Photoelectric detector frequency-amplitude characteristic test method for optical fiber peg-top

Abstract

The invention discloses a method for testing the frequency characteristics of a photoelectric detector used in an optical fiber gyroscope. The signal generator generates a sinusoidal signal and adds it to the optical intensity modulator, and performs sinusoidal modulation on the optical power of the optical signal emitted by the fiber optic light source to generate an optical signal with a sinusoidal component, and the photodetector under test converts the modulated optical signal into For electrical signals, use a high-speed acquisition card to sample the electrical signals, and perform narrow-band filtering and signal processing on the acquisition results to calculate the frequency response at this frequency; the frequency sequence pre-selected by the numerical control system changes the frequency of the signal sent by the sine wave generator, and the test The frequency response of a series of frequency points can be combined to obtain the amplitude-frequency response curve of the tested photoelectric detector, and sent to the terminal computer for display and storage; all testing processes are controlled by the numerical control system, automatic measurement, fast testing speed and high precision , can be used to carefully measure the frequency performance of a photodetector over the entire operating frequency range.

Description

technical field [0001] The invention relates to a fiber optic gyro sensor technology, in particular to a method for testing the frequency characteristics of a photoelectric detector used in a fiber optic gyro. Background technique [0002] The amplitude-frequency characteristic curve refers to the numerical curve with the frequency as the abscissa and the gain of the system under the sinusoidal signal input at the frequency as the ordinate. This curve is used to evaluate the change characteristics of a system gain with frequency; The frequency is the abscissa, and the phase delay of the output signal of the system under the input of the frequency sinusoidal signal is the numerical curve of the ordinate. This curve is used to evaluate the variation characteristics of a system phase delay with frequency. The comprehensive amplitude-frequency characteristic curve and phase-frequency characteristic curve can describe the response mode of a system to any input signal, and charact...

AI Technical Summary

Problems solved by technology

[0005] Originally, a commonly used method for testing the frequency characteristics of photodetectors used in optical communications is to use a step signal test method. This method is convenient for obtaining 3dB bandwidth indicators, but it cannot obtain detailed amplitude-frequency characteristics and phase-frequency characteristic curves, and the method The method is greatly affected by noise, the resolution is poor, and it is difficult to change the amplitude-frequency characteristics of 0.1dB or even smaller, and it is not suitable for accurate measurement of the frequency characteristics of the photodetector used in the fiber optic gyroscope; another method is to use an oscilloscope and a signal source to test method, but it also has the shortcomings of being unable to accurately quantify, affected by test noise, inconvenient testing, and low efficiency. It is also impossible to accurately measure the frequency characteristics of photodetectors used in fiber optic gyroscopes

Images