Title :
On the various time constants of wavelength changes of a DFB laser under direct modulation
Author :
Shalom, Hamutal ; Zadok, Avi ; Tur, Moshe ; Legg, Peter J. ; Cornwell, W.D. ; Andonovic, Ivan
Author_Institution :
Fac. of Eng., Tel Aviv Univ., Israel
fDate :
10/1/1998 12:00:00 AM
Abstract :
The temporal behavior of the optical frequency emitted by several DFB lasers under direct square wave modulation was measured using an all-fiber implementation of a Mach-Zender interferometer with an imbalance of 30 ps. The impulse response of the optical frequency to injection current modulation was found to contain a time constant as short as 10-20 ns, together with a few longer ones. The existence of such a short time constant is consistent with a thermal analysis of a laser structure with finite thermal impedance of the active region and should be taken into consideration in various wide bandwidth applications of direct modulated semiconductor lasers
Keywords :
Mach-Zehnder interferometers; chirp modulation; distributed feedback lasers; laser beams; laser feedback; optical modulation; semiconductor lasers; thermal analysis; transient response; 10 to 20 ns; 30 ps; DFB laser; Mach-Zender interferometer; active region; all-fiber implementation; direct modulated semiconductor lasers; direct modulation; direct square wave modulation; finite thermal impedance; impulse response; injection current modulation; laser structure; optical frequency; temporal behavior; thermal analysis; time constant; time constants; wavelength changes; wide bandwidth applications; Chirp modulation; Distributed feedback devices; Frequency; Laser transitions; Optical feedback; Optical interferometry; Optical modulation; Optical refraction; Optical variables control; Semiconductor lasers;
Journal_Title :
Quantum Electronics, IEEE Journal of
