Chinese Optics Letters, Volume. 16, Issue 8, 081201(2018)
Noise reduction and signal to noise ratio improvement in magneto-optical polarization rotation measurement
Fig. 1. Polarization rotation measurement system using Faraday modulator. P, polarizer; FM, Faraday modulator; C, rotation generating cell; A, analyzer; PD, photodetector; LIA, lock-in amplifier.
Fig. 2. Schematic of the Faraday modulation-based polarization rotation measurement setup using differential detection. P, polarizer; FM, Faraday modulator; NPBS, non-polarizing beam splitter; M, mirror; C, rotation generating cell; A1, A2, analyzers; PD1, PD2, photodetectors; LIA, lock-in amplifier; OSC, oscilloscope.
Fig. 3. Variation in the axial magnetic field of the solenoid coil of the Faraday modulator.
Fig. 4. Measurement of the Verdet constant of TGG magneto-optic glass using the differential measurement system.
Fig. 5. Noise spectra for a small polarization rotation angle using two measurement techniques. The black and red curves correspond to the single beam detection and the optical differential detection, respectively. The low-frequency performance was considerably improved with the optical differential detection method.
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Muhammad Basharat, Ming Ding, Yang Li, Hongwei Cai, Jiancheng Fang, "Noise reduction and signal to noise ratio improvement in magneto-optical polarization rotation measurement," Chin. Opt. Lett. 16, 081201 (2018)
Category: Instrumentation, measurement, and metrology
Received: Apr. 24, 2018
Accepted: Jun. 6, 2018
Published Online: Aug. 2, 2018
The Author Email: Ming Ding (mingding@buaa.edu.cn)