STTR Phase II: Electro-optic Field Sensors for Far-InfraredImaging Applications

*** 小行星9805105 我们建议研究和开发一种成像和光谱系统，该系统基于超宽带电场传感器，该传感器覆盖了当前光谱技术通常无法实现的电磁频谱的一部分。拟议的设备将基于一种新的光电设计，该设计能够在从近DC到几个THz的频率范围内进行时域远红外光谱分析。电场传感器系统采用电光晶体中的Pockel效应。脉冲微波信号在传感器晶体中引起瞬态极化。然后，通过同步脉冲激光束探测该偏振，该同步脉冲激光束将空间和时间电场分布投影到CCD相机上。我们之前对这些成像传感器的研究已经证明了亚波长空间分辨率，飞秒时间分辨率，近DC-THz带宽，亚mV/cm场灵敏度，高达100 Hz的扫描速率，以及优于1，000，000：1的信噪比。电光检测具有平坦（非共振）光谱响应度（从近DC到几个THz）、大检测器面积（1 cm 2）和扩展的动态范围（1，000，000）。简单的检测几何结构，光学并行处理的能力，和优良的信噪比，使该系统适合于实时，2-D相干远红外成像应用。 潜在的商业应用包括工业检测和过程控制、FIR光谱、电场传感器和医学成像。 ***

*** 9805105 Stewart We propose to investigate and develop an imaging and spectroscopic.system based on ultra-wideband electric-field sensors that cover a portion of the electromagnetic spectrum that is generally inacessible by current spectroscopic techniques. The proposed device will be based on a new optoelectronic design which is capable of time-domain far-infrared spectroscopy across a frequency range extending from near DC to several THz. The electric-field sensor system employs the Pockel's effect in electro-optic crystals. A pulsed microwave signal induces a transient polarization in the sensor crystal. This polarization is then probed by a synchronously pulsed laser beam, which projects the spatial and temporal electric-field distribution is projected onto a CCD camera. Our previous studies of these imaging sensors has demonstrated a sub-wavelength spatial resolution, femtosecond temporal resolution, near DC-THz bandwidth, sub-mV/cm field sensitivity, up to 100 Hz scan rate, and a signal-to-noise ratio better than 1,000,000:1. The electro-optic detection has a flat (nonresonant) spectral responsivity (from near DC to several THz), a large detector area ( 1 cm2), and an extended dynamic range ( 1,000,000). The simplicity of the detection geometry, capability for optical parallel processing, and excellent signal-to-noise ratio make this system suitable for real-time, 2-D coherent far infrared imaging applications. Potential commercial applications include industrial inspection and process control, FIR spectroscopy, electric field sensor, and medical imaging. ***