Tag Archives: measuring optical elements

Video Shows How to Measure an Optical Wedge Substrate

Apre Instruments presents an easy, step-by-step method to measure an optical wedge substrate. This process uses an Apre laser Fizeau Interferometer along with their REVEAL interferometer acquisition / analysis software. Watch this short video to see how easy this process can be! The video demonstrates how to: Align part and reference flat Calibrate pixel size Take … Continue reading

November 7, 2022 Apre Instruments, Blog, Interferometers, Systems

Measurements with a Laser Interferometer Made Easy!

To measure prisms and substrates with a laser interferometer, you are typically forced to paint or tape surfaces. Time is wasted, parts damaged, and accuracy degraded. Spectrally Controlled Interferometry (SCI) directly measures these parts down to 150 µm OPL ((or even 75 µm on special request). No taping, no painting…just measure. SCI is simply faster and more … Continue reading

April 28, 2021 Apre Instruments, Blog, Interferometers, Systems

Measuring Radius of Curvature of Optical Surfaces

An essay from Apre Instruments describes the multiple methods used today to measure an optical surface radius: Test plates Mechanical probe Interferometer “Cateye to Confocal” The essay then discusses the benefits of Apre’s Spectrally Controlled Interferometry (SCI) measurement method, including: Easy alignment in laser mode Electronically switch to white light mode to isolate fringes to … Continue reading

November 4, 2020 Apre Instruments, Blog, Interferometers, Systems

Measuring Material Homogeneity with SCI

Optical index homogeneity is an important material parameter influencing lens performance. Laser interferometers have painstakingly measured this parameter which requires four separate measurements.  Laser interferometers have either required the use of contact plates with oft times poisonous index matching fluids or polishing a wedge into the test part to isolate the front from the back … Continue reading

October 28, 2020 Apre Instruments, Blog, Interferometers, Systems

SCI Measures Optical Domes Faster and More Accurately

Dome optics are the last component in a growing number of imaging and guidance applications. Domes protect the imaging optics from the surrounding environment without degrading optical performance. Therefore the dome’s transmitted wavefront quality is important to control since it directly influences the final image quality. Dome applications include: Underwater cameras Submersibles for robotic and manned … Continue reading

October 24, 2019 Apre Instruments, Blog, Interferometers, Systems

Measuring Prisms: Multiple Wavefront Channels in One Setup

Prism assemblies are difficult optical elements to measure. Back reflections from multiple surfaces and multiple channels make laser interferometry incapable of making these measurements. Spectrally Controlled Interferometry (SCI), available from Apre Instruments, offers an easy-to-use, accurate method to measure these components for the first time. A laser light source interferometer (for example a laser Fizeau) … Continue reading

July 23, 2019 Apre Instruments, Blog, Interferometers, Systems