Optical fiber coupling-based CARS (Coherent Anti-Stokes Raman Scattering) beam space stability test control system and method

Abstract

The invention discloses an optical fiber coupling-based CARS (Coherent Anti-Stokes Raman Scattering) beam space stability test control device and method. the system is composed of three parts of a CARS micro excitation source (100), a beam space stability detection device (200) and a beam feedback control system (300), wherein space beams outputted by the CARS micro excitation source (100) pass through the beam space stability detection device (200) to monitor the space state in real time, the space beams are adjusted through the beam feedback control system (300), and finally, the CARS microexcitation source 100 outputs beam space stability test and control. In comparison with the prior art, the space state of a pump beam remains stable when an adjustable space light delay line changes,the problem that a space light path needs to be adjusted frequently in a CARS micro imaging system to ensure space overlapping between the pump light and the Stokes light can be avoided, the operationprocess is simplified, and the detection efficiency is improved.

Description

technical field [0001] The invention relates to the field of space optics and fiber optics, in particular to the stability detection and adjustment control of the beam space state of a CARS microscopic imaging system based on fiber coupling. Background technique [0002] Coherent Anti-Stokes Raman Scattering (CARS) technology is a non-contact microscopic imaging technology that uses the resonance energy level of molecules in substances to detect. order nonlinear process. Usually, CARS microscopic imaging technology uses pump light and Stokes light to focus on the sample to be tested at the same time. When the frequency difference between pump light and Stokes light is equal to the vibration frequency of the target chemical bond in the sample, and the three satisfy Under the condition of phase matching, the anti-Stokes signal of the sample to be tested will be excited, that is, the CARS signal. In 1965, Maker and Terhune of Ford Motor Company proposed the CARS technology fo...

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Problems solved by technology

However, due to various imperfections in the adjustment process of the spatial light path (for example, the incident beam of the adjustable spatial light delay system is not completely horizontally incident, the incident angle is not equal to 45 degrees, etc.), when the delay of the adjustable spatial light delay system When the amount of light changes, the spatial state of the output beam will also change. In the CARS microscopic imaging system, since it is necessary to use a high numerical aperture objective lens to focus the combined beam to the sample, the spot at the position of the sample to be measured is very small (usually less than 1 μm), so the change of the beam position will cause the change of the spatial overlap of the pump light pulse and the Stokes light pulse, reduce the excitation efficiency of the CARS signal, and seriously affect the quality of microscopic imaging

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