Thermal-gradient enhanced current spreading in D.H. lasers
Abstract
Observed differences in light output versus current between CW and short-pulse operation of (GaAl)As lasers have generally been considered as due to increase in active-region temperature under CW operation. However, by carefully considering the temperature rise in the active region, the present study experimentally establishes that, for exactly the same active-region temperature and total pumping current, the laser emits significantly less light in the CW mode than in the pulse mode of operation. This difference becomes larger as the input power increases. The thermoelectric (Seebeck) effect can explain this observation. The temperature gradient induced by CW operation causes current to flow away from the stripe region, leading to excess waste current and reduced light output.
- Publication:
-
Electronics Letters
- Pub Date:
- November 1978
- DOI:
- 10.1049/el:19780520
- Bibcode:
- 1978ElL....14..769L
- Keywords:
-
- Electric Current;
- Gallium Arsenide Lasers;
- Heterojunction Devices;
- Seebeck Effect;
- Temperature Gradients;
- Aluminum Gallium Arsenides;
- Continuous Wave Lasers;
- Laser Modes;
- Laser Outputs;
- Pulsed Lasers;
- Semiconductor Lasers;
- Lasers and Masers