Patent ID: 7388672

Claim:
An interferometer for use in an optical coherence tomography (OCT) system comprising: a light source; a first 2×2 coupler having four ports; a second 2×2 coupler having four ports, with light from the source being coupled to a first port of the first coupler, with the first coupler dividing the light between a sample path and a first portion of a reference path, with the light exiting the first coupler into the sample path from a second port and, after scattering from the sample, returning to a second port of the second coupler and with the light exiting the first coupler into the first portion of the reference path from a third port and entering the second coupler via a first port, with the light exiting the second coupler into a second portion of the reference path from a third port and returning to the second coupler via said third port; a first detector for receiving light returned from both the sample and the reference paths via a path through the first port of the second coupler and a fourth port of the first coupler and generating first output signals in response thereto; and a second detector for receiving light returned from both the sample and the reference paths via a fourth port of the second coupler and generating second output signals in response thereto, said first and second output signals containing information about the light scattering properties of the sample.