We investigate, both experimentally and theoretically, how the sidemode-suppression ratio (SMSR) of a multisection multiple-quantum-well distributed-Bragg-reflector (MQW-DBR) laser varies with tuning current. We find that as the tuning current is adjusted the wavelength and the SMSR vary, with the peak SMSR ∞ 43 dB. The output power also varies with tuning current, and we can find when the laser is near a mode hop by examination of the light versus tuning current curve. This implies that we can adjust the tuning current so that the laser frequency is near the center of the Bragg band without measuring the SMSR. Our measurements are in good agreement with theory.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering