An algebraic-analytic model for the characterization of the frequency domain of photodiodes

Abstract A design and principle of silicon photodiodes (PD) operation in the frequency domain are presented. To further enhance the signal-to-noise ratio, a methodology is proposed regarding how to cut down the response in the frequency domain between the time constant and stability characteristics. An algebraic-analytic model is developed to obtain the frequency behavior of the PD which are used as semiconductor devices to capture optical modulated light. The proposed model consists of connecting the anode and cathode terminals of a PD, an operational amplifier (AOP) for performing a control over the frequency domain optical device. The basic idea consists in analyzing the response of the PD at different frequencies using Bode, Nyquist and Black diagrams which have been obtained by a transfer function in the frequency domain when the optical response is attenuated. Consequently, a cutoff frequency to be determined by a test signal, and thus allowing for a certain range of frequency capture for operation and application of the PD. This paper highlights several key issues in the measurement methods on frequency domain of the Si PD. In some cases, indirect signal metering of modulated light presents unwanted signals. Consequently, the RC filter responses they are frequency filtering effect. Therefore, for the improved PD measurements, might be necessary the solution in the frequency domain for transfer function and theoretical-experimental relationship on materials testing. The results show that this system has the capacity to acquire the operating range in the frequency domain and thereby calculate the cutoff frequency through the solution of the real and imaginary part of the PD-AOP transfer function model.