Phase-shifting interferometry with feedback control using heterodyne phase detection.
A phase-shifting interferometer with feedback control using heterodyne phase detection was developed. A composite heterodyne phase detection method for obtaining feedback signals was proposed. Interference fringe stabilization and accurate pi/2 phase shifts under micrometer-order vibrations were successfully demonstrated using a digital high-speed lock-in amplifier.
Bitou
Youichi
Y
National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central, Ibaraki, Japan. y-bitou@aist.go.jp