Single-mode vertical-cavity surface-emitting laser array with high power and narrow far-field divergence angle

We demonstrate novel structures of an 850-nm vertical-cavity surface-emitting laser (VCSEL) array for high output power, single-lobe far-field pattern, and narrow divergence angle. By using the Zn-diffusion process with proper sizes of oxide-current-confined and Zn-diffusion 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 (9 ^\circ-10^{\circ}) and high maximum single-mode output power ( \sim6.3 mW). Due to the high uniformity of single-mode performance of each VCSEL unit, the 6 \times 6 array exhibits an excellent lasing phenomenon, which includes single-lobe far-field pattern, weak in-phase coupling, narrowing of divergence angle (from 9^\circ to 4 ^\circ), and output power as high as around 104 mW. Furthermore, by measuring the bias-dependent output optical spectra in different positions of our array, the high similarity of these spectra indicates the excellent uniformity of our fabrication process for single-mode VCSEL.