Ultra-wide band (400-1700nm) integrated spectrometer based on arrayed waveguide gratings for spectral tissue sensing

Photonic Integrated Circuits (PIC) find increasing use in applications that rely on wavelengths outside of the telecommunication wavelength bands where they originate from. Spectroscopy applications in life science and medical generally use wavelengths covering the full visible, near and short-wave infrared region. In this paper we describe the use of photonic integrated circuits as a spectrometer for spectral tissue sensing, which requires to measure the spectral response of a broad band source, emitting light from 400 to 1700nm, scattered from the tip of a photonic needle that is in close contact with tissue [1-4]. The detected spectral fingerprints in the scattered light enables to distinguish between different tissue constituents and tissue types and may serve as real-time feedback to a physician during an intervention. Using photonic integrated circuits supports the desire to lower the size and increase the usability of such equipment, making it more portable and on the long run even implantable.