Monolithically integrated multi-wavelength grating-coupled surface-emitting laser arrays with an oxide-confined structure

We propose what we believe to be a novel method for realizing monolithically integrated multi-wavelength surface-emitting laser arrays (MWSELAs) and experimentally demonstrate its feasibility. The MWSELA consists of six oxide-confined grating-coupled surface-emitting lasers (GCSELs), where the emission wavelength of each device is tuned by adjusting the period of the surface grating while maintaining an identical epitaxial structure. The fabricated six-wavelength GCSEL array achieves precise wavelength control with an average wavelength spacing of 1.6 nm. All elements in the array exhibit excellent single-mode operation, with side-mode suppression ratios exceeding 30 dB at an injection current of 12 mA and low threshold currents of approximately 1.5 mA. The proposed method offers a new pathway to realize monolithically integrated MWSELAs with flexible physical layouts through a simplified fabrication process. Its advantages-including low power consumption, stable single-mode performance, and compatibility with wafer-level manufacturing and testing-make it an ideal candidate for developing cost-effective MWSELAs.