Bassi Andrea, Swartling Johannes, D'Andrea Cosimo, Pifferi Antonio, Torricelli Alessandro, Cubeddu Rinaldo
National Laboratory for Ultrafast and Ultraintense Optical Science, I-20133 Milan, Italy.
Opt Lett. 2004 Oct 15;29(20):2405-7. doi: 10.1364/ol.29.002405.
We describe an instrument for the time-resolved spectroscopy of turbid media that is based on supercontinuum generation in a photonic crystal fiber. The light injected into the sample consists of subpicosecond pulses that cover 550-1000 nm at 85 MHz at an average power of as much as 40 mW. A spectrometer coupled to a multianode photomultiplier tube is used to detect the light simultaneously in 16 wavelength channels, with a resolution of 5-20 nm/channel, depending on the grating. Time-correlated single-photon counting is used to produce time-dispersion curves, which one fits to the diffusion equation to determine absorption and reduced scattering coefficients. We tested the instrument by measuring the time-resolved diffuse reflectance of epoxy phantoms and by performing in vivo measurements on volunteers. The results were similar to those obtained with previous discrete wavelength systems, whereas the full spectrum (610-810 nm) acquisition time was as short as 1 s owing to the parallel acquisition.
我们描述了一种基于光子晶体光纤中产生超连续谱的用于混浊介质时间分辨光谱学的仪器。注入样品的光由亚皮秒脉冲组成，这些脉冲在85MHz频率下覆盖550 - 1000nm波长范围，平均功率高达40mW。一台与多阳极光电倍增管耦合的光谱仪用于在16个波长通道同时检测光，根据光栅不同，每个通道的分辨率为5 - 20nm。时间相关单光子计数用于生成时间色散曲线，将其拟合到扩散方程以确定吸收系数和约化散射系数。我们通过测量环氧仿体的时间分辨漫反射以及对志愿者进行体内测量来测试该仪器。结果与之前的离散波长系统所获得的结果相似，而由于并行采集，全光谱（610 - 810nm）采集时间短至1秒。
