Pacific Coast Optics Windows
Plane Windows
Plane windows are used as substrates for a variety of applications, such as laser windows, excimer windows, output couplers, beamsplitters, beam combiners, mirrors, dichroic filters and plate polarizers. Considerations in selecting window substrates include transmission range, absorption coefficient, incident laser power density and environmental factors such as pressure, temperature, moisture, abrasion and corrosion.
Parallel Windows
Parallel Windows are similar to Plane Windows, but with parallel surfaces. These windows are well suited for applications in which the angular deviation of the transmitted beam must be kept as small as possible. Misalignment errors are also minimized when the window is repeatedly inserted and removed.
Large Wedge Windows
Large wedge windows greatly reduce or eliminate interference effects caused by multiple reflections between the front and rear surfaces of plane windows. They are well suited for use as substrates for laser output couplers, in which the reflection from the second surface must be completely eliminated from the gain medium of very sensitive lasers.
A pair of identical wedges are used to create an adjustable beam steering device.
Brewster/Oblique Windows
Brewsters angle and oblique windows are common products in our offerings. We have produced many different angles and diameters through the years. Call us to produce any angle you need. When light moves between two media of differing refractive indexes, generally some of it is reflected at the boundary. At one particular angle of incidence, however, light with one particular polarization cannot be reflected. This angle of incidence is Brewster's angle.
Brewster/oblique windows are windows designed for use at Brewster's angle (usually uncoated). This is the angle where only incident p-polarized light has 0% transmission loss. They are an economical option for coupling linearly polarized light into sealed optical systems and for selecting the polarization of light traveling in optical cavities.
Brewster windows are primarily used in laser cavities to produce a beam with a high degree of polarization purity. When unpolarized light is incident on an uncoated substrate at Brewster’s angle, the reflected portion is completely S polarized and the transmitted portion is partially P polarized. The S component in the transmitted beam is greatly reduced when it passes through the substrate more than once. This makes the output highly P-polarized. Multi-layer thin film polarizer coatings can be applied to these substrates to greatly improve efficiency and extinction ratio on a single pass through the substrate.