Publications by authors named "Muralekrishnan Ramakrishnan"
Article Synopsis
- Performing pattern recognition in the optical domain can offer benefits like high-speed operation and the ability to adjust and scale based on optical wave properties.
- This study combines optical correlation with optical biasing to achieve efficient QPSK pattern recognition using direct detection, eliminating the need for complex coherent detection.
- The experimental results show successful error-free recognition of multiple QPSK patterns over 3072 symbols at different baud rates, indicating effective performance with specific power thresholding values.
Compared to its electronic counterpart, optically performed matrix convolution can accommodate phase-encoded data at high rates while avoiding optical-to-electronic-to-optical (OEO) conversions. We experimentally demonstrate a reconfigurable matrix convolution of quadrature phase-shift keying (QPSK)-encoded input data. The two-dimensional (2-D) input data is serialized, and its time-shifted replicas are generated.
View Article and Find Full Text PDFIn this paper, we experimentally demonstrate an 8-Gbit/s quadrature-phase-shift-keying (QPSK) coherent underwater wireless optical communication (UWOC) link under scattering conditions at 532 nm. At the transmitter, we generate the 532-nm QPSK signal using second-harmonic generation (SHG), where the 1064-nm signal modulated with four phase levels of an 8-phase-shift-keying (8-PSK) format is phase doubled to produce the 532-nm QPSK signal. To enhance the receiver sensitivity, we utilize a local oscillator (LO) at the receiver from an independent laser source.
View Article and Find Full Text PDFArticle Synopsis
- * Researchers successfully demonstrate an optically-assisted method for averaging two 4-phase-encoded data streams at high rates of 10 and 20-Gbaud, resulting in a 7-phase-encoded output.
- * The process involves three key stages: phase encoding with an optical modulator, summation using nonlinear fiber, and multicast through a lithium niobate waveguide, with the final output showing increased error vector magnitudes and optical signal-to-noise ratio penalties.