Optical resonant cavity mode and loss measurement device and method based on optical cavity ring-down method

Abstract

The invention belongs to the technical field of measurement and particularly relates to an optical resonant cavity mode and loss measurement device based on an optical cavity ring-down method. The measurement device comprises a laser, an acousto-optic switch, a first spherical reflector, a plane reflector, a second spherical reflector, a polarizer, a resonant cavity fixing platform, a spectroscope, a high-resolution CCD telescoping collimation system, an image acquisition card, a high-speed detector, a high-speed data acquisition card, a master control computer, an acousto-optic switch driver and a manual piezoelectric ceramic driver. According to the device, by monitoring the specified intrinsic mode in the optical resonant cavity and the light intensity attenuation characteristic time in the cavity, the intrinsic mode and the loss of the optical resonant cavity can be accurately measured at the same time, the measurement accuracy is high, and operation is convenient to perform. Through the device, the loss in the installing and adjusting process of an annular laser resonance cavity can also be well completed, and the device has important significance in improving the performance of laser gyroscopes and the percent of pass in production.

Description

Technical field: [0001] The invention belongs to the field of measurement technology, and in particular the invention relates to a device and method for measuring optical resonant cavity mode and loss based on an optical cavity ring-down method. Background technique: [0002] High-quality optical resonators are widely used in many important fields of national defense, such as high-precision laser gyroscopes, gravitational wave detection, and high-energy lasers. The loss of each eigenmode of a high-quality optical resonator is an important performance indicator of its quality. Measuring the working mode and loss of high-quality optical resonators is a core technology for the development of high-quality optical resonators. [0003] At present, there are many methods for measuring the loss of the optical resonator, such as: direct measurement method based on DF transflectometer, spectrum method based on measuring the free spectral range of the optical resonator and calculating ...

AI Technical Summary

Problems solved by technology

Although the system excites the cavity ring-down signal that produces multiple modes in one frequency sweep period, it does not know which modes are excited, let alone excite all the modes we want to measure

The system can only get the loss of the excited mode, and cannot measure the loss of the non-excited mode

More importantly, the system only measures the ring-down signal of the excited mode and does not capture the image of the resonant mode, and it cannot distinguish the modes with similar losses (such as TEM01 and TEM10)

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