ZnSe Lens

Zinc Selenide ZnSe is a transparent, yellowish polycrystalline substance which transmits in the range range 0.5-21µm. It is ideal for mid-infrared applications, but can also transmit some visible light. This means optics incorporating ZnSe lenses lend themselves to visual inspection when IR light is turned off.

A ZnSe lens is a precision optic commonly used in thermal imaging, high power CO2 laser systems and in the life sciences. 

1. Key Properties of ZnSe Lenses

1) Zinc Selenide ZnSe is a transparent, yellowish polycrystalline substance which transmits in the range range 0.5-21µm. It is ideal for mid-infrared applications, but can also transmit some visible light. This means optics incorporating ZnSe lenses lend themselves to visual inspection when IR light is turned off.

2) Absorption coefficient of Zinc Selenide is 0.0005 cm-1 at 10.6 μm. When used at infrared wavelengths, ZnSe lenses have less than 0.3 percent total absorption, as measured using CO2 laser calorimetry. This ultra-low absorption means ZnSe lenses can reduce energy loss and increase accuracy in sensitive instrumentation: a crucial advantage for applications in laser optics where energy is focused on a very small point.

3) Zinc Selenide has a melting point of 1525°C and a thermal conductivity is 18 W m-1 K-1 at 298K. The thermal expansion coefficient is 7.1 x 10-6 /°C at 273K. Zinc Selenide lenses exhibit a high resistance to thermal shock and can be used in thermally demanding applications.

4) The reflectivity of  Zinc Selenide is typically 29.1% at 10.6 μm (2 surfaces), and our ZnSe lenses can be AR coated for minimal energy loss.  Since this is a soft material and can be easily scratched, we suggest kindly using especial care when handling your ZnSe lenses.

2. Production of a ZnSe Lens

1) The highest quality ZnSe blanks are those which have been chemically vapor deposited in production, and these are the blanks we use to craft our precision lenses.  

2) After a blank has been roughly cut to the desired size and shape, diamond turning is used to match the exact curve, roughness, and dimension specified in the design.  

3) The surface of the lens is polished to high standards.

4) For high performance in CO2 laser focusing applications, the lenses are supplied with no coating. However, anti-reflection or other optical coatings can be applied as desired.

5) Lenses are rigorously tested to ensure it fully meets your specifications as well as all applicable standards. State of the art metrology equipment is used to test for accuracy and performance.

3. Factory Standard

  Lenses are carefully tested before leaving our factory to ensure it meets all specifications. Please do not hesitate to contact us to discuss a custom order, to inquire about our manufacturing limit or custom specifications.

  1) Substrate Material: ZnSe

  2) Shape: Spherical Plano-Concave, P-Convex, Concave-Convex or Aspheric

  3) Surface Figure: λ/10 or better before coating at 10.6μm

  4) Surface Quality: 40-20 or better per MIL-PRF-13830B

  5) Dimensional Tolerance: + 0.00mm, – 0.25mm

  6) hickness Tolerance: +/- 0.25mm

  7) Chamfer: 0.35mm at 45° (typical)

  8) Concentricity: < 0.05mm

  9) Focal Length Tolerance: +/- 2%

 10)  Antireflection Coating: Ravg < 0.6% per surface at 3-5μm

                                            Ravg < 0.75% per surface at 8-12μm

                                            Ravg < 0.5% per surface at 10.6μm

 11) Clear Aperture: Exceeds central 85% of dimension

 12) Absorption: <0.3% total absorption as measured by CO2 laser calorimetry

 13) Design Wavelength: 10.6μm

4. Applications

1) ZnSe is used to form II-VI light-emitting diodes and diode lasers, which emits blue light.

2) ZnSe doped with chromium (ZnSe:Cr) has been used as an infrared laser gain medium emitting at about 2.4 μm.

3) It is used as an infrared optical material with a remarkably wide transmission wavelength range (0.45 μm to 21.5 μm). The refractive index is about 2.67 at 550 nm (green), and about 2.40 at 10.6 μm (LWIR). Similar to zinc sulfide, ZnSe is produced as microcrystalline sheets by synthesis from hydrogen selenide gas and zinc vapour.

4) ZnSe activated with tellurium (ZnSe(Te)) is a scintillator with emission peak at 640 nm, suitable for matching with photodiodes. It is used in x-ray and gamma ray detectors. ZnSe scintillators are significantly different from the ZnS ones.

5. People also ask

1) What is ZnSe used for?

     A ZnSe lens is a precision optic commonly used in thermal imaging, high power CO2 laser systems and in the life sciences.

2) What is the name of ZnSe?

     Zinc Selenide (ZnSe)

3) What is ZnSe lens?

    A ZnSe lens is a precision optic commonly used in thermal imaging, high power CO2 laser systems and in the life sciences.

4) How do you make ZnSe?

    The ZnSe product was prepared by first dissolving 2 g of PVP in 70 mL of deionized water, followed by vigorous stirring for 2 h at 70 °C. Next, 0.4 mmol of selenium powder was dissolved in 80 mL of ethylenediamine.