Thermal diffusivity imaging with the thermal lens microscope
Thermal diffusivity imaging with the thermal lens microscope
复制标题
DOI：
10.1364/ao.50.006336
复制
发表时间：
2011-12-01
期刊：
影响因子：
1.9
通讯作者：
Dovichi, Norman J.
中科院分区：
文献类型：
--
作者：
Dada, Oluwatosin O.;Feist, Peter E.;Dovichi, Norman J.
同轴热透镜显微镜被用来产生基于组织样品的吸光度和热扩散率的图像。利用声光调制器对泵浦光束进行了频率从50 kHz到5 MHz的调制。泵浦和连续波探测光束与二向色镜相结合，对准倒置显微镜，聚焦到样品上。用光电二极管探测到了发射的探测光束中心强度的变化。光电二极管的信号和来自调制器的参考信号被送到高速锁定放大器。同相和正交信号被记录下来，作为样本被转换通过聚焦光束，并用于产生基于锁定放大器信号的幅度和相位的图像。振幅与吸光度有关，相位与样品的热扩散率有关。对染色的肝脏和骨组织的薄层切片进行成像，相位图的对比度和信噪比在0.1~1 MHz的频率范围内最高，在较高的频率下下降。受泵浦光斑大小的限制，幅度像和位相像的空间分辨率均为2.5微米。(C)2011年美国光学学会
A coaxial thermal lens microscope was used to generate images based on both the absorbance and thermal diffusivity of histological samples. A pump beam was modulated at frequencies ranging from 50 kHz to 5MHz using an acousto-optic modulator. The pump and a CW probe beam were combined with a dichroic mirror, directed into an inverted microscope, and focused onto the specimen. The change in the transmitted probe beam's center intensity was detected with a photodiode. The photodiode's signal and a reference signal from the modulator were sent to a high-speed lock-in amplifier. The in-phase and quadrature signals were recorded as a sample was translated through the focused beams and used to generate images based on the amplitude and phase of the lock-in amplifier's signal. The amplitude is related to the absorbance and the phase is related to the thermal diffusivity of the sample. Thin sections of stained liver and bone tissues were imaged; the contrast and signal-to-noise ratio of the phase image was highest at frequencies from 0.1-1MHz and dropped at higher frequencies. The spatial resolution was 2.5 mu m for both amplitude and phase images, limited by the pump beam spot size. (C) 2011 Optical Society of America