Abstract
The phase noise affecting the beat photocurrent produced by coherent detection of a single-frequency laser field with a time-delayed and frequency-shifted image of itself in a heterodyne two-wave interferometric system using a single-mode optical fiber is investigated as a function of source spectrum and phase-decorrelation time under the assumptions of quantum laser phase noise and high-local-oscillation level. The influence on the photocurrent spectrum of partial correlation between detected fields is pointed out. These calculations are an extension of a previously reported high-resolution spectroscopic method and account for the phase-noise limitation in unbalanced heterodyne fiber sensors and heterodyne-transmission receivers with an optical reference wave generated from the received signal. An experimental study is reported consisting of a Mach–Zender-type interferometer employing a single-frequency amplitude-stabilized laser, an acousto-optical single-side-band modulator for frequency shifting one of the arms, and several lengths of single-mode optical fiber to decorrelate the detected fields partially. Results are found to be in good agreement with theory.
© 1982 Optical Society of America
Full Article | PDF ArticleMore Like This
Kazuo Hotate, Naohiko Okuma, Minoru Higashiguchi, and Noboru Niwa
Opt. Lett. 7(7) 331-333 (1982)
Yoshihiro Ohtsuka
Appl. Opt. 21(23) 4316-4320 (1982)
Toshimitsu Musha, Jun-ichi Kamimura, and Masataka Nakazawa
Appl. Opt. 21(4) 694-698 (1982)