Znse Zinc Selenide Technical Data Sheet

TECHNICAL DATA SHEET

ZnSe Zinc Selenide Summary Description Refractive Index1 ZnSe is a medium refractive index material (2.4 @ 10 microns) WAVELENGTH (Microns) INDEX WAVELENGTH (Microns) INDEX with good long wavelength transmission in the infrared. 0.54 2.6754 7.40 2.4201 It is a popular material choice for transmission analysis 0.58 2.6312 7.80 2.4183 of aqueous samples as it is insoluble in water. ZnSe is a 0.62 2.5994 8.20 2.4163 relatively hard and durable material, especially compared 0.66 2.5755 8.60 2.4143 to potassium bromide (KBr) and therefore is widely used 0.70 2.5568 9.00 2.4122 as a beamsplitter and for windows in portable infrared 0.74 2.5418 9.40 2.4100 spectrometers. ZnSe is widely used as a material for 0.78 2.5295 9.80 2.4077 attenuated total reflectance (ATR) measurements, 0.82 2.5193 10.20 2.4053 offering good spectral range coverage and resistance to 0.86 2.5107 10.60 2.4028 wear. It has replaced Ge in most military applications 0.90 2.5034 11.00 2.4001 such as thermal imaging since it has no free carrier absorption at elevated temperature. ZnSe is also used in 0.94 2.4971 11.40 2.3974 very high power laser systems such as laser machining. 0.98 2.4916 11.80 2.3945 1.00 2.4892 12.20 2.3915 Advantages 1.40 2.4609 12.60 2.3883 1. Zero water solubility 1.80 2.4496 13.00 2.3850 2. Good chemical resistance 2.20 2.4437 13.40 2.3816 3. Good spectral range Down to 500 cm-1 for windows 2.60 2.4401 13.80 2.3781 -1 and 600 cm for beamsplitters 3.00 2.4376 14.20 2.3744 4. High refractive index permits design of excellent broad 3.40 2.4356 14.60 2.3705 band anti-reflective (BBAR) coatings 3.80 2.4339 15.00 2.3665 5. Refractive index is almost identical to diamond thus can be combined with diamond in some unique designs 4.20 2.4324 15.40 2.3623 6. Most popular ATR spectroscopy material 4.60 2.4309 15.80 2.3579 7. Can be fabricated by diamond turning; thus can be 5.00 2.4295 16.20 2.3534 fabricated into unique aspheric lenses 5.40 2.4281 16.60 2.3487 8. Available in very large sizes 5.80 2.4266 17.00 2.3438 Disadvantages 6.20 2.4251 17.40 2.3387 1. Attacked by strong acids and bases 6.60 2.4235 17.80 2.3333 7.00 2.4218 18.20 2.3278

Specific index listed; Generic: 2.40 @ 10 microns Mid-IR Transmission – 4 mm thick ZnSe window TECHNICAL DATA SHEET

Physical Data TYPICAL USES Melting Point: 1526 °C • IR transmission analysis Density: 5.3 g/cm3 • IR detector windows Solubility in H2O: Insoluble Hardness: 120 kg/mm2 • ATR elements Appearance: Yellow crystalline • Condensing lenses Spectral Range • Imaging lenses

-1 Short Wavelength Limit: 15,000 cm (1 mm) • High power CO2 lasers Long Wavelength Limit: 461 cm-1 (2 mm), 508 cm-1 (4 mm)

Coatings The infrared throughput of ZnSe can be significantly increased with application of specialized BBAR coatings to levels exceeding 95% transmission. It may also be coated to control depth of penetration in ATR applications.

Notes Short and Long Wavelength Limits defined for which transmissivity is greater than 50% of stated crystal thickness.

1. Handbook of Optics, 3rd ed., Vol. 4, McGraw-Hill 2009

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