White Papers

X-Ray Toroids

Using toroidally shaped crystals is more practical now than ever, thanks to the high quality of synthetic crystals and state-of-the-art optical manufacturing and testing methods. For years, curved x-ray crystal optics have been used to analyze x-ray emissions in applications like analytical chemistry micro-probes and plasma diagnostics.

Production of Stilbene for Fast Neutron Detections

The organic scintillator stilbene is well-known as an excellent material for detection of fast neutrons in a gamma-ray background. Unfortunately, applications have been limited due to availability. Commercial production of stilbene using melt crystal growth techniques has not yielded material in large quantities and sizes. Solution crystal growth of stilbene has recently been demonstrated by researchers at Lawrence Livermore National Laboratory (LLNL) as a cost-effective alternative with the potential for scaling to large, high quality crystals. Inrad Optics is pursuing stilbene solution growth and fabrication in collaboration with LLNL to transfer that research to a production process.

Beryllium optics and beryllium-aluminum structures for reconnaissance applications

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.

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.

Zinc Germanium Phosphide (ZGP)

Zinc Germanium Phosphide (ZGP) is one of those few reliable, efficient, high quality non-linear crystals that is beginning to dominate applications in a particular spectral region due to the unique properties of the material. A high non-linear coefficient (75 pm/V), good thermal conductivity (35 W/mK), relatively high Laser Damage Threshold (2-5 J/cm2 typically), and transparency with phase-matchability over the 2 μm – 8 μm range (and beyond) highlight the desirable properties of the material.