Temperature measurement with photodiodes: Application to laser diode temperature monitoring

The temperature feedback of solid state laser diodes and various photovoltaic devices is critical for stable and reliable usage. We demonstrate that with a simple and passive electrical measurement process and optical calibration method the temperature of a photodiode can be determined, while keeping its original purpose. We present the idea with simulation and experiments, and provide an illumination-based parameter fitting method. The presented use case is a 5.6mm IR laser diode. We used its monitor photodiode to track the temperature inside the package with significantly better temporal resolution than the off-the-shelf external heat sink sensor provides. We reached a time resolution in the range of milliseconds and achieved precision of +/- 10mK with +/- 3K absolute, uncalibrated precision. The technique is not restricted to laser diodes, it is applicable to photovoltaic cells, photodiode arrays, organic diodes as well.

Automated summary

This study demonstrates a method for determining the temperature of a photodiode while preserving its original purpose through a simple electrical measurement process and optical calibration method. The technique allows for tracking the temperature inside the package with better temporal resolution and accuracy compared to off-the-shelf external heat sink sensors.