Multi-layer far-infrared component technology

Multi-layer thin-film optics based on alternating sub-wavelength layers of silicon and air provide high index contrast to create improved components with just a few layers. Applications include ultra-high reflectivity mirrors, band-pass and band-blocking filters, anti-reflection coatings, and compact high-resolution Fabry-Perot spectrometers with broad free-spectral-range. Such components may be integrated directly into airborne/satellite and man-portable sensing instrumentation. We demonstrate a process to produce ultrathin silicon optical elements with an integral raised spacer rim to provide the requisite air gap when these elements are combined directly into a Bragg stack. Laboratory measurements confirm theoretical design specifications. Individual elements may be stacked and bonded to form Bragg mirrors and other thin-film optics.