High temperature single mode 795 nm vertical cavity surface emitting lasers

This paper presents the design and fabrication of the single-mode 795 nm vertical cavity surface-emitting laser for high-temperature operation, which serves as the laser source of a rubidium atomic clock. The design of the structure is based on the fiber waveguide theory and the gain-mode mismatch principle, resulting in a single- mode output and stable high-temperature performance. A single-mode VCSEL was fabricated and characterized. Power-current and spectral measurements were conducted, revealing that the threshold current is 0.95 mA and the maximum output power is 1.863 mW at room temperature. At 95 degrees C, the threshold current increased to 1.11 mA, while the maximum output power decreased to 0.654 mW. The output wavelength remained at 795 nm, with a temperature drift coefficient of approximately 0.061 nm/degrees C, and the single-mode suppression ratio exceeded 30 dB. Polarization characteristics were obtained through a non-circular oxide aperture. The orthogonal polarization suppression ratio exceeded 20 dB at operating current. This study demonstrates the preparation of 795 nm VCSEL devices that operate at 95 degrees C and exhibit excellent single-mode and polarization characteristics, which lays a foundation for polarization-stabilized VCSELs with better performance.