The interferometric signal acquired in the photodetection method, under weak feedback conditions, often has a less magnitude, typically in the microampere range (≈10–6). Due to low magnitude, the characteristical points of the interferometric signal are highly susceptible to noise originating from optical and electronic arrangements. This meager range of current signals has been translated into an appropriate voltage level for faithful signal processing. In this paper, the authors proposed a dedicated transimpedance amplifier (TIA) to convert the photodiode current from 0.05 to 0.4 mA to a voltage level between 0.1 V and 3.2 V. The TIA has been designed using OPA320 and exhibits a gain of 8 kV/A with a −3 dB bandwidth of 250 kHz. The proposed TIA is simulated in TINA-TI and validated by fabricating a four-layer PCB prototype.