Compact Spectroscopic Sensor Using an Arrayed Waveguide Grating

We have previously proposed a compact spectroscopic sensor based on the arrayed waveguide grating (AWG) which makes use of wavelength multi/demultiplexer in a photonic network. We constructed a new planar sensor using a visible AWG for spectroscopic sensing of absorption characteristics with multiple dicing grooves for accommodating a liquid sample. A parabola-shaped sample injection waveguide effectively improves sensitivity because diffraction loss in the direction of its substrate is reduced. In this manuscript, discrimination between chlorophyll a and b as test samples is to be investigated using our AWG spectroscopic sensor.