System for Performing Dual Path, Two- Dimensional Optical Coherence Tomography(OCT)

Abstract

Apparatus and methods are described for optically analyzing an object having a plurality of layers, without needing to use a reference mirror. Light is generated using an extended broadband light source. The light is directed toward the object, such as to create respective images of the light source on the respective layers of the object. Light that is reflected from a point of the object is gathered into a conjugate point in a detector. The thicknesses of the plurality of layers at the point of the object are determined, by analyzing, within the gathered light, interference between light reflected from the plurality of layers of the object at the point. Other applications are also described.

1 . A method for optically analyzing an object having a plurality of layers, without needing to use a reference mirror, the method comprising:
 generating light using an extended broadband light source;   directing the light toward the object, such as to create respective images of the light source on the respective layers of the object;   gathering light that is reflected from a point of the object into a conjugate point in a detector; and   determining the thicknesses of the plurality of layers at the point of the object, by analyzing, within the gathered light, interference between light reflected from the plurality of layers of the object at the point.   
     
     
         2 . The method according to  claim 1 , wherein the object includes a portion of an eye selected from the group consisting of: an intra-ocular lens, a retina, a cornea, and a tear film, and wherein directing the light toward the object comprises directing the light toward the selected portion of the eye. 
     
     
         3 . The method according to  claim 1 , wherein determining the thicknesses of the plurality of layers at the point of the object comprises analyzing the interference between light reflected from the plurality of layers of the object at the point as being proportional to an autocorrelation function of the object's structure at the point. 
     
     
         4 . The method according to  claim 1 , wherein:
 gathering light that is reflected from a point of the object into the conjugate point in the detector comprises gathering light that is reflected from a plurality of points of the object into respective conjugate points in the detector; and   determining the thicknesses of the plurality of layers at the point comprises determining the thicknesses of the plurality of layers at the plurality of points of the object, by analyzing, within the gathered light, interference between light reflected from the plurality of layers of the object at the respective points.   
     
     
         5 . The method according to  claim 1 , wherein determining the thicknesses of the plurality of layers at the respective points of the object comprises analyzing the interference between light reflected from the plurality of layers of the object at the respective points as being proportional to an autocorrelation function of the object's structure at the respective points. 
     
     
         6 . The method according to  claim 1 , wherein gathering light that is reflected from the point of the object into the conjugate point in the detector comprises gathering light that is reflected from the point of the object into a conjugate point in a spectral imaging camera. 
     
     
         7 . The method according to  claim 6 , wherein gathering light that is reflected from the point of the object into the conjugate point in the spectral imaging camera comprises gathering light that is reflected from the point of the object into a conjugate point in a hyperspectral camera. 
     
     
         8 . The method according to  claim 1 , further comprising modulating a spectrum of the light generated by the light source over time, such that the light that is directed toward the object varies spectrally with time, using a light modulator. 
     
     
         9 . The method according to  claim 8 , wherein the light modulator includes an interferometric system, and wherein modulating the spectrum of the light generated by the light source over time comprises modulating the spectrum of the light generated by the light source over time using the interferometric system.