OPSR enhancement of high-temperature operating shallow-surface grating VCSELs

Area of Science:

• Optics and Photonics
• Semiconductor Lasers

Background:

• Vertical cavity surface emitting lasers (VCSELs) are crucial components in various optical systems.
• Maintaining polarization stability in VCSELs, especially at elevated temperatures, is a significant challenge for applications like atomic clocks.
• Existing VCSEL technologies often struggle with polarization control under demanding thermal conditions.

Purpose of the Study:

• To develop a polarization-stable single-mode 894 nm VCSEL suitable for atomic clock applications.
• To achieve high orthogonal polarization suppression ratio (OPSRR) at elevated temperatures.
• To propose an improved fabrication technology for mass production of grating VCSELs.

Main Methods:

• Utilized shallow-surface gratings to achieve polarization stability in the 894 nm VCSEL.
• Employed displacement Talbot lithography for an improved grating VCSEL fabrication process.
• Investigated multi-mode grating VCSELs for polarization-stable applications.

Main Results:

• Achieved a polarization-stable single-mode 894 nm VCSEL with an OPSRR of 30 dB.
• Demonstrated stable performance up to a temperature of 80°C.
• Proposed a mass-producible grating VCSEL fabrication technology.

Conclusions:

• The developed shallow-surface grating VCSEL offers excellent polarization stability for atomic clock applications.
• The proposed displacement Talbot lithography enhances fabrication efficiency for mass production.
• The technology shows promise for other applications requiring polarization stability, such as high-speed free-space optical links.