Multi-channel near-infrared spectrometer for functional depth-resolved tissue examination and positioning applications

We present a multi-channel spectrometer that allows simultaneous acquisition of up to eight channels in order to perform parallel optical coherence tomography or low coherence interferometry. The rigid and compact design is employed in polarization sensitive optical coherence tomography measurements. Furthermore it is employed in distances and wedgeangle measurements between two glass slides. The spectrometer operates at a central wavelength of 835 nm and at a spectral bandwidth of 45 nm. This facilitates an axial resolution of 7.7 μm. The key feature is the simultaneous acquisition of up to eight channels, at a maximum frame rate of 6.5 kHz. The sensitivity is 91 dB at an integration time of 11 μs and an optical power of 0.7 mW at each of the sample arms. We obtained polarization sensitive OCT images of technical and biological samples and investigated the system inherent phase stability to multipoint low coherence interferometry measurements.