Title :
Effect of laser-diode power change on optical heterodyne interferometry
Author :
Onodera, Ribun ; Ishii, Yukihiro ; Ohde, Nobuyuki ; Takahashi, Yoshitaka ; Yoshino, Toshihiko
Author_Institution :
Dept. of Electron., Univ. of Ind. Technol., Kanagawa, Japan
fDate :
4/1/1995 12:00:00 AM
Abstract :
A dynamic interferometer with a frequency-ramped laser diode (LD) has been constructed that is based on an optical heterodyne technique. Effect of LD power change on the optical heterodyne interferometry has been investigated theoretically and experimentally. A general formulation of the interferometry has been presented in which the demodulation scheme is analyzed in the frequency domain by Fourier-transforming a beat signal. Phase errors caused by the LD-power variation alter sinusoidally with the same period as the interference beat signal. The error can be eliminated by using an amplitude-stabilized, frequency-modulated laser diode source in the interferometer. The stabilization of the LD amplitude can be achieved by a feedback system with a superluminescent diode as an external light-power controller
Keywords :
Fourier transform optics; demodulation; frequency modulation; laser stability; light interferometers; measurement by laser beam; measurement errors; optical modulation; semiconductor lasers; superluminescent diodes; Fourier-transforming; LD amplitude stabilisation; LD-power variation; amplitude-stabilized frequency-modulated laser diode source; beat signal; demodulation scheme; dynamic interferometer; external light-power controller; feedback system; frequency domain; frequency-ramped laser diode; interference beat signal; laser-diode power change; optical heterodyne interferometry; optical heterodyne technique; phase errors; sinusoidally; superluminescent diode; Demodulation; Diode lasers; Frequency; Laser theory; Laser transitions; Optical feedback; Optical interferometry; Optical mixing; Power lasers; Signal analysis;
Journal_Title :
Lightwave Technology, Journal of
