Single-Mode Vertical-Cavity Surface-Emitting Lasers Array With Zn-Diffusion Aperture for High-Power, Single-Spot, and Narrow Divergence Angle Performance

A single-mode vertical-cavity surface-emitting laser (VCSEL) array at 850 nm with excellent performance in terms of high output power, single-lobe far-field, and narrow divergence angle has been demonstrated. By use of the Zn-diffusion process with proper sizes of oxide current-confined and Zn-diffusion optical apertures, each unit of VCSEL in the demonstrated array is highly single-mode (side-mode suppression ratio 30 dB) with a narrow far-field divergence angle (~5°) and an extremely high maximum single-mode output power (~7.1 mW). Due to the excellent single-mode performance of each VCSEL unit, the 10 × 10 array exhibits a single-lobe and nearly circular symmetric far-field pattern, very narrow divergence angle (~4°), and output power as high as around 187.4 mW. Furthermore, its bias-dependent output optical spectra measured in different positions of array shows very high similarity. This result indicates that the excellent uniformity of single-mode performance of each VCSEL unit in the array. The far-field pattern simulation results indicate that although the coherence in our array is low, its output beam quality is as high as that of a single-mode unit VCSEL, which exhibits a near diffraction limited M square factor (M² ≈ 2).