Optical Communication

Optical Communication is a cornerstone of modern information technology, enabling high-speed, high-capacity data transmission through the use of light waves, typically via fiber optic cables. This technology underpins global internet connectivity, telecommunication networks, and data center operations, offering unparalleled bandwidth, low signal attenuation, and immunity to electromagnetic interference.

At the Academy of Technology (AOT), research in optical communication focuses on both fundamental and applied aspects of photonics and fiber optics. Faculty and students work on designing advanced modulation formats, wavelength-division multiplexing (WDM) techniques, and optical amplification systems to maximize data throughput. Studies also explore nonlinear effects in optical fibers, signal processing algorithms for dispersion compensation, and integration of optical systems with emerging 5G and beyond-5G communication networks. Practical applications of AOT’s research extend to high-speed internet infrastructure, satellite communication links, and undersea cable systems that form the backbone of global information exchange. In industrial and defense sectors, optical communication ensures secure, high-capacity data transfer over long distances with minimal latency. Researchers are also exploring free-space optical communication for applications in space missions and remote sensing, enabling robust links where traditional wired connections are not feasible.

Looking ahead, AOT’s work in optical communication will emphasize integration with photonic integrated circuits (PICs), quantum communication protocols, and energy-efficient network designs. By advancing these technologies, AOT aims to contribute to the next generation of communication systems that will support exponential growth in global data demand. Through this research, the Academy of Technology continues to play a pivotal role in shaping the future of high-speed, reliable, and sustainable communication networks.

Researchers:

Prof. (Dr.) Abhijit Banrjee (ECE Department)
Dr. Jayjeet Sarkar (EEE Department)
Dr. Pinakpani Mukherjee (ECE Department)
Mr. Dipanjan De (ECE Department)

Projects:

Study to minimize the effect of Local Oscillator (LO) injection-pulling in Direct Conversion Transmitter (DCT) considering Optoelectronic Oscillator (OEO) as LO
Investigation of Pulling Behavior of RF Signal Driven Single-loop Optoelectronic Oscillator
Machine Learning-Based Optimization of Detection Thresholds for Crosstalk Mitigation in WDM Systems
The Effect of Graphene on Silica Based Periodic Optical Waveguides and Devices

Problem Description: A good quality Local Oscillator (LO) is a key component in a Direct Conversion Transmitter (DCT), which can generate and transmit radio frequency (RF) signals directly from the baseband frequencies. Low-phase noise RF signals with long-term frequency stability can be generated using an Optoelectronic oscillator (OEO), which is a potential device that can act as LO in DCT. Injection-pulling is a common phenomenon in DCT, where the injection of co-frequency modulating spurious tones originating from the DCT output signal often degrades the LO phase noise performance. It is highly important to study the deleterious effects of LO injection-pulling on the signal quality of both LO output signal and the DCT output signal, considering an OEO as LO in DCT.

Focus of Research:

To improve understanding of injection-pulling and injection-locking in connection with the Optoelectronic Oscillator (OEO) based Local Oscillator (LO) in Direct Conversion Transmitter (DCT) system.
To give quantitative estimates of phase noise degradation and spectral re-growth of the LO output signal and the DCT output RF signal when the LO is injection-pulled by the DCT output RF signal, considering non-constant envelope modulation of the DCT.
To provide a solution to mitigate the deleterious effects of LO injection-pulling on the transmit signal quality and to provide experimental data to optimize the performance of single-loop OEO-based LO in a DCT.

Publications:

A. Banerjee, and T. J. Hall, Simulation of optoelectronic oscillator injection locking, pulling & spiking phenomena Scientific Reports (Nature publishing group UK), vol. 14, no.1, pages 4332, Feb 2024. https://doi.org/10.1038/s41598-024-54777-4
M. Hasan, A. Banerjee, and T. J. Hall, Injection locking of optoelectronic oscillators with large delay, J. of Lightwave Technology (IEEE), vol. 40, no. 9, pp. 2754-2762, May 2022, https://doi:10.1109/JLT.2022.3148480
J. Sarkar, A. Banerjee, G. M. Pacheco, N. R. Das, Experimental Investigation on the Side Mode Injection Locking of a Single-loop OEO under RF Signal Injection, Analog Integrated Circuits and Signal Processing (Springer), vol. 118, pp. 539-552, Feb 2024. https://doi.org/10.1007/s10470-024-02262-3
A. Banerjee, L. A. D. de Britto and G. M. Pacheco, Study of the phase noise spectrum in RF injection-locked single-loop Optoelectronic Oscillators, Optical and Quantum Electronics (Springer), vol. 54, no. 60, 2022, https://doi.org/10.1007/s11082-021-03423-8
L. A. D. de Britto, J. Panasiewicz, G. M. Pacheco and A. Banerjee, Optoelectronic oscillator with dual loop in RF domain, Optical and Quantum Electronics (Springer), vol. 53, no. 521, July 2021, https://doi.org/10.1007/s11082-021-03128-y
A. Banerjee, L. A. D. de Britto and G. M. Pacheco, Study of mutual injection-pulling between two mutually-coupled single-loop optoelectronic oscillator, Optik (Elsevier), vol. 231, no. 166492, Apr. 2021, https://doi.org/10.1016/j.ijleo.2020.166495

Problem Description: A wide range of applications, including 5G wireless networks, have employed optoelectronic oscillators (OEOs) as local oscillators (LOs) to produce complex and single-frequency signals with minimal phase noise in the microwave, mm-wave, and terahertz (THz) bands. Numerous embedded components, including power amplifiers and OEOs, are used in radio frequency (RF) trans-receiver circuits in modern wireless communication systems. The nonlinearity of the OEO output around the OEO carrier frequency can result in harmonic components, and signal leakage through the substrate might combine with other OEOs to cause frequency pulling which is undesired. It is necessary to look into these crucial aspects of phase-locking phenomena and related frequency pulling effects in OEO caused by RF signal injection.

Focus of Research:

Despite substantial advances in OEOs, additional research is required to understand the OEO’s phase dynamical behaviour and frequency pull-in phenomena.

More research is needed, particularly on the transition from the fast-beat condition through the quasi-locked state and, finally, to the locked state.

Also the transient characteristic to estimate the phase and frequency settling behaviour of the OEO.
This research gap hinders our understanding of the fundamental mechanisms that regulate OEO behavior, which has crucial consequences for optoelectronic system design and optimization.

Publications:

Abhijit Banerjee, Larissa Aguiar Dantas de Britto, Jayjeet Sarkar, and Gefeson Mendes Pacheco, A Theoretical and Experimental Study of Injection Pulling in Phase-Locked Optoelectronic Oscillator under Radio Frequency Signal Injection, IETE Journal of Research 69, no. 5 (2023): 2941-2949. https://www.tandfonline.com/doi/abs/10.1080/03772063.2021.1908852
Abhijit Banerjee, Jayjeet Sarkar, Larissa Aguiar Dantas de Britto, Gefeson Mendes Pacheco, and Nikhil Ranjan Das, The transient behavior of single-loop optoelectronic oscillators under RF injection-locking, IEEE Journal of Quantum Electronics 56, no. 6 (2020): 1-13. https://ieeexplore.ieee.org/abstract/document/9171871
Jayjeet Sarkar, Larissa Aguiar Dantas de Britto, Abhijit Banerjee, Nikhil Ranjan Das, and Gefeson Mendes Pacheco, Frequency pulling in optoelectronic oscillator by RF signal injection, Optical and Quantum Electronics 52, no. 4 (2020): 214. https://link.springer.com/article/10.1007/s11082-020-02331-7
Jayjeet Sarkar, Abhijit Banerjee, and Nikhil Ranjan Das, A theoretical and experimental study of the frequency pulling phenomenon in a single-loop optoelectronic microwave oscillator due to RF signal injection, Optik 207 (2020): 164427. https://www.sciencedirect.com/science/article/abs/pii/S0030402620302618
Banerjee, Abhijit, Jayjeet Sarkar, and Baidyanath Biswas, Study of phase-locking of optoelectronic microwave oscillators considering amplitude perturbation, Optical and Quantum Electronics 51.6 (2019): 199. https://link.springer.com/article/10.1007/s11082-019-1900-2
Abhijit Banerjee, and Jayjeet Sarkar, Improved analytical model of phase-locking dynamics in unlocked-driven optoelectronic oscillators under RF injection locking, Optics Communications 437(2019):184-192. https://www.sciencedirect.com/science/article/abs/pii/S0030401818310939
Jayjeet Sarkar, Abhijit Banerjee, and Baidyanath Biswas, Analysis of frequency pulling phenomenon in an optoelectronic oscillator, Optical Engineering 57.6 (2018): 067102-067102. https://doi.org/10.1117/1.OE.57.6.067102
Abhijit Banerjee, Jayjeet Sarkar, Nikhil Ranjan Das, Baidyanath Biswas, Phase-locking dynamics in optoelectronic oscillator, Optics Communications, Volume 414, 2018, Pages 119-127, ISSN 0030-4018. https://doi.org/10.1016/j.optcom.2018.01.006

Problem Description: The work proposes a machine learning-based approach for real-time optimization of the optimal detection threshold (ODT) in WDM systems affected by linear and nonlinear crosstalk. By modeling a WDM receiver with a generalized crosstalk framework and using gradient descent with regression techniques, the method accurately estimates ODT without complex analytical computations. It correlates ODT with key parameters like interferer count, crosstalk level, and input power. The approach adapts to nonlinear scenarios via hybrid regression models. Validated through regression-based metrics, the solution enhances transmission quality and network resilience, offering scalable, intelligent threshold optimization for evolving optical networks.

Focus of Research:

Machine learning-based estimation of BER and associated system parameters
Optimization of detection thresholds using regression and gradient descent techniques

Publications:

P. P. Mukherjee, S. Sarkar, and N. R. Das, Analysis of SNR penalty in coherent WDM receiver system for detection of QPSK signal with component crosstalk, Annals of Telecommunications, 78, 577-584, 2023. https://doi.org/10.1007/s12243-023-00958-7

P. P. Mukherjee, S. Sarkar, and N. R. Das, Spectral efficiency and quantum limit of BPSK transmission in a WDM system in presence of multiple interferers, Photonic Network Communications, 42, 134–141, 2021. https://doi.org/10.1007/s11107-021-00945-9

P. P. Mukherjee, S. Sarkar, and N. R. Das, An approach for realistic estimation of BER due to signal-component crosstalk in a WDM receiver, Optik – International Journal for Light and Electron Optics, Volume 146, Pages 1-7, ISSN 0030-4026, 2017. https://doi.org/10.1016/j.ijleo.2017.07.066
G. Ghosh, M. Ghosh and P. Mukherjee, Bitcoin Price Analysis and Prediction Using DMA and LSTM, 2024 4th International Conference on Computer, Communication, Control & Information Technology (C3IT), Hooghly, India, 2024, pp. 1-6. https://ieeexplore.ieee.org/document/10829446

P. Mukherjee, D. Chakraborty and S. Sarkar, Impact of Component Crosstalk on Power Penalty of a WDM Receiver in QPSK Multiuser Optical Network, 2024 4th International Conference on Computer, Communication, Control & Information Technology (C3IT), Hooghly, India, 2024, pp. 1-5. https://ieeexplore.ieee.org/document/10829394

Book Chapters:

P. P. Mukherjee, S. Sarkar, and N. R. Das, Comparison of Power Penalty Due to Component, SRS, and FWM Crosstalk in a WDM Receiver, Advances in Computer, Communication and Control, Springer Singapore, 2019, eBook ISBN: 978-981-13-3122-0; Hardcover ISBN: 978-981-13-3121-3; Series ISSN: 2367-3370. https://link.springer.com/book/10.1007/978-981-13-3122-0

Student Projects:

Title: Bitcoin Price Analysis and Prediction Using DMA and LSTM
Students: Gourab Ghosh, Megha Ghosh
Supervisor: Dr. Pinakpani Mukherjee (ECE Department)
Year: 2024
Title: Leveraging Regression Analysis to Predict BER and Power Penalty in WDM Systems with SRS Crosstalk
Students: Bhumika Kar, Dayita Koley
Supervisor: Dr. Pinakpani Mukherjee (ECE Department)
Year: 2025

Problem Description: Our objective is to study the effect of graphene layers placed over a silicon waveguide grating for its dynamic filtering properties. By applying a suitable voltage to the grapheme layer, it is possible to have a tunable spectrum for Bragg waveguide grating. If we employ the same principle and keep the grating period Ʌ of the order of hundreds of microns, it is possible to have another class of longitudinal gratings known as Long Period Gratings.

Focus of Research:

Graphene intra and interband conductivity with Linear Response Theory in the infrared to visible wavelength.
How introduction of Graphene layer in silicon waveguides changes its reflection, transmission, and absorption properties.
Effect of Graphene in periodic optical waveguide structures, especially its band tailoring properties.

Publications:

Satyendra Pratap Singh and Dipanjan De, Dense and narrow stop-bands structure based on one dimensional photonic crystal filter for optical communication, International Journal of Engineering Science & Computing (IJESC), pp. 15212, Volume 7, Issue No. 10, October 2017.

Student Projects:

Title: 3-lead ECG design with instrumentation amplifier
Students: Tannisha Konar, Tushar Shil, Satwick Mukherjee, Subrata Paul, Tanmoy Ghosh, Vivek Kumar Puri
Supervisor: Dipanjan De (ECE Department)
Year: 2024-26
Title: Greenhouse gas sensor based on Sol-Gel technique and its conditioning by microcontroller
Students: Nikhil Deo Singh, Banisha Mallick, Priyanjali Mukherjee, Priyanshu Yadav, Kunal Das
Supervisor: Dipanjan De (ECE Department)
Year: 2024-26