Stable Single-Mode 795 nm Vertical-Cavity Surface-Emitting Laser for Quantum Sensing

Area of Science:

• Optics and Photonics
• Semiconductor Devices

Background:

• Vertical-cavity surface-emitting lasers (VCSELs) are vital for applications requiring single-transverse-mode output.
• Existing VCSELs face challenges in maintaining stable single-mode operation for demanding applications like quantum sensing.

Purpose of the Study:

• To achieve stable single-transverse-mode lasing in VCSELs with enhanced output characteristics.
• To develop a VCSEL suitable for ⁸⁷Rb atom quantum sensors.

Main Methods:

• Fabrication of VCSELs utilizing an extended-2λ-cavity design.
• Incorporation of an oxide aperture with a diameter of 7.08 μm.
• Characterization of lasing performance, including output power, linewidth, and side-mode suppression ratio (SMSR) across a temperature range.

Main Results:

• Stable single-transverse-mode lasing was successfully demonstrated.
• A high output power of 6.8 mW and a narrow linewidth of 49.8 MHz were recorded at room temperature.
• Consistent single-mode emission at 794.8 nm with an SMSR > 40 dB was maintained from 25 °C to 85 °C.

Conclusions:

• The extended-2λ-cavity VCSEL meets the stringent requirements for ⁸⁷Rb atom quantum sensors.
• Monolithic integration of the extended cavity offers a cost-effective path to high-performance VCSELs.
• This technology is poised to enhance the commercial viability of VCSELs in quantum sensing and related fields.