Patent ID: 7352466

Claim:
A device for detecting presence of a gas having a specific absorption wavelength, the device comprising: a photonic crystal cavity configured to sample a gas and receive light, wherein the light passes through the photonic crystal cavity, and wherein the light has a wavelength that at least partially falls within the specific absorption wavelength of the gas; a detector to detect the light after passing through the photonic crystal cavity; a generator configured for generating at least one parameter of a band gap spectrum from at least a portion of the light passing through the photonic crystal cavity, wherein the generator is configured to perform a numerical simulation within a frequency range of the photonic crystal cavity to generate a set of spectral response data points, and wherein the generator performs rational function interpolation on the set of spectral response data points to generate a spectral response of the photonic crystal cavity, and wherein the generator determines at least one parameter representing the band gap spectrum from the spectral response of the photonic crystal cavity; and a comparator for comparing the at least one parameter of the generated band gap spectrum with stored parameters of band gap spectrums, wherein a match of parameters indicates a presence of the gas.