Achromatic off-axis paraboloids suitable for broadband applications

Jon Lawson

Off-axis paraboloids from Optical Surfaces are used for undertaking applications including high power laser focusing, focusing upon astronomical objects, collimating reference wave fronts, beam expansion, MTF measurement, MRTD testing and bore sight alignment for missile guidance systems.

Optical Surfaces’ Off-Axis Paraboloids are particularly suitable for broadband and multiple-wavelength applications thanks to their completely achromatic performance characteristics.

Off-axis paraboloids from Optical Surfaces are routinely selected by leading establishments around the world for undertaking applications including high power laser focusing, focusing upon astronomical objects, collimating reference wave fronts, beam expansion, MTF measurement, MRTD testing and bore sight alignment for missile guidance systems.

Drawing upon its stable production environment, and the skills of its highly experienced engineers and craftsmen, Optical Surfaces can produce off-axis paraboloids up to 600 mm in diameter.

Using proprietary polishing techniques Optical Surfaces can, depending on the surface accuracy required, achieve the natural limit to the off-axis angle of around 25-30 degrees, surface accuracies of lambda/20 p-v and surface micro-roughness of 1 nm rms.

A wide range of high performance coatings is available for standard and custom off-axis paraboloids including metallic with or without protective overcoat, multilayer dielectrics and ultra-hard coatings.

Off-axis paraboloids are one of the most common type of aspheric used in optical instruments. They are free from spherical aberrations, and thus focus a parallel beam to a point or a point source to infinity.

Off-axis paraboloids provide an unobstructed aperture allowing complete access to the focal region as well as reducing the size and minimising the weight of a design. They are especially suitable for broadband or multiple wavelength applications due to their completely achromatic performance.

All together these advantages produce a cost-effective solution for many optical design problems with no compromise in performance.

Production approved to ISO 9001-2008 the quality of off-axis paraboloids from Optical Surfaces is ensured using a range of interferometric and surface test measurements on all optics and optical systems leaving the factory.