Title :
DFB laser spectra obtained by low-frequency current dither
Author :
Hakki, B.W. ; Bosch, F.
Author_Institution :
AT&T Bell Lab., Allentown, PA, USA
Abstract :
The temporal behavior of the spectra of distributed-feedback (DFB) lasers is studied under high-bit-rate (2 Gb/s) modulation. The optical spectra are obtained by dithering the off-state laser bias current with a low-frequency (1 kHz) low-amplitude (2 mA) current. It is found that some lasers have side modes that emit only during the first approximately 125 ps of the pulse. During this short time interval, the intensity of the side mode emission is at least 10 dB stronger than that obtained from time averaged spectra. This technique is useful in understanding the high-speed dynamics of rapidly modulated DFB spectra.<>
Keywords :
distributed feedback lasers; high-speed optical techniques; laser modes; optical modulation; semiconductor junction lasers; 1 kHz; 125 ps; 2 Gbit/s; 2 mA; DFB laser spectra; distributed feedback lasers; high-speed dynamics; low frequency low amplitude current; low-frequency current dither; modulation; off-state laser bias current; optical spectra; rapidly modulated DFB spectra; short time interval; side mode emission; side modes; temporal behavior; time averaged spectra; Bit rate; Chirp modulation; Fiber lasers; Frequency; Laser modes; Optical modulation; Optical pulses; Pulse measurements; Repeaters; Stimulated emission;
Journal_Title :
Photonics Technology Letters, IEEE
