An improved scan laser with a VO2programmable mirror

A 10.6 μm scan laser has been constructed and operated with an off-axis cathode ray tube, high reflectance multilayer thin-film structures, and a tapered plasma discharge tube. Equations are given for the switching time of a high-reflectance spot on the VO2and for the relation of scan laser output power to cavity geometry, cavity losses, and the gain of the active CO2medium. A scan capability of2.1 times 10^{3}easily resolvable directions was demonstrated, and sequential and randomly addressed spot rates of 10⁵/s were achieved. The equations relating output power and cavity mode size were experimentally verified using a nonscanned beam.     

News Media Use and Adolescents' Attitudes about Nuclear Issues: An American-Soviet Comparison

Both Soviet and American youth show a great concern about the possible effects of nuclear war, with heavy media users in both countries more optimistic, but the relation was stronger among Soviet students.     

A 10.6 µm scan laser with programmable VO2mirror

A scan laser controlled by the variable reflectance of a VO2film on a CRT faceplate has been demonstrated at 10.6 μm. The cavity is a flat field conjugate resonator with an active medium of axially flowing CO2-N2-He gas mixture. The output beam has been scanned in a circular pattern at 20 Hz. Output modulation has been observed at a raster frame rate of 45 Hz (100 percent) and at a raster line rate of 4.44 kHz (< 100 percent).     

A BS degree in photonics

Course and implementation recommendations are presented for establishing a BS degree in photonics, a discipline combining elements of both physics and electrical engineering with an emphasis in modern optics. The assumptions providing the basic framework for the work are discussed. The options available to graduates of the suggested program are pointed out     

Crystal growth and reflectance properties of thermochromic Cu2HgI4

Crystals of Cu₂HgI₄ have been grown by using a gel medium. Diffuse reflectance measurements show color vs temperature hysteresis. Also shown is a long term reflectance relaxation at room temperature. Further, there is indication of a phase which appears when grown, but does not reappear after the material has been temperature cycled.     

An electro-aerodynamic CO2scan laser

An electro-aerodynamic CO2scan laser with a vanadium dioxide control reflector has been demonstrated. Gas flow, electrical discharge, and optical path are coaxial. A gain coefficient of 0.015 cm^-1has been achieved in a tapered discharge tube with 3.175 cm limiting aperture. Scanning speed near 10⁵directions per second can be utilized over3.7 times 10_{4}resolvable directions in space. Scanning output power up to 9 W was shown.