A Glan Laser Polarizer is a polarizing optic consisting of two identical right-angle prisms made from birefringent crystalline materials. Like most polarizers, the function of a Glan Polarizer is to screen certain polarization components of light.
The working principles of Glan Laser Polarizer or Glan Polarizer are identical: exploiting the different refractive indices between the o component and the e component stemming from the birefringent nature of crystal and the critical angle to realize the filtering of polarization components.
The prisms that compose the Glan laser polarizer are positioned on purpose so that their optic axis orientations, which are parallel to the plane of reflection and perpendicular to the proceeding beam, are the same. Take the example of a calcite Glan laser polarizer, first, when a light beam strikes at 90° to one of the terminals of the Glan laser polarizer, because of calcite’s birefringent properties, the light beam divides into two components, the ordinary component (the s polarization) and the extraordinary components (the p polarization). However, since the light beam enters along the normal of the terminal face, both the ordinary component and the extraordinary components will not deviate at the air-to-calcite interface but will encounter refraction at the conjunction where the two prisms are assembled.
Assume their angle of incidence at the interface of the two constituent prism equals the angle θ, angle θ is equivalent to the angle between the oblique face and the right-angle face of the prism. θ becoming the incident angle implies that for the o component, the incident angle is greater than the critical angle, which triggers the total internal reflection (TIR). The ordinary component will be reflected and rejected, Whilst, for the extraordinary component, the incident angle is smaller than the critical angle, permitting it to pass through and emit a beam of linear polarization. The transmitted extraordinary light does not deviate from its initial direction and is of high linear polarization purity.
Shalom EO’s Glan Laser Polarizers are constructed with an air-spaced architecture, with the adhesive-free, air-gap structure, the endurance to high power is raised to greater than but not limited to 500MW/cm2@1064nm, 20ns, 20Hz. We select the materials that pass a test of laser scattering sensitivities and persist in high precision fabrication and inspection, hence an exceptional extinction ratio of 20000:1 to 200000:1 could be obtained. The black anodized aluminum housing could either be rectangular or circular, black glass to absorb the dumped light is accessible. No, one or two escape ports could be configured to prevent detrimental power absorption or even allow the utilization of the rejected ordinary component for extra power capacities.
The Glan Laser Polarizers are available in both stocked and custom versions, for standard versions, we offer three substrate materials: Calcite, Alpha-BBO, and YVO4, with broadband coatings of transmission spectrum ranging from UV, VIS, to MWIR: Calcite:350-2300nm; Alpha-BBO:200-300nm, 300-700nm; YVO4:500-4000nm. Protective coatings are also accessible. Standardized aperture sizes are accessible in stock, including:φ6mm, φ10mm, φ12.7mm, φ15mm, φ20mm. Other sizes are available upon request. Besides, Shalom EO also offers a full portfolio of Glan polarizers, including Glan Taylor Polarizers, which are appropriate for low and medium-power lasers, and Glan Thompson Polarizers which feature large acceptance angles, if you are interested, you might click on the bold text to learn more.