An Aspheric lens focuses or collimates 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. The IR aspheric lens is also ideal for collimating light from MWIR and LWIR lasers, including Quantum Cascade Lasers (QCL).

This molded glass asphere is premounted in a stainless steel lens cell that is engraved with the part number for easy identification. These mounted aspheres have a metric thread that makes them easy to integrate into an optical setup or OEM application. The mounted aspheres are readily adapted to our SM1 series of lens tubes by using our Aspheric Lens Adapters. Mounted aspheres can be used as a drop-in replacement for multi-element microscope objective by combining the lens with our Microscope Objective Adapter Extension Tube.

The Black Diamond-2 material has several advantages over germanium, which is traditionally used for aspheric IR optics. BD-2's coefficient of thermal expansion (CTE) and thermally stable refractive index (n) result in a smaller change in focal length as a function of temperature. While germanium suffers from transmission loss as temperature increases, BD-2 aspheric lenses can be used in environments up to 130 °C. BD-2 is a chalcogenide made up of an amorphous mixture of germanium (28%), antimony (12%), and selenium (60%).

• EFL: 1.873 mm
• NA: 0.85
• CA: 4.00 mm
• WD: 0.72 mm
• DW: 9.5 µm
• Glass: BD-2
• M: Infinite
• Thread: M9 x 0.5