Aspheric lenses

Precision optical manufacturer REO has introduced a new range of high performance aspheric lenses fabricated from CaF2, ZnSe and ZnS substrates. These lenses offer a combination of benefits for demanding applications that require broadband or multispectral operation from visible through to infrared wavelengths, such as military range-finding and target designation. Advantages include high surface accuracy (~λ/4 at 633nm) to achieve small focused spot sizes, low surface roughness (40-50Å rms) for minimal scatter and loss, and sophisticated, multi-layer thin film coatings. In particular, these coatings offer multispectral performance and high laser damage threshold, and are produced with a dense structure to yield exceptional environmental stability. The company states that these advantages can be maintained even at unusually thin lens profiles, meaning that the aspheres can deliver weight advantages for man-portable, field, and airborne applications.

REO’s aspheres are produced utilising single point diamond turning technology, which enables highly accurate reproduction of virtually any rotationally symmetric aspheric shape. In addition, REO can also employ diamond turning to create a surface diffractive phase profile, enabling more sophisticated functionality, such as achromatisation of single element lenses. REO also has extensive capabilities for machining lenses to yield both centred and off-centre through holes or to achieve shapes other than circular.

REO fabricates and coats these aspheric lenses in high volume on a custom basis. Small prototype batches can be ordered for evaluation and development purposes. Typical diameters for these components range from 0.25-inch to 8-inch, depending upon substrate material.