Comparative operating characteristics of external-cavity diode lasers (ECDL’s) with either a channel substrate planar device or a multi-quantum-well (MQW) device are presented. These include the output beam profile, which is significantly altered depending on the collimating lens used (either multielement or graded index), power versus injection-current characteristics, and the optical frequency and the rf spectra. The coherence lengths of the different laser diode–collimating-lens combinations in the ECDL are measured, and a new method for calculating the coupling coefficient and the coupled values of the internal quantum efficiency and the internal lumped loss is demonstrated for the MQW device.
|Number of pages||10|
|Publication status||Published - 1995|
- Collimating lens
- Coupling coefficient
- External-cavity diode laser