• Ø1" CVD Laser-Grade ZnSe Substrate
• AR Coating: 8 - 12 µm
• Diffraction-Limited Performance

An expansion of Thorlabs' IR product line, This Thorlabs' Ø1" Zinc Selenide (ZnSe) Aspheric Lens offers high transmission over the broad spectral range from 0.6 - 16 µm and is available with an -F broadband AR coating for the 8 - 12 µm range to minimize surface reflection losses. This coating greatly reduces the high surface reflectivity of the substrate, yielding an average reflectance of less than 1.15% over the entire AR coating range.

ZnSe lenses are typically used as collimators for laser applications in the 0.6-16.0 µm spectral region, such as biomedical and military applications. When used for colliimation, the plano surface should face the laser diode or other point source for best performance. With a higher index (~2.4), ZnSe aspheres can be designed with shorter focal lengths and lower dispersion than comparable aspheres made from other materials, such as CaF². Due to the low absorption coefficient of ZnSe, these lenses, particularly with the -F coating, are also well suited for use with high-power CO² lasers.

These lenses are manufactured using diamond turning machines and are tested using a surface profilometer to ensure the correct aspheric profile. As a result, these aspheric lenses offer RMS wavefront errors that are typically 20 to 50 times less than similarly sized molded aspheric lenses. In contrast to their plano-convex counterparts, these ZnSe aspheric lenses focus or collimate light without introducing spherical aberration into the transmitted wavefront. For monochromatic sources, spherical aberration is often what prevents a single spherical lens from achieving diffraction limited performance when focusing or collimating light. Thus, an aspheric lens is often the best single element solution for many applications including collimating the output of a fiber or laser diode, coupling light into a fiber, spatial filtering, or imaging light onto a detector.

• Design Wavelength: 10.6 µm
• AR Coating Range: 8 - 12 µm
• Effective Focal Length (EFL): 25 mm
• Numerical Aperture (NA): 0.42
• Diameter (D): 25.4 mm
• Clear Aperture (CA): >90% of Diameter
• Working Distance (WD): 22.51 mm
• Center Thickness: 6.0 mm
• Transmitted Wavefront Error: Diffraction Limited
• Refractive Index: 2.4027 @ 10.6 µm
• F# (f/D): 0.98
• Lens Material: ZnSe