| PhD Seminar

Name of the Speaker: Ms. Mrudula K (EE19D017)
Guide: Dr. Deepa Venkitesh
Venue: ESB-244 (Seminar Hall)
Date/Time: 31st July 2025(Thursday), 2 PM
Title: On-demand phase conjugators for fiber optic communication systems

Abstract :

By 2030, global internet usage is projected to exceed 7.5 billion users, leading to a substantial surge in demand for high-speed data transmission [cybersecurityventures.com]. Fiber optic communication systems, which serve as the backbone of the modern internet and mobile infrastructure, must accommodate increasing bandwidth requirements across access, metro, and long-haul networks. These demands are met using techniques such as wavelength division multiplexing (WDM) and advanced modulation formats that encode data using the amplitude, phase, and polarization of the optical carrier. While Erbium-doped fiber amplifiers (EDFAs) dominate amplification in C- and L-bands, semiconductor optical amplifiers (SOAs) offer compact, wideband alternatives due to their tunable gain properties. Despite their limitations, SOAs have gained renewed interest through improved design.

Optical phase conjugators (OPCs) offer a promising solution for mitigating fiber nonlinearities and dispersion by performing mid-span spectral inversion (MSSI), which reverses these effects from the first half of the link using a nonlinear medium for conjugate signal generation.

In this seminar, we explore the dual role of SOAs as amplifiers and nonlinear media for phase conjugation. We present a prototype of an SOA-based, on-demand optical phase conjugator capable of switching between amplifier and conjugator modes. This integrated module enables all-optical compensation of fiber impairments via MSSI while also reducing the complexity of digital signal processing (DSP) at the receiver. Moreover, it provides amplification when required, positioning it as a versatile and practical solution for future optical network deployment.