Patent ID: 7876450

Claim:
A method for performing interferometric analysis of an object, comprising: (a) producing a beam of coherent laser light with circular polarization; (b) passing the light through a non-polarizing beamsplitter; (c) using a partial reflector to collinearly reflect a portion of the beam, which is used as the reference beam, and to transmit another portion of the beam; (d) passing the transmitted light through a linear polarizer; (e) focusing the transmitted light onto the object; (f) directing light scattered from the object through the linear polarizer and through the partial reflector, where the scattered light recombines with the reference beam to form a recombined beam; (g) passing the recombined beam through a polarizing beamsplitter to form two split beams; (h) detecting each of the split beams with a split detector to produce differential interferometric signals; and (i) performing the interferometric analysis in accordance with the differential interferometric signals; wherein the object is contained in a microfluidic channel in a wafer.