Title :
Phase noise reduction by self-phase locking in semiconductor lasers using phase conjugate feedback
Author :
Petersen, Lykke ; Gliese, Ulrik ; Nielsen, Torben Nørskov
Author_Institution :
Center for Broadband Telecommun., Tech. Univ. Denmark, Lyngby, Denmark
fDate :
11/1/1994 12:00:00 AM
Abstract :
A theoretical analysis of the behavior of the frequency/phase noise of semiconductor lasers with external phase conjugate feedback is presented. It is shown that the frequency noise is drastically reduced even for lasers with butt-coupled phase conjugate mirrors. In this laser system, the phase noise takes a finite-low value corresponding to a state of first-order self-phase locking of the laser. As a result, the spectral shape of the laser signal does not remain Lorentzian but collapses around the carrier to a delta function with a close to carrier noise level of less than -137 dBc/Hz. The total phase variance of this laser signal, in a 20 GHz noise bandwidth, is less than 0.002 rad2
Keywords :
laser feedback; laser mirrors; laser mode locking; laser noise; laser theory; optical phase conjugation; phase noise; semiconductor device noise; semiconductor lasers; 20 GHz; Lorentzian; butt-coupled phase conjugate mirrors; carrier noise level; delta function; external phase conjugate feedback; finite-low value; first-order self-phase locking; frequency noise; laser signal; laser system; noise bandwidth; phase conjugate feedback; phase noise; phase noise reduction; self-phase locking; semiconductor lasers; spectral shape; total phase variance; Frequency; Laser feedback; Laser noise; Laser theory; Noise level; Noise reduction; Noise shaping; Phase noise; Semiconductor device noise; Semiconductor lasers;
Journal_Title :
Quantum Electronics, IEEE Journal of
