Plane Windows and Wedged Windows

Download Plane and Wedged Windows Datasheet (PDF, 228 KB)

 Application and types

We produce a wide range of the windows made of various crystal and glass materials for spectroscopy and laser applications, typically for FTIR spectroscopy, thermography, pyrometry,  CO2 lasers, Nd:YAG lasers, etc.


A very wide range of the materials is available.

Fluorides: CaF2BaF2
Salts: NaClKClKBr
Semiconductor crystals: Si (including High Resistivity Float Zone Si for FIR and THz applications)
GeZnSeZnS, GaAs
Sapphire: Sapphire
Quartz: UV - IR Fused silica
UV Fused silica
Crystal quartz
Glass: BK7 glass and its Russian analogue K8
Plastics: TPX

Specification and tolerances

We offer high quality optics at reasonable prices. The specification of the windows depends on the application and either is defined by the customer or offered by us considering the working conditions, desired performance of the optical component itself or the assembled optical system in toto, material properties, etc.

Tab.1 Specification of the windows for IR-spectroscopy.

Specification Typical State-of-the-art
Diameter tolerance, mm +0/-0.25 +0/-0.025
Thickness tolerance, mm +/-0.25 +/-0.0025
Thickness matching, mm - +/-0.001
Surface quality, scr/dig 60/40 or 40/20 better than 20/10
Surface flatness, λ @ 633 nm 2 1/10
Parallelism (wedge tolerance) 5 arc min 5 arc sec

N.B. The best possible specification depends on material and parameters combination.


Plane parallel windows

We have long experience of supplying the windows of standard (catalogue) sizes for the commonly used instruments from Perkin Elmer, Nicolette, Bruker Optics, Pike, etc.

Tab.2 Commonly used standard windows for FTIR (IR-spectroscopy) instruments.

Discs Rectangles
Diameter x Thickness Length x Width x Thickness
6 x 1 mm 25 x 12 x 2 mm
13 x 1 mm 25 x 25 x 4 mm
13 x 2 mm 29.5 x 14.5 x 2 mm
15 x 2 mm 29.5 x 14.5 x 2 mm drilled
19 x 2 mm 29.5 x 14.5 x 4 mm
20 x 2 mm 29.5 x 14.5 x 4 mm drilled
22 x 2 mm 38.5 x 19.5 x 2 mm
22 x 4 mm 38.5 x 19.5 x 2 mm drilled
25 x 2 mm 38.5 x 19.5 x 4 mm
25 x 4 mm 38.5 x 19.5 x 4 mm drilled
25 x 5 mm 41 x 23 x 3 mm
32 x 3 mm 41 x 23 x 3 mm drilled
32 x 3 mm drilled 41 x 23 x 6 mm
38 x 3 mm 41 x 23 x 6 mm drilled
38 x 6 mm 45 x 20 x 6 mm
41 x 3 mm 45 x 20 x 6 mm drilled
49 x 6 mm 50 x 25 x 6 mm
50 x 3 mm 50 x 25 x 6 mm drilled


Drawings of the drilled windows
Drawings of the drilled windows
Drawings of the drilled windows
Drawings of the drilled windows

Fig.1 Drawings of the drilled windows.


Wedged windows

In order to avoid the influence of interference effects from the surface reflections on the transmission sometimes it is preferably to use the wedged windows.

Wedged windows

Fig.2 A method to rid the optical system of unwanted reflections with using the wedge.

 A fabrication of the wedged windows with a variety of angles to customer specification is available. 



Brewster windows


For some laser applications the windows set at Brewster angle with respect to the incident light are often used in laser cavities. The p-polarized radiation transmits the Brewster angle window without any Fresnel losses and the window does not need to be coated which increases its lifetime in laser medium ambience.

Brewster angle window can be also used as a polarizer both in reflection and in transmission. In reflection, the output light is 100% s-polarized however there are some energy losses due to transmitted part of the light. In transmitted light we have 100% energy of p-polarized part of incident light however some of the s-polarized radiation is also transmitted, therefore series of windows are needed to obtain a high degree of polarization.


Brewster angle windows


 Fig.3 Brewster angle window.

 A fabrication of Brewster angle windows made of various materials and specifications in customer design is available.



A wide range of anti-reflection (AR) and broadband anti-reflection (BBAR) coatings on the windows is available, as well as other types of coatings: partial reflecting (PR) beamsplitter coatings, wavelength separating/combining coatings, environment protection coating (diamond like or DLC).

For quotation please fill in our request form.