Patent ID: 6590668
Filing Date: 2003-07-08
Classification: G01J

Abstract:
A method for a direct phase-angle measurement of radiation (2) passing through a body (3), comprising the steps ofexposing the body (3) to coherent radiation (2) of pre-determined frequency, imaging radiation passing through the body (3) by an imaging optical system (6) in an image plane (7) in which a sensor (8) is located and possessing a diaphragm (11, 19) having at least one aperture (20), positioning one of a wedge (14, 23), or folding wedges (16, 24) or two tilted parallel plates (17, 18, 25, 26) adjacent the diaphragm (11, 19), positioning at least one lens element (9, 19) on a side of the wedge (14, 23), or folding wedges (16, 24) or tilted plates (17, 18, 25, 26) opposite said diaphragm (11, 19) or on a side of said diaphragm (11, 19) opposite the wedge (14, 23), or folding wedges (16, 24) or tilted parallel plates (17, 18, 25, 26), superimposing a reference radiation which has been generated in accordance with a shearing method upon the sensor (8), and determining phase of the radiation (5) from the body (3) by measurement signals of the sensor (8).