Research into the Photovoltaic and Photodiode Modes of Operation of Photodiodes to Be Used in the Compact Precision Laser Inclinometer

One way to increase the sensitivity of the precision laser inclinometer (PLI) is to change over from the photovoltaic mode to the reverse-biased photodiode mode. This allows a broader linear range and an improved signal-to-noise ratio. Additionally, this approach enables the use of lower resolution ADCs (14–16 bit instead of 24 bit), which significantly reduces the cost of the device. A study of the Hamamatsu S12915-1010R/66R, Thorlabs FDS-100, and Hamamatsu S3204-08 photodiodes is conducted to determine their linear range of operation in the photovoltaic and photodiode modes. The noise level of the CPLI readout channels is measured using closed photodiodes, and two modes of operation of the photodiodes in the CPLI on the signal channels are investigated. The research results indicate the possibility of using this mode of operation of photodiodes in the CPLI.