Absolute distance metrology for space interferometers

Future space missions, among which the Darwin Space Interferometer, will consist of several free flying satellites. A complex metrology system is required to have all the components fly accurately in formation and have it operate as a single instrument. Our work focuses on a possible implementation of the sub-system that measures the absolute...

Absolute distance metrology for space interferometers

Space interferometers consisting of several free flying telescopes, such as the planned Darwin mission, require a complex metrology system to make all the components operate as a single instrument. This metrology system consists of various sub-systems to monitor distances, angles and speeds. Our research focuses on one of these sub-systems that...

In-process measurements of material removal in fluid jet polishing

A prototype of a system for in-process monitoring of material removal in fluid jet polishing (FJP) is presented. The measurements make use of temporal phase unwrapping (TPU) allowing for a large working range. The measurement system will be discussed, with all problems that had to be overcome like water on the surface and vibrations, as well as...

Applicability of iTIRM for roughness reduction monitoring

The results obtained with iTIRM during polishing are presented. It is shown that iTIRM unites the working ranges of several other techniques where iTIRM can be used during production where the others can not. The applicable range of iTIRM is shown to be at least 1 um down to 0.1 nm rms.

In-process monitoring of grinding and polishing of optical surfaces

A new tool with which to monitor the quality (roughness and subsurface damage) of optical surfaces during grinding and polishing, intensity-detecting total internal reflection microscopy (iTIRM), is presented. A general description of the new measurement method is given, followed by a description of the experimental in situ measurement setup....

Quantitative roughness measurements with iTIRM

A new method, iTIRM, is used for quantitative surface roughness measurements of ground and polished surfaces and it is shown to be a useful tool for measuring total surface quality instead of individual roughness parameters.

In-process monitoring of transition from brittle to ductile mode grinding

iTIRM: A nondestructive measuring technique to monitor surface quality during grinding and polishing

A new measurement method, called iTIRM, is presented. It is capable of measuring the surface quality, roughness and subsurface damage, of optical surfaces in a nondestructive way. Measurements have been carried out and are presented, showing the capability of iTIRM to quantify the quality of optical surfaces and to localize surface defects. The...

Application industrielle de ITIRM pour visualiser et mesurer la qualité de surface lors de la fabrication de composants optiques de haute qualité

iTIRM est une nouvelle méthode quantitative pour mesurer la qualité de surface des composants optiques. A cause de son caractère non destructif, il est possible d'utiliser iTIRM pour contrôler la qualité de surface lors des procédés de doucissage et de polissage. Par conséquent, iTIRM est un outil pratique pour l'amélioration ou le développement...

Study of blast wave interactions with structures using a phase-stepped double reference beam holographic interferometer

An optical study of blast wave propagation and interaction with multiple structures is presented, as well as a method for obtaining quantitative information on the pressure distribution from a number of phase-stepped images. The blast load distribution on buildings is studied by scaling down the buildings and exposing to a plane shockwave in a...