High-Performance Low-Divergence Angled Laser Diodes With Two-Dimensionally Tilted Sidewalls

High-performance low-divergence angled laser diodes are proposed and fabricated at a wavelength of 910 nm. Light is reflected both inward to the waveguide and downward to the lower cladding layer by the 2-D tilted sidewalls along its zigzag path in the waveguide, and thus the mode field is extended and the transverse divergence angle is greatly reduced. Experimentally, reduced transverse divergence angles by over 20
$^{\circ}$
are demonstrated in both pulse and continuous wave modes, and stable and narrow lateral divergence angles are simultaneously achieved. This device shows a promising future for improving the transverse far-field pattern by surface structure with easy fabrication.