Donald L. Decker - Ridgecrest CA Paul A. Temple - Ridgecrest CA
Assignee:
The United States of America as represented by the Secretary of the Navy - Washington DC
International Classification:
G01K 1700
US Classification:
73190EW
Abstract:
A device for measuring energy absorptance of a sample material. A temperature controlled enclosure, in which a sample is suspended, is placed in an evacuated container. Calibration is accomplished by means of a known power dissipation in the sample. The sample material is irradiated by an energy beam of known power and a temperature rise is compared to the calibration temperature rise. Means for scanning the sample is also provided.
Dark Field Surface Inspection Illumination Technique
The United States of America as represented by the Secretary of the Navy - Washington DC
International Classification:
G01N 2121 G01N 2147 G01N 2188 G01J 400
US Classification:
356366
Abstract:
A method and apparatus for observing imperfections on the surface of and imbedded in an optical sample using a dark field technique. Linearally polarized laser light is entered by a prism-fluid index matching method which causes internal reflection at the critical angle. The internally reflected beam then coherently combines with the incident beam in the vicinity of the sample surface. This results in a standing wave pattern which can be adjusted by changing the laser wavelength, the angle of incidence or polarization to selectively illuminate variously regions at and below the surface. One polarization will have maximum intensity at the surface level while the alternate polarization will have a null at the surface level. Defects within the optical sample scatter light such that it does not reach the surface at an angle equal to or greater than the critical angle. This light is emitted from the sample surface and appears as a pattern of bright spots on a dark background.