Optical Shutters

XT Series

Maximum extinction ratio performance over a broad thermal range

Available in both circular and rectangular form factors, the XT Series Optical Shutters offer significant performance advantages in applications demanding the maximum extinction ratio over a broad thermal range.

XT Series Optical Shutters deliver optimum extinction ratio performance, often greater than 400:1 across the visible wavelength range. Even higher extinction performance is achieved over narrower bandwidths or for single laser line applications. Up to 100% duty cycle operation is possible. Our most popular Optical Shutter line, the XT Series has a broad operating temperature range, designed to meet the thermal demands of most instrumentation applications.

An Optical Shutter is a two-state device used to rapidly open and close a light path (from lens to film, for example). Optical Shutters are typically used to control the amount of time that a light-sensitive material is exposed to optical radiation

Boulder Nonlinear Systems (BNS) manufactures and sells liquid crystal based Optical Shutters for applications requiring active timing control of beam transmittance. Key features of our Optical Shutters include high-speed binary operation, high purity linear polarized output, and maximum extinction ratio performance. Since these devices are solid state - undesirable mechanical motion, associated noise, and vibration problems are eliminated..

Device Construction

XT Series Optical Shutters begin with polished, optically flat windows. After deposition of a transparent conductive coating layer (indium-tin oxide or ITO, typically) these window substrates are then evenly covered with a polymer layer, which is then rubbed or buffed, forming tiny microgrooves in the polymer layer. These microgrooves provide the alignment directionality critical in liquid crystal device production.

The coated and buffed windows are then spaced a few microns apart. The cavity between substrates is now filled with liquid crystal material and sealed.

High extinction linear polarizers are crossed, and then laminated between glass substrates. External glass surfaces are usually coated with a broadband antireflection coating, to maximize transmittance. With this crossed polarizer orientation, XT Series Optical Shutters exhibit full optical transmittance at the zero voltage state. Minimum transmission occurs at the full drive voltage level, as specified with your device.