Patent ID: 6323949
Filing Date: 2001-11-27
Classification: G01P,G01S

Abstract:
An apparatus for the determination of a condition or state of an object based on quasi-elastic interaction between the object and light transmitted to the object, comprising:a) a light source for emission of light,b) a beam transmitter illuminated by the light source and including a diffractive optical element further including a diffracting region still further including a first transmitting diffracting structure for transmission of a first light beam to the object and a second transmitting diffracting structure that is laterally displaced relative to the first diffracting structure for transmission of a second light beam to the object, wherein the first and second transmitting diffracting structures emit the first and second light beams with corresponding axes which are at least substantially parallel and have a distance between them that is substantially independent of a wavelength of the light emitted from the light source,c) a receiver for collecting and detecting light that has interacted with the object said receiver including at least one light detector, andd) a processor operatively connected to the receiver for determining the condition or state of the object based on the detected light,wherein the determination of the condition or state of the object is substantially exclusively defined by the location of the first and second transmitting diffracting structures and substantially independent of the wavelength of light emitted from the light source and the object.