Title :
Novel FSK heterodyne single-filter detection system using no IF frequency lock
Author :
Chung, Y.C. ; Tkach, R.W. ; Koch, T.L.
Author_Institution :
AT&T Bell Lab., Holmdel, NJ, USA
fDate :
6/1/1989 12:00:00 AM
Abstract :
A frequency-shift keyed (FSK) modulation/single-filter detection system which does not require an intermediate-frequency (IF) locking loop is reported. This system utilizes a laser frequency-locked to an atomic line (krypton 2p/sub 8/-3d/sub 1/" transition at 1.5224 mu m) as both transmitter and local oscillator. As a result, communication can be initiated without any manual adjustment to match the wavelengths of transmitter and local oscillator lasers. No significant degradation in the receiver sensitivity was observed due to the slight frequency dither used to lock the laser frequency to an atomic transition line.<>
Keywords :
distributed Bragg reflector lasers; frequency shift keying; laser frequency stability; optical communication equipment; optical filters; optical modulation; semiconductor junction lasers; 1.5224 micron; FSK heterodyne single-filter detection system; Kr; atomic transition line; frequency dither; frequency-locked laser; integrated optics; intermediate-frequency locking loop; local oscillator; local oscillator lasers; optical communications; receiver sensitivity; transmitter; Frequency shift keying; Laser noise; Laser transitions; Laser tuning; Local oscillators; Optical buffering; Optical filters; Optical receivers; Optical transmitters; Semiconductor lasers;
Journal_Title :
Photonics Technology Letters, IEEE
