Common-Path Interferometer for Endoscopic OCT

摘要

Conventional endoscopic OCT suffers from a decreased signal to noise ratio because the separated measuring and reference pathes are affected by different influences. The present invention overcomes these problems by substantially combining the reference path and the measuring path into the same optical fibre arranged in the catheter of an endoscope. The distal optics of the endoscope includes a beam splitter for splitting the incoming light beam into a measuring path directed towards a sample and a reference path directed towards a reflector. Means may be provided to alter the length of the reference path with respect to the measuring path by translating the reflector in the reference path or changing the refractive index of the reference path. Light from the reference path and from the measuring path is brought to interference by the same beam splitter and directed to a detector through the optical fibre.