Laser Micromachining of Silicon: A New Technology for Fabricating Tera Hertz Imaging Arrays

在设计低噪声、高效率的外差接收机和亚毫米波本振源时，遇到的主要障碍之一是波导结构的质量和成本。在波长短于400微米的情况下，矩形波导结构、馈角和后短路变得极其难以使用标准加工技术制造。我们使用了一种新的激光铣削技术来制造高质量的太赫兹波导元件和馈角。一旦金属化，这种结构就具有标准波导元件的特性。与使用硅湿蚀刻技术制造的波导组件不同，激光蚀刻组件几乎可以具有任何横截面，从矩形到圆形。在计算机控制下，亚毫米波混频器或乘法器的整个波导结构（包括波纹馈电喇叭！）可以在几个小时内制造到微米级的公差。激光蚀刻允许直接缩放成功的波导乘法器和混频器设计到太赫兹频率。由于整个过程是计算机控制的，制造亚毫米波波导元件的成本大大降低。利用这种新的激光蚀刻工艺，在太赫兹频率下构建高性能波导阵列接收器变得容易。我们申请资金在亚利桑那大学建立一个激光微加工系统。该系统将用于继续研究该工艺在亚毫米波成像系统制造中的应用

9800260WalkerOne of the main obstacles encountered in designing low noise, high efficiency, heterodyne receivers and local oscillator sources at submillimeter wavelengths is the quality and cost of waveguide structures. At wavelengths shorter than 400 micrometers, rectangular waveguide structures, feedhorns, and backshorts become extremely difficult to fabricate using standard machining techniques. We have used a new laser milling technique to fabricate high quality, THz waveguide components and feedhorns. Once metallized, the structures have the properties of standard waveguide components. Unlike waveguide components made using silicon wet-etching techniques, laser-etched components can have almost any cross section, from rectangular to circular. Under computer control, the entire waveguide structure (including the corrugated feedhorn!) of a submillimeter-wave mixer or multiplier can be fabricated to micrometer tolerances in a few hours. Laser etching permits the direct scaling of successful waveguide multiplier and mixer designs to THz frequencies. Since the entire process is computer controlled, the cost of fabricating submillimeter waveguide components is significantly reduced. With this new laser etching process, the construction of high performance waveguide array receivers at THz frequencies becomes tractable. We request funds to construct a laser micromachining system at the University of Arizona. The system will be used to continue our research into the application of this process to the fabrication of submillimeter-wave imaging systems.***