With the advent of the uncooled detectors, the fraction of infrared (IR) imaging system cost due to lens elements has risen to the point where work was needed in the area of cost. Since these IR imaging systems often have tight packaging requirements which drive the optical elements to have complex surfaces, typical IR optical elements are costly to manufacture. The drive of our current optical material research is to lower the cost of the materials as well as the element fabrication for IR imaging systems. A low cost, moldable amorphous material, Amtir-4, has been developed and characterized. Ray Hilton Sr., Amorphous Materials Inc., Richard A. LeBlanc, Amy Graham and Others at Lockheed Martin Missiles and Fire Control Orlando (LMMFC-O) and James Johnson, General Electric Global Research Center (GE-GRC), along with others have been doing research for the past three years characterizing and designing IR imaging systems with this material. These IR imaging systems have been conventionally fabricated via diamond turning and techniques required to mold infrared optical elements have been developed with this new material, greatly reducing manufacturing costs. This paper will outline efforts thus far in incorporating this new material into prototype IR imaging systems.
Recently, the chalcogenide glasses (ChG) have attracted much attention in the field of optical
communication and integrated optics. High transparency in the infrared spectral region, low phonon
energy, high nonlinear properties, and high photosensitivity at near band-gap (Eg 2.35 eV,
a 1-2 x iO cm1 at 5 14 nm) are important characteristics of these glasses. In particular, the
photosensitive effects, among them photodarkening and giant photoexpansion (2-5%) , have been
extensively studied and several holographic elements, such as microlenses, diffraction and Bragg
gratings, and channel waveguides have been realized in fiber, bulk, and thin film forms of these
materials [2-4]. In this work, we report for the first time to our knowledge, the observation and study of
the strong polarization dependent photoinduced surface relief gratings in As2S3 thin films. A model to
describe the observed phenomena is also presented.