Accession Number : ADA615972


Title :   DARPA SWEEPER


Descriptive Note : Final rept. Sep 2010-Dec 2014


Corporate Author : CALIFORNIA UNIV BERKELEY


Personal Author(s) : Wu, Ming C


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA615972


Report Date : Dec 2014


Pagination or Media Count : 28


Abstract : The goal of this project is to develop MEMS-based high-speed (MHz) optical phased arrays (OPAs). The OPAs have emerged as a powerful technology for agile, high- resolution, random- access pointing/tracking with multiple simultaneous beams. Applications of OPAs range from 3D display and printing, optical data- storage, telecommunication to military and other industrial applications. A wide variety of technologies have been developed for OPAs. The most mature OPAs are based on liquid crystals. They are low cost, and can be readily integrated on electronic integrated circuit drivers. The so- called liquid crystal on silicon (LCoS) technology has been used for both microdisplays as well as OPAs. However, the liquid crystal- based OPAs have some drawbacks, including slow response time, fringe field effect, and low steering efficiency at large angles. Recently, compact OPAs using silicon photonic waveguides on a silicon-on-insulator (SOI) with either wavelength tuning or thermo-optic phase modulation. Large arrays have been made using silicon integrated circuit foundries. For wavelength-tuning approach, the beam direction is dependent on wavelength, and it is not possible to achieve monochromatic beamsteering. Phase tuning using thermo-optic modulators overcome this limit, however, it suffers from high power consumption, particularly for large arrays. In addition, the maximum optical powers in silicon photonic OPAs are limited by the power handling capability of sub-micron-sized waveguides.


Descriptors :   *GRATINGS(SPECTRA) , *PHASED ARRAYS , GALLIUM ARSENIDES , INTERFEROMETRY , MICROELECTROMECHANICAL SYSTEMS , MIRRORS , PHASE SHIFT , REFLECTANCE , SILICON


Subject Categories : Electrical and Electronic Equipment
      Atomic and Molecular Physics and Spectroscopy
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE