Patent ID: 7872757

Claim:
An apparatus for tracking a phase of at least one electro-magnetic signal associated with at least one portion of a sample, comprising: a) a detecting arrangement obtaining at least one first interferometric signal comprising a plurality of spectral bands separated from the at least one electro-magnetic signal; b) a phase modulator driver having a modulating frequency, and configured to modulate the at least one first signal based on the modulating frequency so as to generate at least one second signal; c) a mixer configured to mix the at least one first signal with the at least one second signal so as to generate a resultant signal; and d) a processing arrangement configured to (i) generate an offset based on the resultant signal, (ii) control a phase of the at least one first signal based on the offset to generate further information, and (iii) generate an image based on at least a portion of the sample using the further information.