A Preliminary Study on Non Contact Thermal Monitoring of Microwave Photonic Systems

Microwave photonic systems are more susceptible to thermal fluctuations due tothermo-optic effect. In order to stabilize the performance of photonic components, thermal monitoringis achieved by using thermistors placed at any arbitrary location along the component. This workpresents non contact thermography of a fully functional microwave photonic system. The temperatureprofile of printed circuit board (PCB) and photonic integrated circuit (PIC) is obtained using FlukeFLIR (A65) camera. We performed Otsu’s thresholding to segment heat centers located across PCB aswell as PIC. The infrared and visible cameras used in this work have different field of view, therefore,after applying morphological methods, we performed image registration to synchronize both visibleand thermal images. We demonstrate this method on the circuit board with active electrical/photonicelements and were able to observe thermal profile of these components

All-Optical Flip-Flops Based on Semiconductor Technologies

Non

Machine Learning Techniques to Mitigate Nonlinear Phase Noise in Moderate Baud Rate Optical Communication Systems

Nonlinear phase noise (NLPN) is the most common impairment that degrades the performance of radio-over-fiber networks. The effect of NLPN in the constellation diagram consists of a shape distortion of symbols that increases the symbol error rate due to symbol overlapping when using a conventional demodulation grid. Symbol shape characterization was obtained experimentally at a moderate baud rate (250 MBd) for constellations impaired by phase noise due to a mismatch between the optical carrier and the transmitted radio frequency signal. Machine learning algorithms have become a powerful tool to perform monitoring and to identify and mitigate distortions introduced in both the electrical and optical domains. Clustering-based demodulation assisted with Voronoi contours enables the definition of non-Gaussian boundaries to provide flexible demodulation of 16-QAM and 4+12 PSK modulation formats. Phase-offset and in-phase and quadrature imbalance may be detected on the received constellation and compensated by applying thresholding boundaries obtained from impairment characterization through statistical analysis. Experimental results show increased tolerance to the optical signal-to-noise ratio (OSNR) obtained from clustering methods based on k-means and fuzzy c-means Gustafson-Kessel algorithms. Improvements of 3.2 dB for 16-QAM, and 1.4 dB for 4+12 PSK in the OSNR scale as a function of the bit error rate are obtained without requiring additional compensation algorithms