Del Mar Photonics - Newsletter

Window for an infrared temperature detector - request a quote

Featured Inquiry:

I am requesting a quote for a Zinc Selenide window following the drawing attached. I am looking for two or three for testing purposes. Another material that may work is Germanium, I would like a quote for this as well if possible.We are using this window for an infrared temperature detector in an injection molding process. We are looking for a steady %Transmittance between 5 and 10 micrometers. I am not sure if we need the AR coating. Does the AR coating disrupt transmittance as you get closer to 5 micrometers? Also, how would it affect the price of the window?

Del Mar Photonics quote

Zinc Selenide (ZnSe) Components

Zinc Selenide (ZnSe) is the most popular material for infrared application. Due to very wide transmission range covering 0.6 to 20 m m CVD grown ZnSe high optical quality material is used to manufacture optical components (windows, mirrors, lenses etc.) for high power IR lasers.

Physical Properties

Crystal type cubic
Lattice constant       a=5.657Å
Density 5.27 g/cm3 at 25 C
Melting point 1525  C
Refractive index 2.417 - 2.385 @ 8 - 13 m m
2.40272 at 10.6 m m
Transmission band 0.6 to 20 m m
Bulk absorption coefficient 5 ´ 10-4 cm-1 @ 10.6 m m
Young's Modulus 6.72 ´ 109 dynes/mm2
Specific Heat at 25  C 0.085 ca/g C
Linear thermal expansion 7.57 ´ 10-6 / C at 20 C

General Specifications of Zinc Selenide Optical Components

Material ZnSe
Surface Quality 40-20 scratch & dig
Clear aperture 90% of diameter
Diameter tolerance +0.0, -0.1 mm
Thickness tolerance +0.1, -0.25 mm
Surface Irregularity l /2 per inch @ 633 nm over clear aperture
Coatings Typical available coatings for ZnSe include BBAR for 0.8 to 2.5m, 3 to 5m, 1 to 5m, 8 to 12m, and the 3 to 12m spectral regions and single wavelength AR coating  at 10.6m R£ 0.5% per surface. Many other specialized wavelength bands are possible within the 0.6 to 16m range.


Vacuum viewport

Del Mar Photonics offer a range of competitively priced UHV viewports , Conflat, ISO or KF including a variety of coatings to enhance performance. Del Mar Photonics viewports are manufactured using advanced techniques for control of special and critical processes, including 100 percent helium leak testing and x-ray measurements for metallization control. Windows Materials include: Fused silica, Quartz , Sapphire , MgF2, BaF2, CaF2, ZnSe, ZnS, Ge, Si, Pyrex. Standard Viewing diameters from .55" to 1.94 ".
Coating - a range of custom coatings can applied - which include
- Single QWOT
- Broad Band AR
- V coatings
- DLC (Diamond like coating)
more details - request a quote - High-Vacuum System for High Power Lasers - AR Coated Zinc Selenide Vacuum Viewport


Zinc Selenide optical components
ZnSe window diam 12.7 mm, thickness 1 mm - diam 20 mm x 3 mm thick - diam 25.4 mm x 3 mm thick
ZnSe Zinc Selenide meniscus lenses
ZnSe Zinc Selenide Plane-Convex lenses
ZnSe Zinc Selenide High Power Plane-Convex lenses
related product: Gold Plated Silicon Mirrors
IR windows for a thermal imager on a vacuum system - FTIR|
IR Beamsplitters: ZnSe 70/30 beamsplitter for CO2 laser - 50/50 at 45 degrees
ZnSe window mounted in a 4.5 conflat for an IR photography application
ZnSe prisms  - pair of prisms for pulse compression - ZnSe cross-disperser prisms -
ZnSe rhomb
cleaning - vacuum viewport - AR coated
Broadband AR coating (BBAR 350-700nm, 450-800nm, 650-1050nm, 1050-1620nm) for Vacuum Viewport
IR UHV view ports with Broad Band Anti-reflection (BBAR) coating for IR wavelength range
ZnSe viewport CF35 UHV 2.0 to 5.0 micron wavelength range

Elliptical optics from ZnSe

Zinc Selenide custom made windows, lenses, Brewster windows, mirrors, beamsplitters and other components are available on request.

Zinc selenide most obvious and important advantage over other materials is its low absorption in the red end of the visible spectrum. This allows the ubiquitous helium neon laser to be used as a convenient and inexpensive alignment or sighting tool for infrared laser beams. Prealignment of optics may be necessary merely because the infrared beam is invisible to the eye, or in addition because the infrared laser beam is of such a high energy misdirected laser beam can be extremely dangerous to equipment or personnel.

Although zinc selenide has this clear advantage over silicon and germanium, unfortunately it is not an easy material from which to produce optics. Firstly, it is not a naturally occurring material and has to be synthesized using a difficult process (CVD). Secondly, the dust, which is generated when zinc selenide is ground and polished constitutes a significant health hazard as a cumulative toxin. Also, it is not a particularly hard substance and scratches easily.

Refractive Index

Wavelength, m















Refractive Index

















Although the internal transmittance of zinc selenide is very high (absorption <= 0.0005cm-1 at 10.6mm), the relatively high refractive index (2.4 at 10.6mm) cause reflection losses of nearly 30%. Unless such losses can be tolerated, zinc selenide optics should always be antireflection coated. Because of the high refractive index, single and double layer antireflection coatings can be very effective.

Zinc selenide is not hygroscopic unlike certain salts which are used for windows in the infrared.


Zinc Selenide - ZnSe
Zinc Selenide - ZnSe
 Model   Product Name+   Buy Now 
 PH-ZnSe-40-30-20   ZnSe hemicylindrical prism, 20 mm  Buy Now 
 PH-ZnSe-25.4-12.7   ZnSe hemicylindrical prism, 25.4 mm  Buy Now 
 R-ZnSe-25.4-25.4   ZnSe rhomb, 25.4x25.4 mm  Buy Now 
 RAP-ZnSe-12.7-25.4   ZnSe right angle prism, 12.7 x 25.4 mm  Buy Now 
 RAP-ZnSe-40-30-20   ZnSe right angle prism, 40x30x20 mm  Buy Now 
 S-ZnSe-10-10-0.5   ZnSe slide, 10x10x0.5 mm  Buy Now 
 WS-ZnSe-100-100-10   ZnSe square window, 100x100x10, coated  Buy Now 
 TR-ZnSe-52-30-20   ZnSe trapezoid, 52x30x20 mm  Buy Now 
 VP-ZnSe-45-3-2 3/4   ZnSe viewport, 2-3/4  Buy Now 
 VP-ZnSe-73-4-4 1/2   ZnSe viewport, 4 1/2  Buy Now 
 VP-ZnSe-32-3.5-2 3/4   ZnSe viewport, dia. 32 mm, thickness 3.5 mm, flange 2-3/4  Buy Now 
 W-ZnSe-1.5"-2.5"-1/4   ZnSe window, 38.1x63x6.35 mm, coated  Buy Now 
 W-ZnSe-105-6-AR   ZnSe window, ø 105 mm, thickness 6 mm, coated  Buy Now 
 W-ZnSe-12.7-1   ZnSe window, ø 12.7 mm, thickness 1 mm  Buy Now 
 W-ZnSe-20-3   ZnSe window, ø 20, thickness 3 mm  Buy Now 
 W-ZnSe-25-2-AR   ZnSe window, ø 25, thickness 2 mm, coated  Buy Now 
 W-ZnSe-25.4-2-AR-3-1   ZnSe window, ø 25.4 mm, thickness 2 mm, AR coated 3-12 m  Buy Now 
 W-ZnSe-25.4-3   ZnSe window, ø 25.4 mm, thickness 3 mm  Buy Now 
 W-ZnSe-60-3-K   ZnSe window, ø 60 mm, thickness 3 mm, coated  Buy Now 
 W-ZnSe-76.2-3-K   ZnSe window, ø 76.2 mm, thickness 3 mm, coated  Buy Now 


Sapphire components
Sapphire Circular Windows - Square & Rectangle - Rods
Sapphire & Ruby Rings - Sapphire & Ruby Balls - Sapphire & Ruby Nozzles
Sapphire Lenses - Ball & Seat - Special Products - Sapphire Vee & Cup Jewels
Sapphire Ceramics - Ceramic Sleeves - Ceramic Holes - Ceramic Rods
Sapphire & Ruby Orifices - Sapphire & Ruby Tubes - Sapphire Components
Sapphire Half Round Rod - Sapphire Windows - Rods & Tubes - Special Part
Sapphire Prism - 5x5x5 - Sapphire Chisel - Sapphire Square Rod

Sapphire rods for HPLC: Agilent Technologies - Beckman Coulter, Inc. - Cecil Instruments - Dionex Corp  - Hitachi, Ltd. - PerkinElmer, Inc. - Shimadzu Scientific Instruments - Thermo Fisher Scientific - Varian, Inc. - Waters Corporation


We are looking forward to hear from you and help you with your optical and crystal components requirements. Need time to think about it? Drop us a line and we'll send you beautiful Del Mar Photonics mug (or two) so you can have a tea party with your colleagues and discuss your potential needs.


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Del Mar Photonics, Inc.
4119 Twilight Ridge
San Diego, CA 92130
tel: (858) 876-3133
fax: (858) 630-2376
Skype: delmarphotonics