Reflective Dielectric Coatings as Laser Countermeasures.

摘要

Two dielectric reflectors were evaluated. The computer model predictions of the transmission spectra for these reflectors closely reproduced the experimental optical density vs wave-length data for both planes of polarization and for various angles of incidence. The dielectric film designed for use at 1060nm vs neodymium lasers affords good protection against laser radiation up to 70MW/sq cm with luminous transmittance above 90% in the visible region. Optical densities were also measured as a function of angles of incidence of the laser beam on this film. The optical density decreased from about 4.0to about 3.5as the angle of incidence increased from normal to about 30deg. A second reflector was designed to reject both 1060nm and 530nm radiation. This filter exhibited an OD of 2.0at both 1060and 530nm. The optical density remained approximately constant for angular deviations to about 40deg from the normal at power densities up to 65MW/sq cm,however,the luminous transmittance was only about 7%. Both of these dielectric devices showed good resistance to damage by high power density Q-switched Nd and 2xNd pulses. (Author)