Polarization-stable single-mode 795 nm grating-coupled surface-emitting laser for quantum sensing

Area of Science:

• Optoelectronics
• Laser Physics
• Quantum Technologies

Background:

• Surface-emitting lasers are crucial for various applications.
• Achieving stable, single-mode operation with high polarization purity remains a challenge.
• Existing technologies often face limitations in power consumption and thermal management.

Purpose of the Study:

• To demonstrate a novel polarization-stable, single-mode grating-coupled surface-emitting laser (GCSEL).
• To achieve high performance metrics including side-mode suppression ratio (SMSR) and orthogonal polarization suppression ratio (OPSR).
• To explore the potential of GCSELs for quantum sensing and other demanding applications.

Main Methods:

• Fabrication of a grating-coupled surface-emitting laser operating around 795 nm.
• Characterization of laser performance including threshold current, electrical resistance, and thermal resistance.
• Analysis of optical properties such as SMSR, OPSR, and far-field beam divergence.

Main Results:

• Demonstrated a polarization-stable, single-mode GCSEL with SMSR of ~40 dB and OPSR of ~25 dB.
• Achieved a low threshold current of ~4.8 mA and low electrical resistance of 53 Ω.
• Obtained low thermal resistance (~1 K/mW), comparable to record VCSELs, and good beam quality (~14.5°x14.7° divergence).

Conclusions:

• The developed GCSEL offers a new pathway for producing high-performance, polarization-stable, single-mode surface-emitting lasers.
• The simple fabrication process and excellent performance metrics (low power, low thermal resistance, good beam quality) make it suitable for quantum sensing (atomic clocks, magnetometers, gyroscopes) and broader applications.
• Wafer-level testing capabilities further enhance its practical utility.