Wideband infrared beamsplitter for military testing

The defence systems integrator awarded the contract to design and build the interferometer selected Optical Surfaces as its optical supply partner for this project because of its track record in producing complex, high precision optics.

Required for testing the quality of infrared optical components the Michelson type interferometer design was optimised for multi-wavelength operation in both the mid and far infrared.

Dr Aris Kouris, Sales Director at Optical Surfaces commented: "The beamsplitter is one of the most critical components of an interferometer as it divides a beam of light into two distinct paths and then recombines the two beams after introducing a difference in the two paths.

"Operating in a uniquely stable manufacturing environment our team of experienced optical craftsmen were able to produce an ultra-high precision finish (Lambda/20 p-v) on all surfaces of the beamsplitter. However, to produce the multi-wavelength operation required a big stack of dielectric coatings on the partially reflective side of the beamsplitter which caused the surface form to be distorted.

"To overcome this challenge - we quantified the amount of costing induced distortion and then applied the opposite amount of distortion when recoated to produce the required high performance optical form".