Polarization-based balanced detection for spectral domain polarization sensitive optical coherence tomography

We introduce a spectral domain polarization sensitive optical coherence tomography system with balanced detection capability. The design relies on polarization optics to split incoming light into reference and sample paths. Modified light returning from these paths creates the co- and cross-polarization channels, which are respectively coupled into two polarization-maintaining fibers. These fibers carry the light to a custom spectrometer, and their orthogonal axes help form the interference. The spectrometer produces two pairs of highly aligned and focused spectral lines on a camera for optimal balanced detection operation. System performance is characterized and demonstrated for biomedical imaging with improved signal-to-noise ratio.