The effect of temperature instability on the threshold sensitivity of photodetectors based on A$^{\mathrm{III}}$B$^{\mathrm{V}}$ photodiodes

The dependence of the sensitivity of photodetectors based on A$^{\mathrm{III}}$B$^{\mathrm{V}}$ photodiodes on accidental variations of the temperature of its elements is analyzed. It is shown that the temperature drift of the bias level in input circuits of op-amps strongly contributes to the resulting photodetector noise up to frequencies on the order of 1 MHz. To reach the limiting sensitivities of the sensors, it is necessary to stabilize the temperature of not only the photodiode chip, but also the integrated circuit of the first amplifier stage. For most of applications, the required stabilization accuracy does not exceed $\pm$ 0.1$^\circ$C. As a result of the analysis, prototype high-sensitivity medium-wavelength (2–5 $\mu$m) sensors were developed that operate without forced cooling and have a detection threshold of tens of nanowatts at a detection bandwidth of 0–1 MHz.