激光參數(shù)和光聲材料對超聲信號的影響

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中圖分類號：O439文獻(xiàn)標(biāo)志碼：A

Abstract： Photoinduced ultrasound is widely used in medical diagnosis， material characterization， nondestructive testing， structural health monitoring and other fields. These applications have specific requirements on ultrasonic intensity and bandwidth. This paper quantitatively analyzed the effects of photoacoustic materials and laser parameters on ultrasonic frequency and intensity. The following conclusions are drawn by relevant experiments. With the increase of the incident laser energy，the amplitude corresponding to all frequencies in the ultrasonic spectrum increases，and the incident laser energy is proportional to the amplitude of the ultrasound. Meanwhihle， the ultrasonic intensity increases by 15% with increase of 50mJ laser energy. The change of incident laser frequency has no effect on ultrasonic signal. The increase of gold nanoparticle concentration can not only enhance the amplitude of ultrasound，but also increase the frequency of ultrasound. The thin layer of gold nanoparticles and polydimethylsiloxane leads to insufficient absorption of light energy，and the thick layer causes the attenuation of the high frequency component of ultrasound. The mixture of carbon black and polydimethylsiloxane produces higher intensity ultrasound than the mixture of gold nanoparticles and polydimethylsiloxane under the same circumstances， but the frequency distribution is concentrated in the low frequency domain.

Keywords：photoinduced ultrasound;photoacousticmaterials； laserparameters; gold nanoparticles;carbonblack

引言

主動超聲檢測技術(shù)是醫(yī)學(xué)診斷、材料表征、無損檢測和結(jié)構(gòu)健康監(jiān)測的有力工具[1-12]。（剩余14758字）