Disturbance-free phase-shifting laser diode interferometer using adaptive feedback control.
A feedback-control-equipped phase-shifting laser diode interferometer that eliminates external disturbance is proposed. The feedback loop is stabilized by adaptive control of the polarity of the interference signal. Conventional phase-shifting interferometry can be used with the feedback control, resulting in simplified signal processing and accurate measurement. Several experiments confirm the stability of the feedback control with a measurement repeatability of 1.8 nm.
Suzuki
Takamasa
T
Niigata University, Faculty of Engineering, 8050 Ikarashi 2, Niigata 950-2181, Japan. takamasa@eng.niigata-u.ac.jp
Takahashi
Tsutomu
T
Sasaki
Osami
O