  We demonstrate a new kind of optical spectrometer employing photonic crystal
patterns to outcouple waveguided light from a transparent substrate. This
spectrometer consists of an array of photonic crystal patterns, nanofabricated
in a polymer on a glass substrate, combined with a camera. The camera captures
an image of the light outcoupled from the patterned substrate; the array of
patterns produces a spatially resolved map of intensities for different
wavelength bands. The intensity map of the image is converted into a spectrum
using the photonic crystal pattern response functions. We present a proof of
concept by characterizing a white LED with our photonic crystal spectrometer.
