Schlieren imaging is a trusted method for visualising density variations in these ‘invisible’ air flows. In one of the most common types of Schlieren imaging system – a source directs light onto a spherical mirror, which collimates the light and redirects it onto a second identical mirror. The resultant image may be captured by an imaging camera or on a screen.
Drawing upon decades of experience, Optical Surfaces has produced high precision concave spherical mirrors (up to 800mm diameter) for Schlieren imaging systems in a range of materials including Pyrex, Zerodur, and ULE. Using proprietary production techniques, the company’s skilled optical craftsmen routinely produce high precision spherical mirrors with surface accuracy of better than lambda/10. Combining this ultra-high precision surface finish with durable optical coatings ensures these mirrors deliver superior image quality.
Benefiting from an ultra-stable production environment and proprietary polishing techniques, Optical Surfaces is also able to routinely produce ultra smooth optical windows up to 600mm in diameter with typical wavefront error of lambda/10 and surface finish of 40/20 to 10/5. This precision manufacturing capability in optical materials including BK-7 and fused silica, which offer good homogeneity and transmission from the UV to the Near-IR, combines to provide the perfect wind tunnel optical window to ensure superior Schlieren image quality.