Study on photonic crystal filter for detecting the stimulated scattering signals in atmosphere

Through the analysis of the scattering characteristic when the laser transmit through the atmosphere, the bandwidth and the center wavelength of Brillouin, Rayleigh scattering and the vibrational Raman scattering of nitrogen are especially discussed in the paper. Based on the parameters mentioned above, the required structure of the photonic crystal filters for detecting the scattering signal are obtained. A photonic crystal filter is designed for detecting the atmospheric stimulated scattering signal by the optical transfer matrix method (TMM).The results show that the optical transmittance at the center wavelength is higher than 99%, and the center wavelength can be easily shifted to the central of the scattering spectra by selecting suitable parameters. There is a strict demand of the incident angle to the photonic crystal for detecting the Brillouin scattering signal, and the signal can not be well detected if there is a tiny shift of the angle. With the incident angle varies from 0deg to 3deg for the photonic crystal filters, the Rayleigh and the vibrational Raman scattering signals can still be well detected.