In accordance with the present invention, embodiments of interferometers are presented that improves both the polarization dependency problem and helps prevents light from being reflected back into the light source, among other things. Interferometer embodiments can include an isolator coupled to a light source and polarization dependent optics coupled with the isolator to provide light to a reference arm and a sample arm, wherein reflected light provided to optical detectors is such that a polarization independent optical signal can be formed in an optical signal processor coupled to the optical detectors, and the isolator blocks reflected light from the reference arm and the sample arm from entering the light source. In some embodiments, a balanced detection system can be utilized to reduce noise.