The effects of reflectivities at the end of the distributed-feedback (DFB) region and of a lambda /4-shift position are compared theoretically in terms of stability of single-longitudinal-mode operation and asymmetric power distribution. The shift of the lambda /4-shift position from the center to a certain place in the DFB region, with the end reflectivities less than several tenths of a percent, is most effective for efficient power extraction and reproducible dynamic-single-mode (DSM) operation. Devices emitting at 1. 5 mu m range were fabricated by using negative and positive photoresists and using one-step holographic exposure. They exhibited single-longitudinal-mode operations just at or near the center of the stopband, i. e. , the Bragg wavelength. Slight wavelength deviations from the center are attributed to the accidental variations of phase shift from the optimal value.
|Number of pages||10|
|Journal||IEEE Journal of Quantum Electronics|
|Publication status||Published - 1986 Jul|
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Physics and Astronomy (miscellaneous)