Swift Optical Shutters
Key Features- No mechanical motion
- Computer control capability
- High speed
The Swift Optical Shutter is a vibration-free alternative to mechanical shutters for use in high- speed applications. It uses a Swift Liquid Crystal Variable Retarder between crossed polarizers to provide submillisecond switching for both opening and closing. Bidirectional switching time is on the order of 125 microseconds. Switching times can be further decreased if the shutter is heated to 40° C, which reduces the viscosity and birefringence. The D3060HV controller provides this temperature control capability for devices equipped with the TSC option.
At low voltages, these shutters show some haziness in the liquid crystal layer in the blue and green wavelengths. The light loss (scatter) from this haze is about 1% at 700 nm but increases monotonically to about 10% loss at 450 nm. Scatter at above 700 nm is negligible. The shutter is supplied with integral dichroic visible polarizers to provide an average contrast ratio of better than 150:1. Shutters with larger aperture sizes and with wavelength coverage to 2.1 microns are available on a custom basis.
