Traveling Wave Analysis for a High-Order Grating, Partially Slotted Laser

We analyze the spectral and spatial characteristics of a partially slotted, ridge-waveguide semiconductor laser utilized for single mode operation and suitable for integration with additional optical devices. In particular, we extract the photon distribution and linewidth behavior of a high-order (37th) grating via the finite-difference time-domain method and show good agreement with the experimental data. The reflection and transmission coefficients are initially calculated via the scattering matrix method and implemented within the traveling wave equations for a current-injected quantum well laser. In particular, the radiative loss of photons and coupling factor is estimated using the reflection coefficient with results demonstrating the state-of-the-art capabilities for this laser to meet industrial requirements for linewidths under 500 kHz and a side-mode suppression ratio over 45 dB.