PTC's variable retarders provide continuous adjustment and control over the polarization state in a beam path. A variable wave plate actively control the polarization state or phase delay of light .For liquid crystal variable retarders and pockels cells, the retardance is tuned over a specified range by changing the drive voltage.  

Features

Retardance Range: 20 nm to >λ

Clear Aperture:  Ø20 mm

Low Retardance Uniformity

Compatible with Voltage Controllers (Sold Separately )

Quick switching time without the absence of moving parts

Performance

Liquid crystal Light Valve provide sexcellent uniformity, low optical losses, and low wavefront distortion. Our retarders also provide a quick switching time, a broad operating temperature range, and a wide wavelength range.

Operation

A Liquid Crystal Light Valve consists of a transparent cell filled with a solution of Liquid Crystal (LC) molecules and functions as a variable wave plate. The orientation of the LC molecules is determined by the alignment layer in the absence of an applied voltage. The alignment layer is composed of an organic polyimide (PI) coating whose molecules are aligned in the rubbing direction during manufacturing. Due to the birefringence of the LC material, this LC retarder acts as an optically anisotropic wave plate. Two parallel inner faces of the cell wall are coated with a transparent conductive film so that a voltage can be applied across the cell. When an AC voltage is applied, the LC molecules will reorient from their default alignment according to the applied Vrms. Hence, a varying applied voltage can actively control the retardance of the liquid crystal light valve.