arXiv subjects
Publications and source records attributed to Deepa Venkitesh.
We present a detailed analysis of the numerical modelling and evaluation of sub-systems in a Gaussian modulated CV-QKD system, incorporating non-ideal operations, and along with associated results.
We theoretically investigate the suitability of the selection of pump frequency ($ω_p$) with respect to the signal frequency ($ω_s$) for the best polarization insensitive phase conjugate generation through Bragg-scattering based four-wave mixing in nonlinear SOAs. We study the positive detuning ($ω_s>ω_p$) and negative detuning ($ω_s<ω_p)$ scenario for the inherent polarization transformation of conjugate generation at both the ports of SOA. Conjugate generation is desired to be through a unitary transformation for its utility in further digital signal processing, and we prove that only positive detuning conditions result in unitary transformation.
We report a novel technique to detect dynamic strain variations simultaneously at multiple locations. Our technique is based on Brillouin optical correlation domain analysis implemented through external phase modulation to generate multiple independently-accessible correlation peaks within the sensing fiber. Simulations are carried out to demonstrate the precise determination of Brillouin frequency shift (BFS) from multiple locations independently, and the corresponding results are validated through controlled experiments. Two correlation peaks are generated within a 1 km long fiber and their independent tunability is verified experimentally by mapping the spatial profile of the two correlations. We demonstrate the detection of dynamic strain variations up to 50 Hz (limited only by our test setup) at two locations, each with a spatial resolution of 6 m over 1.1 km long fiber.
We propose and verify the use of the power spectral density of the FM noise spectrum to study the phase noise relationship between the four-wave mixing components.