COMPACT DIODE-PUMPED LASER SYSTEM FOR BIOMEDICAL IMAGING

光波电子公司提议开发一种紧凑型 激光二极管泵浦软组织非电离成像系统。这个 Concept的工作原理如下。两个单频激光器，当对准和 叠加在光电二极管上，在探测器中产生外差信号 与每个波束的幅度成正比。一种置于其中的散射介质 光束的路径将光散射到光束外，因此外差 信号只由未散射的光产生。如果密集的嵌入对象 使光束衰减，外差信号减弱，物体可以 被拍成影像。此外，外差信号的频率允许 使用极其灵敏的检测系统，这允许 通过较厚的样本进行成像。 Lightwave已经在一个简单的设置中演示了这个概念，它使用两个 单频二极管泵浦的NdYAG光激光器。第一阶段的目标 程序是通过优化信号来探索这个系统的极限 探测系统，探索其他可能的激光系统或 配置和测量系统特性，如空间 分辨率、信噪比和数据采集率。在 完成第一阶段，我们预计将能够产生两个 通过组织样本进行三维成像。在第二阶段，我们预计将 开发一套完整的成像系统原型。

Lightwave Electronics Corporation proposes to develop a compact diode-pumped laser system for non-ionizing imaging of soft tissue. The concept works as follows. Two single-frequency lasers, when aligned and overlapping onto a photodiode, create a heterodyne signal in the detector proportional to each beam's amplitude. A scattering medium placed in one beam's path scatters light outside of the beam so that the heterodyne signal results only from unscattered light. If a dense embedded object attenuates the beam, the heterodyne signal decreases and the object can be imaged. Additionally, the frequency of the heterodyne signal allows the use of an extremely sensitive detection system, which allows for imaging through thicker samples. Lightwave has demonstrated this concept in a simple setup using two single frequency diode-pumped Nd:YAG lasers. The goals of the Phase I program are to explore the limits of this system by optimizing the signal detection system, exploring other possible laser systems or configurations, and measuring systems characteristics such as spatial resolution, signal-to-noise ratio, and data acquisition rates. At the completion of the Phase I we expect to be able to generate two dimensional images through tissue samples. During Phase II we expect to develop a complete prototype imaging system.