InGaAs trap detector: advancing toward a short-wave infrared standard with 1% uncertainty.

Area of Science:

• Radiometry
• Optical Metrology
• Semiconductor Device Physics

Background:

• Silicon and germanium photodiodes are common standards for visible and near-infrared (NIR) light.
• Indium gallium arsenide (InGaAs) photodiodes offer superior performance for short-wave infrared (SWIR) detection (1-1.65 µm).
• Existing SWIR standards often rely on expensive and complex cryogenic radiometry.

Purpose of the Study:

• To develop and evaluate a compact InGaAs-based trap detector for SWIR radiometry.
• To assess the detector's performance as a potential standard for SWIR measurements.
• To provide a cost-effective alternative to cryogenic radiometry for photodiode calibration.

Main Methods:

• Designed a small-footprint optical trap using two off-the-shelf InGaAs photodiodes and a high-reflectivity mirror.
• Evaluated the prototype trap detector's stability, polarization dependence, and responsivity.
• Measured system detection efficiency across SWIR wavelengths.

Main Results:

• Achieved system detection efficiency exceeding 98% for wavelengths between 1 and 1.3 µm.
• Demonstrated excellent stability and low polarization dependence.
• The trap detector exhibits potential as a primary standard with 1% uncertainty for SWIR detection.

Conclusions:

• The developed InGaAs trap detector is a stable, durable, and versatile tool for SWIR measurements.
• It offers a practical and cost-effective alternative to cryogenic radiometry, with 1% uncertainty.
• This detector can reduce reliance on complex systems for photodiode calibration in the SWIR range.