Off-Axis Blog

WHAT IS SURFACE ROUGHNESS? REALLY! Surface roughness addresses the topography of a surface and quantifies the variations in its height on a micro-scale. How is roughness defined? Roughness is defined by ISO standards. Depending on the type of roughness being studied, different ISO standards apply. Profile, or 2D, roughness is defined by ISO 21920. Ra and Rq are the profile values and are the arithmetic…

INTRODUCTION Controlling quality of off-axis parabolic mirrors requires tolerances that are both traceable to performance and verifiable by measurement. Primary aspheric parameters for off-axis parabolic (OAP) mirrors, include the conic constant (k), focal length (f), off-axis angle (OAA or“θ”) and off-axis distance (OAD). We defined these in our application note, “Specifying the Geometry of an Off-Axis Parabolic Mirror[i]”. Getting the OAP configuration right may be…

INTRODUCTION The growing need for advanced reflective optics operating over a broad bandwidth has motivated the development of off-axis parabolas with higher imaging performance then ever before. Specifying imaging and wavefront performance over a broad range of spatial frequencies is essential for enabling the highest levels of performance.  As system level requirements have advanced, the way we specify OAPs must also change. Within recent years…

 INTRODUCTION Optical Telescope Assemblies (OTAs) implemented in silicon carbide (SiC) provide performance advantages for space applications but have been predominately implemented in the government sector. A new generation of lightweight and thermally-stable designs is commercially available, expanding the application of SiC to small satellites. One of the major challenges in satellite telescope design is the ability to maintain performance in the thermal environment of low-earth…

Making aspheres with Robotic Polishing Aperture Optical Sciences Inc. applies two unique technologies, Zeeko robotic grinding and polishing and QED’s magnetorheological (MRF) polishing. Both technologies address the growing demand for high performance aspheric lenses and mirrors for industry and science. We offer MRF polishing through our partner Okamoto Optics and provide Zeeko Robotic polishing on optics up to 800 mm in diameter in our advanced fabrication facility in Central Connecticut. Making optical mirrors…