016
Awarded to Mr. Apurv Chaitanya N. at IIT Kanpur.
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OSA Foundation Travel Grant (2016)
Awarded to Dr. Apurv Chaitanya N. for Frontiers in Optics, University of Rochester, USA.
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EPS Grant for Young Scientist (2016)
Awarded to Mr. Jabir M. V. at 7th EPS-QEOD Europhoton Conference, Vienna, Austria.
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EPS Grant for Young Scientist (2016)
Awarded to Dr. A. Aadhi at 7th EPS-QEOD Europhoton Conference, Vienna, Austria.
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Best Poster Award — RAOS (2016)
Awarded to Mr. Apurv Chaitanya N. at RAOS-2016 conference, Hyderabad University, May 6-7, 2016.
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SPIE Best Poster Award — ICTP (2016)
Awarded to Dr. A. Aadhi at Winter College on Optics: Optical Frequency Combs held at ICTP, Trieste, Italy during February 2016.
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Incubic / Milton Chang & OSA Travel Grant (2015)
Awarded to Dr. A. Aadhi by Optical Society of America (OSA) for Frontiers in Optics, San Jose, USA.
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Best Poster Award — NLS-24 (2015)
Awarded to Mr. Jabir M. V. at RRCAT, Indore.
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Student Presentation Award — SPIE (2015)
Awarded to Mr. Apurv Chaitanya N. at ICOP 2015, Calcutta University.
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Best Poster Award — Photonics (2014)
Awarded to Mr. Apurv Chaitanya N. at Photonics, IIT Kharagpur, December 13-16, 2014.
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Best Poster Award — NLS-24 (2015)
Awarded to Mr. Apurv Chaitanya N. at National Laser Symposium, Tirupoti, December 3-6, 2014.
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Best Poster Award — ICOP (2014)
Awarded to Mr. A. Aadhi at International Conference on Optics & Optoelectronics, Instruments Research & Development Establishment, Dehradun, March 5-8, 2014.
Journal Cover Pages
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APL Photonics Cover (June 2023)
Simple experimental realization of optical Hilbert Hotel using scalar and vector fractional vortex beams, APL Photonics, 8, 066105 (2023).
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Applied Optics Front Cover (January 2012)
Single-frequency, high-power, continuous-wave fiber-laser-pumped Ti:sapphire laser, Applied Optics, 51, 15-20 (2012).
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KIRAN Cover — Indian Laser Association (2010)
Stable, 9.6 W, continuous-wave, single-frequency, fiber-based green source at 532 nm, Optics Letters, 34, 1561-1563 (2009).
Magazine Highlights
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Laser Focus World Highlight (2011)
Dual-wavelength, two-crystal, continuous-wave optical parametric oscillator, Optics Letters, 36, 3033-3035 (2011).
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Laser Focus World Highlight (2011)
Multicrystal, continuous-wave, single-pass second-harmonic generation with 56% efficiency, Optics Letters 35, 3513-3515 (2010).
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Virtual Journal of Ultrafast Science Highlight (2009)
Continuous-wave optical parametric oscillator pumped by a fiber laser green source at 532 nm, Optics Letters, 34, 2255-2257 (2008).
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Laser Focus World (2008), Optics.org (2008), and Optics and Laser Europe Highlight (2009)
Continuous-wave, single-frequency, solid-state blue source for the 425-489 nm spectral range, Optics Letters, 33, 1228-1230 (2008).
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Top 10 Downloaded Paper — Optics Letters (Sept 2020)
Watt-level, ultrafast, tunable yellow source based on single-pass, fourth-harmonic generation of Cr2+:ZnS laser at 2360 nm, Optics Letters, 45, 5109-5112 (2020).
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Ranked 47th Top Downloaded Physics Paper — Scientific Reports (2017)
Robust, high brightness, degenerate entangled photon source at room temperature, Scientific Reports 7, 12613 (2017).
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Top 10 Downloaded Paper — Optics Letters (Consecutive Months 2017)
High power, high repetition rate, tunable broadband mid-IR source based on single-pass optical parametric generation of a femtosecond laser, Optics Letters, 42, 2886-2889 (2017).
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Top 10 Downloaded Paper — Optics Letters (June 2016)
Ultrafast optical vortex beam generation in the ultraviolet, Optics Letters, 41, 2715-2718 (2016).
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Top 10 Downloaded Paper — Optics Letters (Nonlinear Optics)
All-periodically poled, high-power, continuous-wave, single-frequency tunable UV source, Optics Letters 40, 33-36 (2015).
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Top 10 Downloaded Paper — Optics Letters (Nonlinear Optics)
High-power, high-repetition-rate, Yb-fiber laser based femtosecond source at 355 nm, Optics Letters, 40, 4269-4272 (2015).
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Top 10 Downloaded Paper — Optics Letters (Jan 2012)
Frequency-modulation-mode-locked optical parametric oscillator, Optics Letters, 37, 115-117 (2012).
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Top 10 Downloaded Paper — Optics Letters (May 2009)
Stable, 9.6 W, continuous-wave, single-frequency, fiber-based green source at 532 nm, Optics Letters, 34, 1561-1563 (2009).
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Top 10 Downloaded Paper — Optics Letters (Dec 2008)
Stable, High-power, continuous-wave, second-harmonic generation at 532 nm in periodically poled KTiOPO4, Optics Letters, 33, 2955-2957 (2008).
Lab Gallery, Media & Covers
Photonic Sciences Lab Members (2026)
Group photo at Physical Research Laboratory (PRL), Ahmedabad campus.
PhD Defense Celebration
Group celebration following a successful thesis defense at the lab.
NLS-33 Conference Delegation
Lab members participating and presenting research at National Laser Symposium.
High-Brightness SPDC Quantum Source
Experimental optical table setup for generating polarization-entangled photon pairs.
Multi-GHz Mid-IR OPO System
Tunable high-repetition-rate optical parametric oscillator running in the laboratory.
Hong-Ou-Mandel Interferometer
Two-photon interference assembly utilized for ultra-sensitive quantum sensing.
APL Photonics Cover (June 2023)
Featured cover publication on optical realization of the Hilbert Hotel paradox using fractional vortex beams.
New Ultrafast Yellow Laser Poised to Benefit Biomedical Applications (2020)
We have developed a new compact and ultrafast, high-power yellow laser. The tunable laser exhibits excellent beam quality and helps fill the need for a practical yellow light source emitting ultrafast pulses of light.
Goutam K. Samanta on Mentoring OPN (2020)
In this installment of Senior Member Insights, OPN talks with Goutam Samanta. Goutam is an associate professor and heads the Photonic Sciences Laboratory at Physical Research Laboratory, India. Prior to joining Physical Research Laboratory, Goutam obtained his Ph.D. at the Institute of Photonics Sciences (ICFO), Spain.
ICO/ICTP Gallieno Denardo Award Winner (2017)
Goutam Kumar Samanta, Physical Research Laboratory, Ahmedabad, India, for his significant contributions to the field of nonlinear optics, lasers and quantum optics, as well as his efforts in popularizing science among school students in India.
Applied Optics Front Cover (2012)
Front cover issue highlighting fiber-laser-pumped single-frequency Ti:sapphire laser.
KIRAN Cover (Indian Laser Association 2010)
Featured on the cover of KIRAN bulletin for high-power green laser source development.
Optics & Laser Europe (2008)
Covering the research work on high-power blue light generation.
PhD Theses Completed in the Group
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Dr. Ayan Kumar Nai (16th April 2026)
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Dr. Saumya Jyoti Sarkar (19th May 2025)
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Dr. Subith Kumar (17th October 2024)
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Dr. Sandeep Singh (04th March 2024)
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Dr. Varun Sharma (18th February 2020)
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Dr. Jabir M. V. (9th October 2018)
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Dr. Apurv Chaitanya N. (22nd July 2016)
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Dr. Aadhi A. (2nd February 2016)
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Dr. Goutam K. Samanta (2009 — ILA Best Thesis Award)
Complete List of Journal Publications
View Citation Matrix & Full Metrics on Google Scholar →
- High-power dual-pulse ultrafast optical parametric oscillator with tunable polarization, wavelength, temporal separation, and repetition Opticaopen.33046796 (2026)
- A projection-free approach toward mapping the structured polarization fields arXiv:2607.16672 (2026)
- Quantum sensing through bosonic-fermionic Bell-state transitions in two-photon interference arXiv:2606.14408 (2026)
- Geometric phase-assisted simple phase compensation enabling quantum key distribution using phase-shifted Bell states arXiv:2604.12272 (2026)
- Paraxial spin-induced vortex generation in epsilon-near-zero materials Applied Physics Letters 128, 141110 (2026)
- Free-space multi-user quantum network with high key rate arXiv:2511.00466 (2025)
- Beam-splitter-free, high-rate quantum key distribution inspired by intrinsic quantum mechanical spatial randomness of entangled photons arXiv:2509.10231 (2025)
- Classical-to-quantum transfer of geometric phase for non-interferometric phase measurement and manipulation of quantum state arXiv:2505.20108 (2025)
- Device-independent, high bit-rate quantum random number generator with beam-splitter-free architecture and live Bell test certification Optics Express 33, 44878-44889 (2025)
- Multi-GHz repetition rate, tunable ultrafast mid-IR source Optics Letters 50, 4906 - 4909 (2025)
- Non-interferometric measurement of geometric phase through stimulated second harmonic generation Applied Physics Letters 127, 031101 (2025)
- A perspective on 25 years of advances as reported in the Journal of Optics (Editorial) Journal of Optics 27, 060202 (2025)
- Beamsplitter-free, high bit-rate, quantum random number generator based on temporal and spatial correlations of heralded single-photons AVS Quantum Science 7, 011401 (2025)
- Dead-zone-free single-beam atomic magnetometer based on free-induction-decay of Rb atoms Applied Physics Letters 126, 044002 (2025)
- Talbot effect-based sensor measuring grating period change in subwavelength range Scientific Reports 14, 30872 (2024)
- Fast measurement of group index variation with optimum precision using Hong-Ou-Mandel interferometry APL Quantum 1, 046117 (2024)
- Evolution of C-point singularities and polarization coverage of Poincare-Bessel beam in self-healing process Scientific Reports 14, 16647 (2024)
- Harnessing nonlinear frequency upconversion of Talbot effect with flexible Talbot lengths Optics Express 32, 15967-15977 (2024)
- Dynamically tunable broadband output coupling of optical oscillators based on non-cyclic geometric phase mirror Editor's Pick APL Photonics 8, 116110 (2023)
- Near-video frame rate quantum sensing using Hong-Ou-Mandel interferometry Advanced Quantum Technologies 6, 202300177 (2023)
- Simple experimental realization of optical Hilbert Hotel using scalar and vector fractional vortex beams Cover Page, Featured APL Photonics 8, 066105 (2023)
- Controlling the coverage of full Poincare beams through second-harmonic generation Physical Review Applied 19, 034082 (2023)
- A tolerance-enhanced spontaneous parametric downconversion source of bright entangled photons Advanced Quantum Technologies 6, 2200121 (2023)
- Imaging inspired characterization of single photons carrying orbital angular momentum AVS Quantum Sci. 4, 015001 (2022)
- Tunable, high-power, high-order optical vortex beam generation in the mid-infrared Optics Express 30, 1195-1204 (2022)
- Tunable vortex beam generation using an optical parametric oscillator with an antiresonant-ring interferometer Optics Letters 46, 3235-3238 (2021)
- Nonlinear frequency conversion of 3D optical bottle beams generated using a single axicon Optics Letters 46, 657-660 (2021)
- Watt-level, ultrafast, tunable yellow source based on single-pass, fourth-harmonic generation of Cr2+:ZnS laser at 2360 nm Editor's Pick Optics Letters 45, 5109-5112 (2020)
- Multi-structured-beam optical parametric oscillator Optics Express 28, 21650-21658 (2020)
- Tunable ultraviolet vortex source based on a continuous-wave optical parametric oscillator Optics Letters 44, 4694-4697 (2019)
- Frequency-conversion of vector vortex beams with space-variant polarization in single-pass geometry Applied Physics Letters 115, 051101 (2019)
- Controlled generation of array beams of higher order orbital angular momentum and study of their frequency-doubling characteristics Scientific Reports 9, 10916 (2019)
- Single-pass, second-harmonic generation of high-power, ultrafast mid-IR Cr2+:ZnS laser at 2360 nm Optics Letters 44, 3522-3525 (2019)
- Tunable vector-vortex beam optical parametric oscillator Scientific Reports 9, 9578 (2019)
- Controlled generation of vortex and vortex dipole from a Gaussian pumped optical parametric oscillator Optics Express 27, 18123-18130 (2019)
- Controlling the bi-photon orbital angular momentum eigenmodes using asymmetric pump vortex beam Journal of Optics 21, 055201 (2019)
- High-power, high repetition-rate, ultrafast fibre laser based source of DUV radiation at 266 nm OSA Continuum 2, 99-106 (2019)
- Simultaneous generation of high-power, ultrafast 1D and 2D Airy beams and their frequency-doubling characteristics Optics Letters 43, 3957-3960 (2018)
- Orbital angular momentum exchange in a picosecond optical parametric oscillator Optics Letters 43, 3606-3609 (2018)
- On-axis intensity modulation-free, segmented, zero-order Bessel beams with tunable ranges Optics Letters 43, 3029-3032 (2018)
- High-power, continuous-wave, tunable mid-IR, higher-order vortex beam optical parametric oscillator Optics Letters 43, 2312-2315 (2018)
- Nonlinear frequency doubling characteristics of asymmetric vortices of tunable, broad orbital angular momentum spectrum Applied Physics Letters 112, 171102 (2018)
- High-power, high repetition rate, tunable, ultrafast vortex beam in the near-infrared Journal of Optics 20, 01LT01 (2018)
- Robust, high brightness, degenerate entangled photon source at room temperature Scientific Reports 7, 12613 (2017)
- Continuous-wave, singly resonant parametric oscillator-based mid-infrared optical vortex source Optics Letters 42, 3674-3677 (2017)
- Direct transfer of classical non-separable states into hybrid entangled two photon states Scientific Reports 7, 7331 (2017)
- High power, high repetition rate, tunable broadband mid-IR source based on single-pass optical parametric generation of a femtosecond laser Optics Letters 42, 2886-2889 (2017)
- High power, higher order ultrafast hollow Gaussian beams Applied Physics Letters 110, 211103 (2017)
- Controlled switching of orbital angular momentum in an optical parametric oscillator Optica 4, 349-355 (2017)
- Multi-gigahertz, femtosecond Airy beam optical parametric oscillator pumped at 78 MHz Scientific Reports 7, 43913 (2017)
- Self-healing highly-chirped fiber laser at 1.0 um Optics Express 24, 27577-27586 (2016)
- Frequency-doubling of femtosecond pulses in thick nonlinear crystals with different temporal and spatial walk-off parameters IEEE Photonics Journal 8, 1-13 (2016)
- Hollow Gaussian beam generation through nonlinear interaction of photons with orbital angular momentum Scientific Reports 6, 32464 (2016)
- Ultrafast Airy beam optical parametric oscillator Scientific Reports 6, 30701 (2016)
- Ultrafast optical vortex beam generation in the ultraviolet Optics Letters 41, 2715-2718 (2016)
- Airy beam optical parametric oscillator Scientific Reports 6, 25245 (2016)
- Efficient nonlinear generation of high power, higher order, ultrafast perfect vortices in green Optics Letters 41, 1348-1351 (2016)
- Generation of perfect vortex of variable size and its effect in angular spectrum of the down-converted photons Scientific Reports 6, 21877 (2016)
- High-power, high-repetition-rate, Yb-fiber laser based femtosecond source at 355 nm Optics Letters 40, 4269-4272 (2015)
- Frequency-doubling characteristics of high-power, ultrafast phase singular optical beams Optics Letters 40, 2614-2617 (2015)
- All-periodically poled, high-power, continuous-wave, single-frequency tunable UV source Optics Letters 40, 33-36 (2015)
- Violation of Bell's inequality for phase-singular beams Physical Review A 92, 023822 (2015)
- Three-particle hyper-entanglement: teleportation and quantum key distribution Quantum Information Processing 14, 3813-3826 (2015)
- Type-I frequency-doubling characteristics of high-power, ultrafast fiber laser in thick BIBO crystal Optics Letters 39, 5419-5422 (2014)
- High-power, continuous-wave, solid-state, single-frequency, tunable source for the ultraviolet Optics Letters 39, 3410-3413 (2014)
- Yb-fiber-laser-pumped, high-repetition-rate picosecond optical parametric oscillator tunable in the ultraviolet Optics Express 22, 11476-11487 (2014)
- Spatial distribution of spontaneous parametric down-converted photons for higher order optical vortices Optics Communications 326, 64-69 (2014)
- Breakthroughs in Photonics 2012: Breakthroughs in Optical Parametric Oscillators IEEE Photonics Journal 5, 0700105 (2013)
- Continuous-wave, two-crystal, singly-resonant optical parametric oscillator: Theory and experiment Optics Express 21, 9520-9540 (2013)
- Frequency-modulation-mode-locked optical parametric oscillator Optics Letters 37, 115-117 (2012)
- Single-frequency, high-power, continuous-wave fiber-laser-pumped Ti:sapphire laser Applied Optics 51, 15-20 (2012)
- High-power, continuous-wave Ti:sapphire laser pumped by fiber-laser green source at 532 nm Optics and Lasers in Engineering 50, 215-219 (2012)
- Dual-wavelength, two-crystal, continuous-wave optical parametric oscillator Optics Letters 36, 3033-3035 (2011)
- High-efficiency, multicrystal, single-pass, continuous-wave second harmonic generation Optics Express 19, 11152-11169 (2011)
- Fiber-laser-based green-pumped continuous-wave singly-resonant optical parametric oscillator Laser Physics 21, 782-789 (2011)
- Multicrystal, continuous-wave, single-pass second-harmonic generation with 56% efficiency Optics Letters 35, 3513-3515 (2010)
- Optimally-output-coupled, 17.5 W, fiber-laser-pumped continuous-wave optical parametric oscillator Applied Physics B 102, 31-35 (2010)
- High-power, continuous-wave, optical parametric oscillator pumped by an optically pumped semiconductor laser at 532 nm Optics Letters 35, 1986-1988 (2010)
- Continuous-wave optical parametric oscillator pumped by a fiber laser green source at 532 nm Optics Letters 34, 2255-2257 (2009)
- Broadband, high-power, continuous-wave, mid-infrared source using extended phase-matching bandwidth in MgO:PPLN Optics Letters 34, 3836-3838 (2009)
- Stable, 9.6 W, continuous-wave, single-frequency, fiber-based green source at 532 nm Optics Letters 34, 1561-1563 (2009)
- High-power, single-frequency, continuous-wave second-harmonic-generation of ytterbium fiber laser in PPKTP and MgO:sPPLT Optics Express 17, 13711-13726 (2009)
- High-power, continuous-wave, second-harmonic generation at 532 nm in periodically poled KTiOPO4 Optics Letters 33, 2955-2957 (2008)
- Continuous-wave, single-frequency, solid-state blue source for the 425-489 nm spectral range Optics Letters 33, 1228-1230 (2008)
- Continuous-wave singly-resonant optical parametric oscillator with resonant wave coupling Optics Express 16, 6883-6888 (2008)
- 1.59 W, single-frequency, continuous-wave optical parametric oscillator based on MgO:sPPLT Optics Letters 32, 2623-2625 (2007)
- High-power, continuous-wave, singly resonant optical parametric oscillator based on MgO:sPPLT Optics Letters 32, 400-402 (2007)
- Growth of urea doped benzophenone single crystal for nonlinear optical applications Optical Materials 28, 324-330 (2006)
- Realization of inverse saturable absorption by intracavity third-harmonic generation for efficient nonlinear mirror mode-locking Applied Physics Letters 86, 151105 (2005)
- Diode array pumped, non-linear mirror Q-switched and mode-locked Nd:YVO4 laser - a good tool for powder SHG measurement Pramana 63, 1003-1010 (2004)
Complete List of Invited Talks & Keynotes
- Tutorial on basics of quantum communication Short course on Free-space Quantum Communication, Physical Research Laboratory, CSSTEAP Program (July 27–31, 2026)
- Beyond Narendrapur: Options and Futures Panel discussion, Physics Dept., Narendrapur Ramakrishna Mission Residential College, WB (July 4, 2026)
- Quantum Communication Popular Lecture, Crimson Cup Cafe, Ahmedabad (June 13, 2026)
- Quantum sensing using a high-brightness heralded single-photon source Optica Webinar, hosted by Holography and Diffractive Optics Group, Denmark Technical University (DTU) (May 5, 2026)
- Understanding quantum communication and its use FDC, I-HUB, Ahmedabad, Gujarat, India (April 24, 2026)
- Quantum communication: From principle to practice Workshop on Quantum Technologies, Ganpat University, Mehsana, Gujarat (March 13–14, 2026)
- Generation of high repetition rate ultrafast optical radiation using optical parametric oscillators Ultrafast Sciences (UFS 2025), IIT Hyderabad, India (November 13–15, 2025)
- Geometric phase and its application in classical and quantum optics International Conference on Nonlinear Optics and Nanophotonics (ICNNFT), IISER Bhopal (July 9–12, 2025)
- Spatial structured optical beams and their information science applications Workshop on Information Optics (WIO), ICFO, Barcelona, Spain (June 30 – July 4, 2025)
- Quantum sensing using Hong-Ou-Mandel interferometry of single photon Photonics for Energy, Sensing and Education (PESE-2025), IIT Gandhinagar (January 16–17, 2025)
- Quantum sensing using Hong-Ou-Mandel interferometry International Conference on Emerging Trends in Optical Technologies (ETOT-I), SRM University (January 2–4, 2025)
- Development of quantum sources and their applications Photonics 2024, IIT Kharagpur, India (December 12–15, 2024)
- Spatial structured heralded single photons XLVII OSI Symposium on Advances in Optics and Photonics Instrumentation (OPTOIn-2024), CSIR-CSIO Chandigarh (October 23–25, 2024)
- Quantum imaging of biological sample using Hong-Ou-Mandel interferometry BRICS Workshop on Biophotonics - 2024, MAHE, Manipal, India (October 3–5, 2024)
- Classical and quantum optics experiments using spatial structured beams Summer School on Optics and Photonics (SOP 24), IISc Bangalore (July 8–12, 2024)
- Quantum sensing using Hong-Ou-Mandel interferometer Workshop 4: Space Quantum Technologies (INSQT), Physical Research Laboratory, Ahmedabad (January 20–22, 2024)
- Full Poincare beam: generation, characterization, and applications to represent Hilbert Hotel paradox SPIE Photonics West, San Francisco, USA (January 27 – February 1, 2024)
- Structured beams for the experimental realization of Hilbert Hotel paradox International Conference on Optics, Photonics and Quantum Information (OPTIQ-2023), CUSAT, Kochi (December 11–13, 2023)
- Quantum sensing using high brightness heralded single photon source Quantum Information Processing and Applications (QIPA-2023), HRI, Prayagraj (December 4–10, 2023)
- Full Poincare beams: realization of Hilbert Hotel paradox Physics Seminar, IIT Delhi (November 6, 2023)
- Spatial structured optical beams: Linear and nonlinear optical studies ICFO-TIFRH International School on Frontiers of Light, TIFR-Hyderabad (October 25–27, 2023)
- Robust, bright photon sources for quantum communication and sensing Physics Colloquium, IIT Madras (September 13, 2023)
- Hong-Ou-Mandel interferometry based quantum sensor Photonics, IISc Bangalore (July 5–8, 2023)
- Structured optical beams for experimental implementation of Hilbert's Hotel paradox International Day of Light Celebration, IIT Ropar (May 16, 2023)
- Quantum sensing using Hong-Ou-Mandel Interferometer Summer School on Quantum Information and Quantum Technology (QIQT-2023), IISER Kolkata (May 8 – June 15, 2023)
- Hilbert hotel paradox using structured beams Photonics for Health, Atmosphere, Security, and Education (PHASE 2023), IIT Gandhinagar (March 30–31, 2023)
- Nonlinear interaction and the generation of structured beams Structured Light and Spin-Orbit Photonics, ICTS Bangalore (Nov 29 – Dec 2, 2022)
- Bright quantum source for quantum sensing Conference on Optics, Photonics, and Quantum Optics (COPaQ-2022), IIT Roorkee (November 10–13, 2022)
- Entangled photon source for satellite-based quantum communication Summer School on Quantum Information and Quantum Technology (QIQT-2022), IISER Kolkata (June 1–4, 2022)
- Are we ready with the indigenous entangled photon source for Indian space-based quantum technologies? Space Quantum Frontiers, Space Applications Centre (SAC/ISRO), Ahmedabad (May 19, 2022)
- Quantum key distribution: Principle to practice Ahmedabad University (March 23, 2022)
- Satellite Based Quantum Science & Experiments DTDI Technology Conclave, ISRO Headquarters, Bangalore (November 22–26, 2021)
- Development of entangled photon sources for future space-based experiments 44th Annual Symposium of OSI, Frontiers in Optics and Photonics (FOP21), IIT Delhi (September 24–27, 2021)
- Nonlinear effects of structured beams in classical and quantum optics experiments SPIE, OSA and OSI Student Chapter Webinar, University of Calcutta (September 12, 2021)
- Structured beam optical parametric oscillator based mid-IR sources Student Conference on Photonics and Quantum Technology (SCPQT), NISER Bhubaneswar (February 24–26, 2021)
- Orbital angular momentum transfer in classical and quantum optics experiments OSA High-brightness Sources and Light-driven Interactions Congress (November 16–20, 2020)
- Spatial structured optical beams SRM Institute of Science and Technology, Chennai (May 16, 2020)
- Contemporary Optics at Physical Research Laboratory: Structured optical beams Symposium on Intense Laser Application and Innovation, TIFR Hyderabad (January 27–29, 2020)
- Classical and quantum implementation of structured optical beams 107th Indian Science Congress, UAS Bangalore (January 3–7, 2020)
- High brightness entangled photon source for quantum communication International Symposium on Quantum Information Technology (ISQIT 2019), Pune (December 2–5, 2019)
- Structured optical beams Contemporary Trends in Optics 2019, IISER Kolkata (May 20–23, 2019)
- Nonlinear generation of structured optical beams Facets of Photonics- 2018, IISER Pune (December 24–26, 2018)
- Structured beams coherent radiation and their applications Recent Advances in Photonics, Manipal University, Karnataka (September 22, 2018)
- Nonlinear interaction of structured beams Workshop on Experimental Techniques in Physics, Institute of Advanced Research (IAR), Gandhinagar (June 4–14, 2018)
- High repetition rate, ultrafast parametric sources of structured beams Ultrafast Science 2017 (UFS-2017), University of Hyderabad (November 2–4, 2017)
- ICO/ICTP Gallieno Denardo Award Lecture Winter College on Optics, ICTP Trieste, Italy (February 2017)
- Nonlinear frequency conversion of structured beams and Airy beam optical parametric oscillator SPIE Photonics West, San Francisco, USA (Jan 28 – Feb 2, 2017)
- Structured beam parametric sources and optical parametric oscillators 25th DAE BRNS National Laser Symposium (NLS-25), KIIT University, Bhubaneswar (December 20–23, 2016)
- Structured laser beams and novel applications 7th EPS-QEOD EUROPHOTON Conference, Vienna, Austria (August 21–26, 2016)
- Structured beam optical parametric oscillators Recent Advances in Optical Sciences-II, School of Physics, University of Hyderabad (May 6–7, 2016)