Raktim Haldar was born in Kolkata, India. He is currently an assistant professor at the Department of Electronics and Communication Engineering, School of Electrical and Computational Sciences (SECs), Indian Institute of Technology Bhubaneswar (IITBBS), Odisha, India. He is also the chair of Optical Metrology Technical Group, Optica (formerly OSA) since 2024.

His present research goal is to bridge the gap between integrated photonics and fundamental physics at the nanoscale. Raktim’s future goal is to develop indigenous experimental quantum photonic technology facilities. His research interests include integrated photonics, fiber optics and optoelectronics, nonlinear optics, integrated quantum photonic technologies, quantum information, quantum neural network, etc.

Raktim was an invited speaker in several conferences and Institutes worldwide including Cavendish Laboratory, University Of Cambridge (UK), IITs, NITs, Lamar University (USA), tcg Crest, SPIE Photonics West, SPIE Europe, 11th Humboldt Award winning ceremony on quantum technologies to name a few. He was also invited to attend Comlab#7 and #9 organized by the Alexander von Humboldt (AvH) Foundation and International Journalist Forum for his contributions to science communication.

Previously, he was a postdoctoral researcher at Leibniz Universität Hannover, Germany since 2020, and an AvH Fellow at the same place since 2021. Raktim’s postdoctoral research was focused on discrete-variable (DV) quantum photonic systems. Within that period (in 2022), briefly, he was a visiting scientist at Paris Centre for Quantum Computing, Sorbonne University, France to work on quantum cryptography. Raktim obtained his Ph.D. from the E&ECE Department, Indian Institute of Technology Kharagpur in 2019. During his Ph.D. tenure, in 2018, Raktim was a Raman Charpak Fellow at C2N/CNRS, University Paris-Saclay, France and performed experimental studies on continuous-variable (CV) quantum photonic systems. He received M. Tech. degree from the same department with a specialization in RF & Microwave Engineering in 2013.

Raktim has authored and co-authored about 25 peer-reviewed journals and 40 international conferences. He is also a regular reviewer of several prestigious journals, e.g., Nature Photonics, Nature Communications, Scientific Reports, APS journals like Phys. Rev. Lett., Phys. Rev. Research, Phys. Rev. X., etc., and many Optica, IEEE, SPIE, and MDPI journals. Being a student member and eventually the president of the IITKGP Optical Society of America (OSA) student chapter he was actively involved in various activities since 2015, including organizing Photonics 2014 and IONS 2014. He is a lifetime member of SPIE and early career professional member of Optica, and IEEE.

Raktim is a painter, photographer, and science enthusiast. He enjoys writing popular science articles, stories, and columns in Bengali and English newspapers and magazines.

1) At IIT Bhubaneswar (IITBBS), India: 

Spring 2026: 

(i) Introduction to Signal Processing (EC2L008), (ii) Digital Electronics and Microprocessor laboratory (EC2P006)

Autumn 2025: 

 (i) Basic Electronics (EC2L005), (ii) Basic Electronics laboratory (EC2P007), (iii) Introduction to Electronics laboratory (EC2P001), (iv) Project Seminar (EC2S001)

Spring 2025: 

 (i) Introduction to Signal Processing (EC2L008), (ii) Digital Electronics and Microprocessor laboratory (EC2P006)

2) At Leibniz University Hannover (LUH), Germany: 

Spring and Autumn 2024 and 2023: 

(i) Applied Quantum Photonic Technologies (principal course instructor: Prof. Dr. Michael Kues)

3) At IIT Kharagpur (IITKGP), India, as a teaching assistant: 

Spring 2019

(i) Nonlinear optics and integrated photonics (principal course instructor: Prof. Basudev Lahiri)

Spring 2017

(i) Basic Electronics (Theory)

Spring 2016 

(i) Basic Electronics Laboratory (EC29001)

Autumn 2015

(i) Optical Communication Systems (EC60023) (principal course instructor: Prof. Shailendra K. Varshney)

Spring and Autumn 2012 

(i) Advances in Digital Satellite Communications (EC60126) (principal course instructor: Prof. Kalyan Bandhopadhyay), (ii) RF Network and Designing Laboratory (EC69012) (principal course instructor: Prof. Arijit De), (iii) Satellite Communications Systems (EC60101) (principal course instructor: Prof. Kalyan Bandhopadhyay), (iv) RF and Microwave Circuits Laboratory (EC69019) (principal course instructor: Prof. Ramesh Garg)

Thesis Guided (till April 2026)

A. Thesis guidance as a supervisor:

I. Ph.D. thesis:

1. Ms. Jayita Manna (Roll No: A25EC09008)

Brief Biography:

Ms. Jayita Manna is currently a Ph.D scholar in the Department of Electronics and Communication Engineering at the Indian Institute of Technology Bhubaneswar. She is originally from the Paschim Medinipur district of West Bengal. Jayita completed my M. Tech. in Applied Electronics and Instrumentation Engineering from the Heritage Institute of Technology, Kolkata, where she graduated as the gold medallist of her department. She obtained her B.Tech degree from the College of Engineering and Management, Kolaghat. Jayita completed her secondary education at Radhakantapur High School, where she secured first rank in her batch, and her higher secondary education at Sonakhali High School. Jayita’s research interests include optoelectronics, photonics, and semiconductor devices. She is particularly interested in exploring advanced materials and device architectures for next-generation electronic and photonic applications. Jayita is a student member of Optica.

Beyond academics, Ms. Jayita Manna is passionate about classical dance and enjoys painting, writing poetry, and composing articles in Bengali literature as forms of creative expression.

Contacts: a25ec09008@iitbbs.ac.in, jayita.mannanew300@gmail.com

II. Master’s thesis:

1. Mr. Soumen Mondal (Roll No: 24SP06013)

Brief Biography: 

Mr. Soumen Mondal is currently pursuing the M.Tech degree in Electronics and Communication Engineering at the Indian Institute of Technology Bhubaneswar, India. He joined the program
in July 2024 and is expected to graduate in May 2026 with a current CGPA of 8.06. He received his B.Tech degree in Electrical Engineering from Kalyani Government Engineering College, India, in 2021, with a CGPA of 8.29.His research interests include medical image analysis, deep learning, and foundation-model-based approaches for biomedical applications. More broadly, he is interested in structured prediction, and representation learning for complex, noisy, and data-limited environments. His work spans image segmentation, detection-guided learning, and prompt-based modelling across diverse applications such as Ultrasound, MRI imaging, pathology analysis, and vision-language systems. He is also interested in multimodal learning and the integration of large pre-trained models for robust and generalizable visual understanding. He has experience working with deep learning frameworks such as PyTorch and has explored architectures based on Vision Transformers, diffusion models, and large-scale pre-trained models, with applications ranging from medical imaging to 3D reconstruction and prompt-driven segmentation.

Beyond his academic pursuits, he has a keen interest in analytical problem-solving and emerging technologies in artificial intelligence. In his leisure time, he enjoys playing cricket and reading storybooks.

Contacts: He can be reached at 24sp06013@iitbbs.ac.in and soumenmon25@gmail.com.

2. Mr. Yogesh K. Mahawar (Roll No: 25SP06016)

Brief Biography: 

Mr. Yogesh Kumar Mahawar was born in Rajasthan, India, in 1998. He received his B.Tech degree in Electrical Engineering from Poornima College of Engineering (Rajasthan Technical University, Kota), Jaipur, India, in 2021. He is currently pursuing his M.Tech degree in Signal Processing and Communication Engineering at the Indian Institute of Technology Bhubaneswar (IITBBS), India. His current research focuses on PT-symmetric optical waveguides and topological configurations for optical communications, with emphasis on leveraging non-Hermitian photonic structures to enhance signal propagation, robustness, and system performance. His broader research interests include optical communications, photonics. He is particularly interested in bridging theoretical concepts with practical implementations in modern communication systems.

His hobbies include exploring emerging technologies, working with simulation tools, and solving engineering problems in communication and signal processing.

Contacts: He can be contacted at 25sp06016@iitbbs.ac.in, mahawaryogesh98@gmail.com.

1. Lynn Sader, Yassin Boussafa, Van Thuy Hoang, Raktim Haldar, Michael Kues, Benjamin Wetzel*, “Modulation instability control via evolutionarily optimized optical seeding,” Nanophotonics (De Gruyter) vol. 14, no. 16, pp. 2821-2833 (2025). Link: https://www.degruyterbrill.com/document/doi/10.1515/nanoph-2025-0070/html.  (IF: 6.5).

2023

1. Robert Johanning, Raktim Haldar, Jan Heine, Philip Rübeling, Anahita K. Kashi, and Michael Kues, “Generation and Tomographic Reconstruction of Non-maximally Entangled Frequency-bin Encoded Quantum State,” in preparation

2. Surajit Bose, Ihar Babushkin, Stefanus Wijaya, Alí Angulo, Philip Rübeling, Raktim Haldar, Debashri Ghosh, Uwe Morgner, Ayhan Demircan, and Michael Kues, “Time reflection of single-photon coherent states and the quantum-classical correspondence principle,” under review.

3. Raktim Haldar*, Hatam Mahmudlu, Robert Johanning, Albert van Rees, Jörn P. Epping, Klaus-J. Boller, and Michael Kues, “Fully on-chip laser-integrated quantum source of entangled photon states,” accepted to the Optics & Photonics News in the Year 2023 (by Optica). 

4. Alí M. Angulo M., Jan Heine, Samuel Durán, Hatam Mahmudlu, Raktim Haldar, Charalambos Klitis, Marc Sorel, and Michael Kues, “Enhanced generation of photon pairs by multi-frequency excitation of an SOI integrated nonlinear resonator,” Optics Letter, vol. 48, no. 21, pp. 5583-5586 (2023). DOI: https://doi.org/10.1364/OL.503909. (IF: 3.56).

5. Lynn Sader, Surajit Bose, Anahita Khodadad Kashi, Yassin Boussafa, Raktim Haldar, Romain Dauliat, Philippe Roy, Marc Fabert, Alessandro Tonello, Vincent Couderc, Michael Kues, Benjamin Wetzel, “A new approach of Dispersive Fourier-transform: Ultra-sensitive characterization of noise-driven nonlinear dynamics,” ACS Photonics (2023). DOI: : https://doi.org/10.1021/acsphotonics.3c00711  (IF: 7.077).

6. Hatam Mahmudlu†, Robert Johanning, Anahita K. Kashi, Albert van Rees, Jörn P. Epping, *Raktim Haldar†, Klaus-J. Boller, and Michael Kues, “Fully on-chip photonic turnkey quantum source for entangled qubit/qudit state generation,” Nature Photonics, vol. 17, pp. 518-524 (2023) (†These authors share equal contributions). DOI: https://doi.org/10.1038/s41566-023-01193-1. (IF: 39.728).

2022

1. *Raktim Haldar, Robert Johanning, Philip Rübeling, Anahita K. Kashi, Thomas Bækkegaard, Surajit Bose, Nikolaj T. Zinner, and Michael Kues, “Steering of Quantum Walks through the Coherent Control of High-dimensional Bi-photon Quantum Frequency Combs with Tunable State Entropies,” ArXiv link: https://doi.org/10.48550/arXiv.2210.06305 (2022).

2. Hatam Mahmudlu†, Robert Johanning, Anahita K. Kashi, Albert van Rees, Jörn P. Epping, *Raktim Haldar†, Klaus-J. Boller, and Michael Kues, “Fully on-chip photonic turnkey quantum source for entangled qubit/qudit state generation,” ArXiv Link: https://doi.org/10.48550/arXiv.2206.08715. (†These authors share equal contributions)

3. Anahita K. Kashi, Lynn Sader, Raktim Haldar, Benjamin Wetzel, Michael Kues, “Frequency-to-Time Mapping Technique for Direct Spectral Characterization of Biphoton States From Pulsed Spontaneous Parametric Processes,” Frontiers in Photonics, vol. 3, no. 834065, March 2022. DOI: 10.3389/fphot.2022.834065. (IF: 3.7).

2021

1. Raktim Haldar, Sandeep Ummethala, Rajat Sinha, Shailendra K. Varshney, “Nested non-concentric microring resonators with high-Q and large fabrication tolerance,” accepted in Journal of Optical Society of America B, vol. 38, Oct. 2021. DOI: https://doi.org/10.1364/JOSAB.430789. (IF: 2.106).

2019

1. Raktim Haldar, A. Roy, P. Mondal, V. Mishra, Shailendra K. Varshney, “Free-carrier Driven Kerr Frequency Comb in Optical Micro-cavities: Steady-state, bistability, self-pulsation, and modulation instability,” Phys. Rev. A, vol. 99, no. 033848, March 2019. DOI: https://doi.org/10.1103/PhysRevA.99.033848. (IF: 3.14).

2. Raktim Haldar, D. Barral, K. Bencheik, A. Levenson, N. Belabas, “Parallel Generation of Spatially Entangled Continuous Variable States in a 5×5 Periodically Poled LiNbO3 Waveguide Array,” under preparation in J. of Sel. Topics in Quantum. Electron.

2018

1. Raktim Haldar, A. Roy, P. Mondal, V. Mishra, Shailendra K. Varshney, “Generalized Mathematical Formalism Governing Free-carrier Driven Kerr Frequency Comb in Optical Micro-cavities,” arXiv Preprint arXiv: 1802.00391, 2018.

2. P. Mondal, R. Haldar, V. Mishra, S. K. Varshney, “All optical mode conversion and temperature sensing via transient-grating in step-index fiber,” IEEE Photonics Technology Letters, 30 (24), 2175-2178, Nov. 2018. DOI: 10.1109/LPT.2018.2879975. (IF: 2.486).

3. A. Roy, R. Haldar, S. K. Varshney, “Robust, Synchronous Optical Buffer and Logic Operation in Dual-pump Kerr Micro-resonator,” IEEE Journal of Lightwave Technology, vol. 36, no. 24, 5807-5814, Oct. 2018. DOI: 10.1109/JLT.2018.2878573. (IF: 4.439). 

4. Arkadev Roy, R. Haldar, and Shailendra K. Varshney, “Analytical Model of Dual-Pumped Kerr Micro Resonators for Variable Free Spectral Range and Composite Frequency Comb Generation,” IEEE/OSA Journal of Lightwave Technology, vol. 36, no. 12, pp. 2422-2429, 2018. DOI: 10.1109/JLT.2018.2812900. (IF: 4.439). 

5. V. Mishra, R. Haldar, P. Mondal, and S. K. Varshney, “Efficient all-optical transistor action in short-length multi-mode optical fibers,” IEEE Journal of Lightwave Technology, vol. 36, no.13, pp. 2582-2588, 2018. DOI: 10.1109/JLT.2018.2811805. (IF: 4.439). 

6. P. Mondal, N. Bhatia, V. Mishra, R. Haldar, S. K. Varshney, “Cascaded Raman and Intermodal Four-wave mixing in Conventional Non-Zero Dispersion Shifted Fiber For Versatile Ultra-Broadband Continuum Generation,” IEEE/OSA Journal of Lightwave Technology, vol. 36, no. 12, pp. 2351-2357, 2018. DOI: 10.1109/JLT.2018.2809914. (IF: 4.439). 

2017

1. V. Mishra, S. P. Singh, R. Haldar, P. Mondal and S. K. Varshney, “Intermodal nonlinear effects mediated optical event horizon in short-length multimode fiber,” Physical Review A, vol. 96, no. 013807, 2017. DOI: https://doi.org/10.1103/PhysRevA.96.013807. (IF: 3.14).

2016

1. Raktim Haldar, V. Mishra, A. Dutt, S. K. Varshney, “On-chip Broadband Ultra-Compact Directional Couplers and Polarization Splitters based on Off-centred and Non-Symmetric Slotted Si Wire Waveguides,” Journal of Optics, IOP Science, vol. 18, no. 10, 105801, September 2016. DOI: 10.1088/2040-8978/18/10/105801. (IF: 2.516). 

2. V. Mishra, S. P. Singh, R. Haldar, and S. K. Varshney, “Sub-Wavelength Dual Capillaries-Assisted Chalcogenide Optical Fibers: Unusual Modal Properties in Mid-IR (2-5 um) Spectral Range,” IEEE Journal of Selected Topics in Quantum Electronics, vol. 22, no. 2, p. 4401906, Mar-Apr, 2016. DOI: 10.1109/JSTQE.2015.2497335. (IF: 4.563). 

2015

1. G. T. Raja, R. Halder, and S. K. Varshney, “Numerical analysis of lasing characteristics in highly bend-compensated large-mode-area ytterbium-doped double-clad leakage channel fibers,” Applied Optics, vol. 54, no. 35, pp. 10314-10320, Dec. 10, 2015. DOI: https://doi.org/10.1364/AO.54.010314. (IF: 1.905). 

2014

1.  R. Haldar, Abhik D. Banik, and Shailendra K. Varshney, “Design of CMOS compatible and compact, thermally-compensated electro-optic modulator based on off-axis microring resonator for dense wavelength division multiplexing applications,” Opt. Express, vol. 22, no. 19, pp. 22411-22420, Sept. 2014. DOI: https://doi.org/10.1364/OE.22.022411. (IF: 3.833). 

2013

1. R. Haldar, S. Das, S. K. Varshney, “Theory and Design of Off-axis Microring resonators for on-chip photonics applications,” IEEE Journal of Lightwave Technology, vol. 31, no. 24, pp. 3976-3986 Dec. 2013. DOI: 10.1109/JLT.2013.2278552. (IF: 4.439).

2. Susobhan Das, R. Haldar and S. K. Varshney, “Triple-core Collinear and Non-Collinear Plasmonic Photonic Crystal Fiber Couplers,” Applied Optics (AO), vol. 52, no. 34, pp 8199-8204, Nov, 2013. DOI: https://doi.org/10.1364/AO.52.008199. (IF: 1.905). 

1. 23 Dec. 2024 – Till date: Assistant professor (grade – I) at Electronics and Communication Engineering, School of Electrical and Computer Sciences (SECs), Indian Institute of Technology Bhubaneswar (IIT Bhubaneswar), India.
2. 01 May 2023 – 22 Dec. 2024: Senior postdoctoral scientist at the Institute of Photonics (IOP), Leibniz University Hannover, Germany. Sponsored by: Flexible funds, Leibniz University Hannover, Germany (independent project).                                                                                                                                 
3. 01 May 2021 – 30 April 2023: Alexander von Humboldt fellow (AvH) (guest scientist) at Institute of Photonics (IOP), Leibniz University Hannover, Sponsored by: Alexander von Humboldt Foundation.       
4. 14 Sept. 2022 – 26 Sept. 2022: Visiting scientist at Univ. of Paris (Sorbonne Univ.) at the Paris Centre for Quantum Computing, Pierre and Marie Curie campus, Jussieu, Paris, France.
5. 01 Jan. 2020 – 30 April 2021: Postdoctoral researcher, at IOP, Leibniz University Hannover, Germany.
6. 23 Oct. 2019 – 21 Nov. 2019: Senior research fellow (SRF) at IIT Kharagpur. Sponsored by: ISRO and IIT Kharagpur.
7. 12 Mar. 2018 – 08 Aug. 2018: Raman Charpak Fellow (RCF) and  visiting researcher at CNRS/C2N, Marcoussis Campus, Univ. Paris-Saclay, Paris, France, Sponsored by: IFCPAR/CEFIPRA

1. Best paper award in IEEE Conference QCom(P), COMSNET 2024, Bangalore, India.
2. Elected as the leader of Optical Metrology Technical Group, Optica, for three years (2024-27).
3. Article selected as cover in OPN in the year 2023 for vol. 34 (2023).
4. Article selected as cover in ACS Photonics for vol. 10 (2023).
5. Received Flexible Funds 2023, a research grant provided by Leibniz University Hannover, Germany to conduct an independent project.
6. Selected for the prestigious Digital Communication Laboratory by the Humboldt Foundation.
7. Alexander von Humboldt Fellowship 2021 (postdoctoral research) on quantum neural network.
8. Raman-Charpak Travel grant to attend SPIE Photonics Europe 2018, Strasbourg, France,
9. Raman-Charpak Fellowship 2017-2018 to research Experimental Integrated Quantum Photonics/computation in CNRS/C2N, Marcoussis campus, Univ.   Paris- Saclay, France.
10. Article selected as cover in IEEE Journal of Lightwave Technology for vol. 36 (2018).
11. OSA Student travel grant to attend Student Leadership Conference (SLC), 2017.
12. DST-ITS travel grant 2017 from Indian Govt. to attend FiO/LS, in Washington DC.
13. International Commission for Optics (ICO) travel grant winner to attend ICO-24 (2017) at Tokyo, Japan.
14. Student travel grant/Full financial support to attend the best conference (CLEO Pacific Rim, 2017, Singapore) from IIT Kharagpur.
15. The article, “On-chip broadband ultra-compact optical couplers and polarization beam splitters based on off-centered and non-symmetric slotted Si-wire    waveguides,” is chosen among the ‘highlights of 2016’ on the category ‘Integrated Optics’ by IOP science.
16. OSA foundation student travel grant 2016 to attend IPR 2016, Vancouver, Canada.
17. MHRD Scholarship from Indian Govt. to pursue PhD (2014-2019).
18. MHRD Scholarship from Indian Govt. to pursue M.Tech. (2011-2013).

Talks/Lectures/upcoming events:

1. Invited talk on “Integrated Photonic Devices for Quantum Applications: From Communication to Neural Networks,” at Faculty Development Program and Student Workshop on Advanced Nanomaterials and Nanodevices for Electronic, Optoelectronic, and Photonic Applications, NIT Rourkela, Odisha, India (on 24th March 2026). (Poster below)

2. Invited talk on the quantum source at the Cavendish Laboratory, University of Cambridge, United Kingdom (on 3rd September 2024). (Images below)

3. Invited talk on the smart quantum optical systems at SPIE Europe 2024, Strasbourg, France. 

4. Invited talk on the quantum source at SPIE Photonics West 2024, San Francisco, California, USA. 

5. Invited as a delegate and a presenter by the 11th Alexander von Humboldt Award Winners’ Forum at Bonn (18-20 Oct. 2023) in ‘Quantum Science: from Foundations to Instrumentations.’

6. Invited talk on quantum photonic technologies at IEEE student chapter, Calcutta University.  (coming soon)

7. Invited talk (keynote) on the fully integrated quantum source in Symposium on Integrated Photonics and Quantum Optics: Young Researchers’ Colloquium 2023 organized by Centre for Quantum Engineering, Research and Education (CQuERE), TCG Crest. 

8.  Invited talk on the fully integrated quantum source at Humboldt Alumni Meet (Lab Talk) 2023. Link: https://vimeo.com/842378799?share=copy (video available here)

9. Invited talk on the fully integrated quantum source in CLEO Europe 2023 at Munich, Germany.

10. Invited talk on the quantum source at the European Conference on Integrated Optics (ECIO), 2023

11. Talk on SPIE Photonics West, San Francisco, California, 2023 on unidirectional quantum walk.

12. Invited talk on fully integrated quantum qudit source at Lamar Univ. Texas, USA, 2022.

13. Talk on the world’s first electrically-pumped laser-integrated fully on-chip quantum qudit source at FiO, Rochester NY, USA, Oct. 20, 2022. (video available). Link: https://youtu.be/WFuHCpvKazg (video below)

1.  Contributed presentation at CLEO-Europe-2021 on the quantum walk: Video link: https://seafile.cloud.uni-hannover.de/f/2fd6a479110a436f8187/ (video below)

2. Invited lecture on Optical & quantum communication at EC department, NIT Trichy, 2021

3. “Entropy of quantum frequency comb,” at PhoenixD, Leibniz Univ. Hannover, Jan 15, 2021

4. Popularizing quantum technologies within the industry (Webinar at In Time Tec, Bangalore)

5. Talk on Kerr Frequency Comb in ICEE, Bangalore, Nov. 18, 2018.

6. Talk on photonic-based sensors at FiO, Washington DC, USA, Sept. 20, 2017