Phase-shifting interferometry with equal phase steps by use of a frequency-tunable diode laser and a Fabry-Perot cavity.
A phase-shifting interferometry (PSI) with equal phase steps by use of a frequency-tunable diode laser and a Fabry-Perot cavity is proposed for the Carré algorithm. The measurement accuracy of the Carré algorithm depends on the equality of the phase steps. Using the Fabry-Perot cavity as a highly stable optical frequency reference, a high degree of phase step equality can be realized in PSI with an optical frequency shift. Our experimental scheme realizes an optical frequency step equality higher than 5.1 x 10(-5) and a measurement repeatability of lambda/800.
Bitou
Youichi
Y
National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 3, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan. y-bitou@aist.go.jp
Inaba
Hajime
H
Hong
Feng-Lei
FL
Takatsuji
Toshiyuki
T
Onae
Atsushi
A