Optical Surfaces Ltd has developed a new approach, using a series of pre-aligned beam collimator sub-assemblies, for Modulation Transfer Function (MTF) testing of large diameter military optical systems.
250mm aperture beam collimator system (1.5m focal length) fully assembled on an optical table. Image Credit: Optical Surfaces Ltd.
MTF is a technique, trusted by optical designers, for objectively evaluating the image-forming capability of military optical systems. As reflective beam collimators can be used to replicate a target at infinity or interim distances without parallax, they are the device of choice for performing MTF measurements.
However, to test larger diameter military optical systems (> 250mm), or those requiring an MTF system delivering longer focal length focusing, traditionally required an extremely large, heavy and expensive reflective beam collimator system.
Dr Aris Kouris of Optical Surfaces Ltd commented “Drawing upon decades of producing high performance reflective beam collimators our R&D team has come up with a novel way of addressing this challenge. We can now supply large collimators as sub-assembly kits that include a mounted off-axis parabolic mirror and a mounted folding flat that are easily assembled directly onto a standard optical table. Supplied pre-aligned at our production testing facility, once assembled a fine alignment tool allows the customer to quickly and accurately locate the focal plane and centre of the field. As an option, if required, we can also supply a protective cover to fit over your assembled beam collimator system”.
Benefiting from a lightweight compact design – Optical Surfaces beam collimator kits uniquely combine high stability and high performance, in an elegant solution for testing larger diameter or long focal length military optical systems.
The high stability and performance of these new reflective beam collimator kits is achieved using a zero-expansion parabolic mirror, manufactured to better than lambda/10 p-v surface accuracy. The off-axis design of Optical Surfaces modular beam collimators produces no central obscuration thereby ensuring highly efficient transmission is obtained. The all-reflecting design of these beam collimators is achromatic and with aluminium / magnesium fluoride coatings can operate from the UV to the infrared without adjustment.
For further information on beam collimator kits for testing military optical systems please contact Optical Surfaces Ltd. on +44-208-668-6126 / [email protected].
Optical Surfaces Ltd has been producing high precision optical components and systems for nearly 60 years. The company’s ISO 9001-2015 approved manufacturing workshops and test facilities are deep underground in a series of tunnels excavated in solid chalk where temperature remains constant, and vibration is practically non-existent. With such stable conditions testing, particularly with long path lengths, becomes quantifiable and reliable.
