High temperature single mode 795 nm vertical cavity surface emitting lasers

• The fabricated VCSEL devices exhibit excellent single-mode characteristics. • The VCSEL devices are capable of operating at a high temperature of 95 °C. • The non-circular oxide aperture endows the VCSEL with polarization characteristics . • The polarization of the device maintains stable temperature characteristics . 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 ℃, 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/℃, 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 ℃ and exhibit excellent single-mode and polarization characteristics, which lays a foundation for polarization-stabilized VCSELs with better performance.