Patent ID: 7804069
Filing Date: 2010-09-28
Classification: G01N

Abstract:
1. A method for imaging a sample, the method comprising: a) irradiating the surface of a sample with a source of coherent substantially monochromatic and substantially continuous radiation from a non-pulsed source with a frequency in the range 25 GHz to 100 THz, said radiation having at least one characteristic feature present in said radiation before said radiation irradiates the surface of the sample, said at least one characteristic feature being varied between successive cycles of radiation such that successive cycles of radiation from said non-pulsed source are distinguishable from one another; b) detecting said radiation reflected from the sample; c) providing and detecting a probe beam having a phase related to that of the radiation leaving the source; and d) analyzing the detected radiation for said at least one characteristic feature within the radiation and measuring any shift in the position of said at least one feature in the reflected radiation in order to derive structural information about the sample as a function of depth from the surface of the sample.