White Papers
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Electro-Optic Behavior
Electrical Configurations. The configuration of the Pockels cell can be such that the electrical field is applied either longitudinally along the propagation direction of the light beam or transversely to it. Because of crystal symmetry and the desire for the light beam to experience no birefringence in the absence of an electric field, most KD*P Pockels cells are longitudinal-field devices all LiNbO3 and BBO Pockels cells are transverse-field devices.
Pockels cells can be configured to appear either as a capacitive load or as a portion of a coaxial transmission cable. Most INRAD Pockels cells are configured as capacitive loads with a typical capacitance of about 10 pF; the exact specifications can be found below. However, an impedance-matched design, the PKCM02, offers the advantage of being able to transmit a high voltage pulse or pulse sequence down a piece of transmission cable and have the voltage faithfully applied to the electrodes of the Pockels cell with subnanosecond rise and fall times.
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Beryllium optics and beryllium-aluminum structures for reconnaissance applications
Michael J. Russo, Stephen LoBiondo, Bryan Coon, Michel Engelhardt, William Pinzon
BAE Systems Inc., 450 Pulaski Road, Greenlawn, New York 11740
BAE Systems has developed and fielded the F-9120, a compact, lightweight, dual-band Electro-Optical/Infrared (EO/IR) long range sensor for high altitude tactical reconnaissance applications. The sensor’s weight and size allow it to be carried internally or in a pod on a variety of military aircraft. The challenge of maintaining optical performance over severe vibration and thermal environments has been met using beryllium optics coupled to a beryllium-aluminum structure. Material choices were vital to maintaining both the optical performance of the system over the environments as well as jitter control of the two-axis, inertially-stabilized gimbal. The beryllium and beryllium-aluminum combination has demonstrated unprecedented vibration performance in both laboratory and field environments. In addition, the close coefficient of thermal expansion (CTE) match between the optics and structure has enabled the sensor to meet its stringent imaging requirements over a wide temperature range as predicted.
