A Low-Cost Flexible-Platform (LCFP) for characterization of photodetectors

Abstract

This paper presents a Low-Cost Flexible-Platform (LCFP) for measuring and characterizing photodetectors. This LCFP can characterize simultaneously up to 16 photodetectors and is composed by two main electronic circuit boards: a Transimpedance Amplifier Board (TIAB) and a Development Board (DevB). The TIAB was designed and optimized to reduce the noise increase, in order to convert photocurrents into voltages and at the same time, allowing the gain selection between one of the three values: 1 × 105 (low-gain, LG), 1 × 106 (medium-gain, MG) and 1 × 107 (high-gain, HG). The DevB is composed by 16 analog inputs, 54 digital inputs/outputs and an internal Analog to Digital Converter (ADC). It is possible to digitally change the Upper End Voltage (UEV) of the ADC's range to voltages below +5 V. The DevB can convert into the digital domain each one of the 16 analog signals from the TIAB with a resolution of 48.9 nA, 4.9 nA and 0.5 nA for the highest value of UEV (+5 V) and when either LG, MG or HG is selected, respectively. The measured data can be acquired in real-time with LabView software, which allows the real-time monitoring of the photocurrents for individual elements in the photodetector both through a numeric and graphical display. The light intensity can be defined by 8 digital outputs allowing 256 light intensity increments/steps from 0 to a maximum defined (by the lamp's manufacturer) light intensity. This LCFP can be used in industry to make quality control, e.g., when different test conditions are applied to the optical sensors/photodetectors and the user/customer need to quickly check if the response or performance is acceptable or resulted on any significant drifts. All these features combined with the low-cost under 1400 € makes this LCFP a suitable tool to quickly evaluate the performance of optical sensors/photodetectors.