Engineering Research Equipment - Submillimeter Laser System

毫米波频率的新实验表明，使用专门开发的材料会产生重要的非线性效应。 在每种情况下，由于可用的材料和功率密度，观察都相对困难。 在较短的波长下，这些非线性效应变得明显更大并且更易于研究。 我们更新颖的实验之一涉及相位共轭，这是可见波长研究的一个重要且有用的领域，但在较长波长下尚未实现。 使用人造克尔介质，我们能够演示波导中的四波混合和相位共轭。 更高频率的使用将使这一概念关键地扩展到自由空间。 另一组实验使用高温超导薄膜来制造独特的可调谐准光学滤波器。 我们正在研究的特性，涉及成对超导电子的浓度，当在亚毫米频率下观察时，这些特性将对所施加的激光场更加敏感。 因此，这项 NSF 工程研究设备拨款将用于购买光泵分子气体激光系统，该系统将产生连续波亚毫米和远红外辐射。 除了在非线性效应和超导结构方面开辟一系列新实验之外，这项工作还将在遥感和通信领域具有重要的应用。

New experiments at millimeter wave frequencies have shown important nonlinear effects using specially developed materials. In each case the observations have been relatively difficult with the available materials and power densities. At shorter wavelengths these nonlinear effects become significantly larger and more amenable to study. One of our more novel experiments involves phase conjugation, an important and useful area of research at visible wavelengths, which had not been achieved at longer wavelengths. Using an artificial Kerr medium we were able to demonstrate four wave mixing and phase conjugation in waveguides. The use of higher frequencies will permit the crucial extension of this concept to free space. Another set of experiments uses high temperature superconductor films to make unique, tunable quasi-optical filters. The properties we are studying, involving concentrations of paired superconducting electrons, will be much more sensitive to applied laser fields when observed at the submillimeter frequencies. This NSF Engineering Research Equipment Grant will therefore be used to purchase an optically pumped molecular gas laser system which will generate CW Submillimeter and Far Infrared radiation. In addition to opening up an entire range of new experiments in nonlinear effects and superconducting structures, this work will have important applications in remote sensing and communications.