Tunable filtering properties of the ployphyly photonic crystal with double local states

The mechanism of generating double defect modes in a photonic crystal with double local states is analyzed based on the tight-binding method. The optical transmission characteristic of a one-dimensional photonic crystal is studied using the transfer matrix method. And the relationship between the transmission spectrum and structural parameters of the photonic crystal is obtained. The mesoscopic calender effect is discussed when the photonic crystal is exerted on by a homotaxial stress on the basis of these theories. Therefore, a multichannel filter with a simple structure which can be modulated by the stress in the near infrared band is designed. Numerical simulation results show that the defect modes may produce a red shift with the increase of the dielectric layers' refractive index or thickness. When the uniaxial tensile stress is applied on the ployphyly photonic crystal with double local states, all defect peaks will move to the direction of the long wavelength, and the values of these defect peaks remain unchanged basically. Through numerical fitting, the relationship between these defect peaks' central wavelengths and the size of the strain produced by the homotaxial tensile stress on the photonic crystal is linear. This kind of photonic crystal filter with a simple structure has good tunability and has practical application value in the manufacture of a series of exquisite photonic crystal lasers, wavelength division multiplexers and other precision instruments.