We demonstrate the possibility of detection and monitoring of bubbles emerging near the tip of an optical fiber by means of ultrasonic method. The excitation of bubbles at their resonant frequencies is performed using short ultrasonic pulses having a wide frequency range simultaneously with their modulation by means of a long pulse of a monochromatic frequency. This method allows detection of bubbles of various sizes. Used signal processing method, which allows increased bubble detection accuracy, is proposed for research in environments of biological-like medium which show continuous variations in structure and properties when exposed to optical emission. The method has been demonstrated on model objects: in a liquid and in a biological tissue phantom using various methods of bubble generation (hydrolysis and optical emission). We studied bubble formation by the tip of a fiber of the surgical laser LSP-007/10 “IRE Polus" with a wavelength of 0.97 μm coated with a highly absorbing graphite layer.

采用Nd:YAG激光对7075-T6铝合金进行激光对接焊试验，利用超声波探伤仪对对接焊试块进行探伤并获得对接焊试块的波形图，并用经验波形分析方法对波形图进行分析，得到不同焊接工艺参数下典型的超声波回波特征，建立了激光对接焊工艺参数与回波特征的对应关系。试验结果表明：激光器电压、激光离焦量和焊接移动速度对铝合金对接焊焊缝质量有着重要的影响。分析超声波探伤回波的波形，获得了7075-T6铝合金激光对接焊的最佳工艺参数。该技术为焊缝质量检测提供了一种新方法。