Abstract As standard concepts for precision positioning within a machine reach their limits with increasing measurement volumes, inverse are promising approach addressing this problem. The principle entails other limitations, as high-precision of sensor head large volume, three four-beam interferometers required in order to measure all necessary translations and rotations the reconstruct topogr...

In this paper a method for digitally recording four quarter-reference-wave-holograms (by CCD) in a Mach-Zehnder interferometer setup, and reconstructing the object wave-front by numerical method is presented. The terms of direct transmission, auto-correlation and conjugate wave in the four wave reconstruction are cancelled out and only one original object wave is left after overlapping. Reconst...

A method for detection of thermal infrared radiation from astronomical sources is discussed from an instrumentation point of view. This method utilizes heterodyne detection, whereby light collected by a telescope is spatially mixed with single-mode radiation from an infrared laser local oscillator onto a HgCdTe photodiode. The operating wavelength range of the receiver is adjustable from approx...

Acousto-optic (AO) is an emerging hybrid technique for measuring optical contrast in turbid media using coherent light and ultrasound (US). A turbid object is illuminated with a coherent light source leading to speckle formation in the remitted light. With the use of US, a small volume is selected,which is commonly referred to as the "tagging" volume. This volume acts as a source of modulated l...