Polarization for Optical Frequency Analysis and Optical Sensing Applications

Tunable diode laser spectroscopy (TDLS) systems and coherent distributed optical sensing systems, such as frequency modulated continuous wave Lidar, optical coherence tomography, and optical frequency domain reflectometer, generally require a frequency tunable laser scanning at high speed. For TDLS and coherent distributed sensing applications, it is important to know the following transient characteristics of the tunable lasers: the frequency tuning rate, nonlinearity, range, and repeatability, in addition to the power variation and frequency wiggle during each scan. Polarization analysis is generally not associated with obtaining optical spectral information by conventional wisdom. Gyroscopes are essential for fully autonomous vehicle control. The electrical current sensors made with optical fibers are particularly attractive for the monitoring, control, and protection of substations and power distribution systems in smart grid. Accuracy, sensitivity, dynamic range, and environmental stability are the main performance indicators for the fiber optic current sensors.