Felão Luiz H V, Martin Roberta I, Martinez Guilherme A, Sakamoto João M S, Teixeira Marcelo C M, Kitano Cláudio
Opt Lett. 2022 Aug 1;47(15):3852-3855. doi: 10.1364/OL.465783.
A passive interferometry phase detection method is presented, which emulates the closed-loop high gain approach technique. This method comprises an all-digital closed-loop observer based on the variable structure and sliding modes nonlinear control theory, able to demodulate the phase of an open-loop feedback-free interferometer hardware. A proof-of-concept experiment is conducted by measuring complex displacements (module and angle) generated by a piezoelectric actuator. The results show that this method simplifies the optical hardware while providing features such as direct detection of the optical phase, increase of the dynamic range, high robustness, and dismissing of the feedback phase modulator and reset circuits.
提出了一种无源干涉测量相位检测方法，该方法模拟了闭环高增益逼近技术。该方法包括一个基于变结构和滑模非线性控制理论的全数字闭环观测器，能够对开环无反馈干涉仪硬件的相位进行解调。通过测量压电致动器产生的复位移（模量和角度）进行了概念验证实验。结果表明，该方法简化了光学硬件，同时提供了诸如直接检测光学相位、增加动态范围、高鲁棒性以及无需反馈相位调制器和复位电路等特性。
