A Method for Measuring the Power Spectral Density of Relative Intensity Noise of Light Source

Abstract

The invention discloses a method of measuring light source relative intensity noise power spectrum density. An analog-to-digital converter is used for sampling a detector signal to acquire output signal standard deviation. Output voltage of a photoelectric detector is acquired, and the optical input power of the photoelectric detector is calculated. An adjustable power attenuator is adjusted, and an optical signal output by a to-be-measured light source is attenuated to be different optical power, and thereafter a series of data is acquired for quadratic polynomial fitting, and then the light source relative intensity noise power spectrum density is calculated by using a fitting coefficient. Influences of other white noise sources on measurement results are effectively prevented, and the light source relative intensity noise power spectrum density can be measured accurately, and therefore a measuring tool is provided for light source design and interferometer design.

Description

technical field [0001] The invention relates to the optical fiber sensing technology in the optoelectronic technology, in particular to a method for measuring the relative intensity noise power spectral density of a light source. Background technique [0002] Early fiber optic interferometric precision measurement systems, such as the light source used by fiber optic gyroscopes, are narrow-band laser light sources. Due to the good spatial coherence of lasers, parasitic interference occurs at the output end due to Rayleigh scattering and end-face reflection in the optical fiber, and the parasitic interference signals are superimposed on the carried On the interference signal of useful information, the detection signal-to-noise ratio is reduced, which limits the measurement resolution of the fiber optic interferometer. [0003] The emergence of wide-spectrum light sources perfectly solves the parasitic interference problem caused by narrow-band lasers. Since the spectral widt...

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Problems solved by technology

[0008] Aiming at the shortcomings of the traditional use of electronic spectrum analyzers to measure the relative intensity noise of the light source, the present invention proposes a method for measuring the power spectral density of the relative intensity noise of the light source, using an optical power attenuator and an analog-to-digital converter to measure the relative intensity noise of the light source, It can accurately measure the relative intensity noise of the light source, and the measurement result will not be interfered by other white noise sources

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