摘要
分析了强度调制的连续激光激发的光声信号形成过程以及调制脉宽对光声信号强度的影响,发现随着调制方波脉宽的增加,生物组织吸收的光功率增加,光声信号幅值增加。研究了调制脉宽对光声成像技术轴向分辨率的影响,发现随着调制方波脉宽宽度的增加,光声信号的脉宽增加,其轴向分辨率变差。在理论研究的基础上进行了实验验证,通过方波调制的激光二极管的出射激光激发生物组织获取声信号。在激光二极管出射光功率提高受限的条件下,通过增加作用在生物组织上的光功率密度获取高分辨率、高信噪比的光声图像。对强度调制连续激光激发的光声成像技术的研究能够为光声成像技术提供一种低成本、便携式的设备,为进一步研究提供参考。
The forming process of the photoacoustic signal excited by the intensity-modulated continuous-wave laser and the effects of modulation pulse width on photoacoustic signal are researched. It is shown that the power absorbed by the biological tissue increases with the increase of the width of the modulated rectangular pulse and the amplitude of the photoacoustic signal. The effects on the axial resolution of the photoacoustic signal excited by the modulated rectangular pulse are also researched. It is shown that the width of the photoacoustic signal increases with the increase of the width of the modulated rectangular pulse, and the axial resolution of the photoacoustic imaging becomes worse. The modulated rectangular pulse of the continuous-wave laser （laser diode） is used to induce the acoustic signal. The laser power density is raised to obtain photoacoustic imaging with higher signal-to-noise ratio （SNR） and resolution when it is hard to raise the laser power. The research on the influential factor of photoacoustic signal excited by intensity-modulated continuous-wave laser in biological tissue can be used to provide a portable and lower cost instrument.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2011年第11期130-135,共6页
Chinese Journal of Lasers
基金
上海市085工程项目
上海市教委重点课程(1K-11-309-001)
上海理工大学核心课程(1K-00-309-007)
上海理工大学博士启动费(1D-11-309-001)资助课题
关键词
激光光学
连续激光
强度调制
光声成像
脉宽
调制方波
laser optics
continuous-wave laser
intensity-modulated
pbotoacoustic imaging
pulse width
modulated rectangular pulse
