Polarizers

Thin-Film Polarizers

Thin Film Polarizers (TFPs) can split a laser beam into two parts with orthogonal polarizations. Conversely, TFPs can be used to combine two beams with orthogonal polarizations. TFPs consist of a coated plate, which is oriented at Brewster’s angle with respect to the incoming beam. The thin-film coating serves to enhance the beam’s s-polarized reflectivity, while maintaining the p-polarized component’s high transmission.

Below is a TFP schematic splitting an unpolarized input beam into
s-polarized and p-polarized components:

The standard TFP reflects the s-polarized beam at Brewster’s angle; for those applications which require a 90° separation between the s-polarized and p-polarized beams, our optional turning mirror can be added. II-VI offers both ZnSe and Ge TFPs.

II-VI can design TFP coatings for wavelengths other than 10.6 microns, and formulations for other materials to meet your requirements. Contact a II-VI sales representative to discuss.

Polarizer-Analyzer-Attenuator

Polarizer-Analyzer-Attenuator is a stacked series of ZnSe plates placed at Brewster’s angle to an incoming beam. At each plate, virtually all of the p-polarized component is transmitted, while most of the s-polarized component is reflected. The net result, after the beam has traversed several plates, is a beam which is virtually only p-polarized.

Applications

• Unpolarized beam polarization
• Laser beams polarization analysis
• Continuously variable attenuation of linearly polarized beams
• Electro-optic modulation systems

Features

• High-power handling
• Visible transmission for easy alignment
• Low-insertion loss
• High-extinction ratio (> 500:1)
• Broadband operation (2 to 14 µm)
• Optional exit port or heat sink cooling