Active resonant subwavelength grating for scannerless range imaging sensors.

Kemme, Shanalyn A. ; Nellums, Robert O. ; Boye, Robert R. ; Peters, David William

Sandia National Laboratories

关键词: Frequency Modulation;    Scannerless Range Imaging Senors (Sri);    Surface Properties;    Wavelengths;    Resonant Subwavelength Gratings (Rsg).;   

DOI  :  10.2172/899360
RP-ID  :  SAND2006-7269
RP-ID  :  AC04-94AL85000
RP-ID  :  899360

美国|英语

来源: UNT Digital Library

【 摘 要 】

In this late-start LDRD, we will present a design for a wavelength-agile, high-speed modulator that enables a long-term vision for the THz Scannerless Range Imaging (SRI) sensor. It takes the place of the currently-utilized SRI micro-channel plate which is limited to photocathode sensitive wavelengths (primarily in the visible and near-IR regimes). Two of Sandia's successful technologies--subwavelength diffractive optics and THz sources and detectors--are poised to extend the capabilities of the SRI sensor. The goal is to drastically broaden the SRI's sensing waveband--all the way to the THz regime--so the sensor can see through image-obscuring, scattering environments like smoke and dust. Surface properties, such as reflectivity, emissivity, and scattering roughness, vary greatly with the illuminating wavelength. Thus, objects that are difficult to image at the SRI sensor's present near-IR wavelengths may be imaged more easily at the considerably longer THz wavelengths (0.1 to 1mm). The proposed component is an active Resonant Subwavelength Grating (RSG). Sandia invested considerable effort on a passive RSG two years ago, which resulted in a highly-efficient (reflectivity greater than gold), wavelength-specific reflector. For this late-start LDRD proposal, we will transform the passive RSG design into an active laser-line reflector.