Axial mode selectivity in active distributed-reflector for dynamic-single-mode lasers

The theory for design of active distributed-reflector lasers is discussed from the point of view of dynamic-single-mode (DSM) characteristics. Optimum conditions and fabrication tolerances of coupling coefficient, cavity length, length and location of phase-shifted region, and the effect of the reflection at the end mirrors are discussed. Asymmetric active distributed-reflector laser with different coupling coefficients and lengths of two corrugation regions is also proposed to improve the efficiency of the front facet output.