Non-contact photoacoustic detecting method and device based on optical interferometry

Abstract

The invention discloses a non-contact photoacoustic detecting method based on optical interferometry. The method comprises the following steps of S1, photoacoustic stimulation, S2, optical coherent detection, S3, balance adjustment and S4 detecting window locking. The invention further discloses a non-contact photoacoustic detecting device based on optical interferometry and used for achieving the method. According to the method, the problem that acoustic coupling media must be used in current photoacoustic imaging is solved, and the application range of photoacoustic imaging is widened. High sensitivity is achieved, light spots of probe light can be focused to the micrometer or submicron scale, and high lateral resolution is achieved. Optical detection is adopted, high-speed scanning is easy, and therefore imaging speed can be increased. Real-time detection is carried out to interfere with system sensitivity, balance adjustment is carried out on probe light intensity, and photoacoustic detection is carried out in the state of the highest system sensitivity. The non-contact photoacoustic detecting device based on optical interferometry is further provided, and the stability and repeatability of imaging can be effectively improved.

Description

technical field [0001] The invention relates to a non-contact photoacoustic detection method and device based on an optical interference method, and specifically belongs to the technical field of photoacoustic detection. Background technique [0002] Photoacoustic imaging (PAI) is a high-resolution, high-contrast three-dimensional imaging technology developed in recent years. Its imaging principle is the photoacoustic effect. Seconds) after the sample is irradiated, the sample will cause its own temperature rise due to the absorption of light energy, and the temperature rise will cause the sample to thermally expand rapidly and generate ultrasonic waves, which is the process of photoacoustic effect. The ultrasonic waves excited by the photoacoustic effect will be transmitted to the surface of the sample, and the ultrasonic waves will be detected on the sample surface with a detector to obtain a photoacoustic signal, and the light absorption distribution of the sample will be...

AI Technical Summary

Problems solved by technology

This method is extremely inconvenient to operate and lacks practicability, resulting in the inability to perform many imaging operations due to the inability to perform acoustic coupling.

At the same time, the degree of contact between the membrane and the sample also has a greater impact on the imaging results, thus affecting the stability and repeatability of the imaging

At present, there are still photoacoustic signal detection using thin-film F-P interferometer and optical fiber as pressure sensor. Although these two methods are optical methods, they belong to sound pressure detection, similar to the method of using PZT and PVDF pressure transducers. Acoustic coupling medium is still needed between F-P interferometer and fiber optic pressure sensor

[0004] The complex acoustic coupling method greatly limits the application range of PAI and affects the stability and repeatability of imaging. This is the main problem facing PAI at present. Therefore, it is necessary to develop a non-contact optical Acoustic detection method is particularly necessary

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