A simple interferometric method for monitoring mode hopping in tunable external-cavity semiconductor lasers
A problem in frequency tuning of external-cavity lasers is mode hopping between neighboring external cavity modes. An interferometric method is proposed for monitoring mode hopping in external-cavity semiconductor lasers. The mode-hopping events in a 1.3-/mu/m grating-tuned external-cavity laser were analyzed using this method. The average frequency of mode hopping for a 7.5-cm external-cavity length was estimated and was expressed as f/sub c/ = 2.7 x 10/sup 6/ x exp (-1.7/(I/I/sub th/ - 1)) (hertz) for 0.07 /le/ (I/I/sub th/ - 1) /le/ 0.8 (I = injection current and I/sub th/ = threshold current). The mode-hopping monitoring signal was negatively fed back to the laser using an automatic control circuit which maintained single-mode operation while the wavelength of the grating external-cavity laser was tuned.
- Research Organization:
- AT and T Bell Labs., Holmdel, NJ (USA)
- OSTI ID:
- 5774455
- Journal Information:
- J. Lightwave Technol.; (United States), Vol. 7:1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electrical mode-hopping noise in external-cavity semiconductor lasers and mode-hopping elimination by a nonoptical control loop
Measurement of Broad Absorption Features Using a Tunable External Cavity Quantum Cascade Laser