Results 161 to 170 of about 13,727 (206)

A new interferometric alignment technique

Applied Physics Letters, 1977
A new interferometric alignment technique has been developed that is suitable for aligning x-ray lithography masks or photomasks relative to a substrate. A superposition precision of 200 Å has been demonstrated and in principle ∼100 Å should be possible.
D. C. Flanders, Henry I. Smith, Stewart Austin   +2 more
openaire   +1 more source

Comparison Of Interferometric Contouring Techniques

SPIE Proceedings, 1989
Projected fringe contouring, projection moire, shadow moire, and two-angle holographic contouring all measure surface height relative to a reference surface. A single theory can be used to describe all of these techniques. This paper compares these techniques with each other and with conventional interferometry.
Katherine Creath, James C. Wyant
openaire   +1 more source

Dual-wavelength interferometric technique with subnanometric resolution

Applied Optics, 2002
A new fringe subdivision method that employs a large synthetic wavelength to subdivide fringes formed by a small single wavelength is proposed. Based on this subdivision method, we demonstrate a novel dual-wavelength interferometric technique with subnanometric resolution, whose potential fringe subdivision factor derived from an evaluation of the ...
Benyong, Chen, Xiaohui, Cheng, Dacheng, Li   +2 more
openaire   +2 more sources

Advanced interferometric techniques for monitoring urban areas

2009 Joint Urban Remote Sensing Event, 2009
This paper addresses techniques for the imaging and monitoring of urban areas via advanced interferometric analysis. We discuss the multidimensional SAR imaging techniques and an approach for the generation of long term time series from multisensor data. Results of the application to real ERS and Envisat data are presented.
Bonano M, Fornaro G, Lanari R, Manunta M, Reale D, Serafino F   +5 more
openaire   +4 more sources

Imaging through scattering media by interferometric techniques

Applied Optics, 1981
Imaging through scattering media such as fog is a problem with few known viable solutions. Holographic techniques have been demonstrated successfully in the laboratory, but their usefulness is often limited in field conditions by the requirement of a separate coherent reference beam.
A M, Tai, C C, Aleksoff, B J, Chang
openaire   +2 more sources

Specialized Interferometric Testing Techniques

Workshop on Optical Fabrication and Testing, 1981
With higher and higher demands put on the performance of optical systems today, there has been a trend toward using nonspherical surfaces in these systems. Optical metrology is given the responsibility for testing these surfaces. Fortunately, many of these surfaces can be tested in a straightforward manner.
openaire   +1 more source

Novel Unambiguous Interferometric Technique for Surface Inspection

CLEO/Europe Conference on Lasers and Electro-Optics, 1998
We describe a new interferometric technique using polarisation measurements which eliminates the need to count fringes, giving an unambiguous measurement of surface height. Applicable to the whole image, the height of each pixel element is determined independently without the need for scanning optical components.
J. P. Lesso, A.J. Duncan, W. Sibbett, M. J. Padgett   +3 more
openaire   +1 more source

The interferometric strain rosette technique

Experimental Mechanics, 1996
An interferometric strain rosette can be used to measure three in-plane strains. The strain rosette consists of three microindentations produced on an object surface. Upon illuminating the indentations with laser light, each pair of indentations acts as a two-point source generating a pair of Young's interference fringe patterns.
openaire   +1 more source

A Bayesian Filtering Technique for SAR Interferometric Phase Fields

IEEE Transactions on Image Processing, 2004
SAR interferograms are affected by a strong noise component which often prevents correct phase unwrapping and always impairs the phase reconstruction accuracy. To obtain satisfactory performance, most filtering techniques exploit prior information by means of ad hoc, empirical strategies.
POGGI, GIOVANNI, FERRAIUOLO, GIANCARLO
openaire   +3 more sources

Low Coherence Interferometric Technique

2001
We propose an original technique based on low coherence interferometry to detect objects in strongly scattering media. In order to use broadband light, a special interferometer called the SISAM correlator is used to allow coherent superposition of the reference and tested beams.
G. Brun, I. Verrier, K. Ben Houcine, C. Veillas, J. P. Goure   +4 more
openaire   +1 more source