Low-Noise Low-Delay Digital Signal Processor for Resonant Micro Optic Gyro

• Published in: IEEE photonics technology letters 2013-01, Vol.25 (2), p.198-201
• Main Authors: Ma, Huilian, Wang, Wenyi, Ren, Yang, Jin, Zhonghe
• Format: Article
• Language: English
• Subjects: Bandwidth; Digital signal processor; Noise; Optical fibers; Optical ring resonators; Resonant frequency; resonant micro optic gyro (RMOG); silica waveguide ring resonator
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2012.2233727

A low-noise low-delay digital signal processor is constructed on a single field-programmable gate array. An equivalent input noise as low as 3.752 nV/√Hz is demonstrated for the digital signal processor, which can detect an equivalent Sagnac effect of 0.003°/s in a resonant micro optic gyro (RMOG) with a 2.5-cm diameter ring resonator. With the processing time reduced from hundreds of seconds to 1.1 μs , this processor significantly increases the loop gain of the feedback loop and reduces the reciprocal noise in the RMOG. Owing to the fast speed of this processor, the lock-in frequency accuracy is reduced to 0.78 Hz (1σ), which is equivalent to a rotation rate of 0.004°/s. Relationship between this digitalized RMOG output signal and angular rate is obtained from ±0.25°/s to ±400°/s. The standard deviation of the residuals between RMOG output results and linear fit curve is 0.0236°/s.