Numerical Study of an Asymmetric Equivalent $\lambda /4$ Phase Shift Semiconductor Laser for Use in Laser Arrays

Based on reconstruction-equivalent-chirp technology, an equivalent λ/4 phase shift was introduced into the center of an asymmetric sampled Bragg grating semiconductor laser that had two sections of the same lengths but different effective refractive indices. This structure could suppress the zeroth-order channel lasing effectively and enable the laser to operate in a single longitudinal mode with high stability. Such a method can also be used to fabricate a high-quality multiwavelength laser array for enhancing the yield efficiently at reduced cost.