标题： 光致折射二次谐波检测用于超声调制光学断层扫描 显示英文标题

标题： Photorefractive second-harmonic detection for ultrasound-modulated optical tomography

摘要： 超声波调制光学断层扫描技术能够实现对组织和其他浑浊介质的清晰三维光学成像，但光调制信号难以灵敏测量。一种常见解决方案涉及光折变晶体，能够测量相对缓慢且空间分辨率较低的信号，该信号跟踪超声波的包络。我们从直观和定量两个方面重新审视了光折变检测原理，通过这一分析，我们预测光电探测器还应在超声波频率两倍处看到快速响应，以及相应高的空间频率。快速响应和慢速响应通常具有相似的幅度，并揭示互补信息，因此在相同的测量条件、积分时间和实验复杂性下，超声波调制光学断层扫描技术可以创建显著更清晰的断层图像。 显示英文摘要

摘要： Ultrasound-modulated optical tomography enables sharp 3D optical imaging of tissues and other turbid media, but the light modulation signals are hard to sensitively measure. A common solution, involving photorefractive crystals, enables the measurement of a relatively slow and low-spatial-resolution signal tracking the envelope of the ultrasound wave. We reexamine the photorefractive detection principle both intuitively and quantitatively, and from this analysis we predict that the photodetector should additionally see a fast response at twice the ultrasound frequency, and correspondingly high spatial frequency. The fast and slow response usually have similar amplitudes and reveal complementary information, thus allowing ultrasound-modulated optical tomography to create dramatically sharper tomographic images under the same measurement conditions, integration time, and experimental complexity.