Device and method for measuring relative intensity noise of laser

Abstract

The invention discloses a measuring device and method for the relative intensity noise of a laser. The method is to use the principle that the phase noise index will deteriorate correspondingly after the single-frequency electric signal passes through the microwave photon link, and calculate the link by the change amount of the phase noise. Relative intensity noise of lasers in the path. The basic structure of the present invention includes a single-frequency point signal source, a microwave photon link, an optical power meter and a phase noise detector, wherein the microwave photon link is mainly composed of a laser, an electro-optical modulator, an optical coupler, and a photoelectric detector. Compared with the traditional measurement method, the advantage of the present invention is that: the measurement process is carried out at the high-frequency end of the electrical domain, avoiding the influence of various environmental noises near the DC end, and improving the measurement accuracy; the scheme does not need to consider the output power of the laser to be measured The size overcomes the limitation of the optical power to the measurement system in the traditional measurement method.

Description

technical field [0001] The invention belongs to the field of electronic measurement, in particular to a measuring device and method for the relative intensity noise of a laser. Background technique [0002] 1. Relative intensity noise of the laser [0003] With the rapid development of optoelectronic technology, lasers, as an important optoelectronic component, have been widely used in many fields such as optical communication, information storage, medical treatment, and optical sensing. In the fields of optical storage and optical communication, the relative intensity noise of the laser is one of the important parameters that determine the performance of the system. The RIN of the laser will affect the signal-to-noise ratio and sensitivity of the communication system. [0004] The relative intensity noise of a laser originates from the spontaneous radiative transition from a high-energy band to a low-energy band in a semiconductor, which can be expressed as: [0005] ...

AI Technical Summary

Problems solved by technology

The traditional solution needs to directly inject the output optical power of the laser into the photodetector. When the output optical power is large, it will obviously exceed the saturated input optical power of the photodetector, resulting in errors in the electro-optic noise conversion, and may even exceed the photodetector. The maximum input optical power, causing damage to the photodetector

[0013] (2) Near DC noise is relatively large, which affects RIN measurement accuracy

For electronic devices, the frequency spectrum near the DC side is very rich and subject to external interference. These additional noises will be parasitic into the frequency spectrum of RIN through the photodetector and electric amplifier, reducing the measurement accuracy

[0014] Based on the above analysis, it can be seen that the measurement accuracy of the current measurement scheme for the RIN noise of the laser is not high, and the limitation is relatively large. How to accurately measure the RIN of the laser is an important bottleneck in the fields of optical communication and microwave photonics.

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