Study Design Photonic Crystal Filter

Optical filter is one of the basic components of photon technology in optical communication and optical information processing has been widely used. Parameters such as the quality and volume of optical filters directly affect the value of its application.Photonic crystal has the photonic band gap frequency. A photonic crystal is an ideal natural band stop filter. And by the methods of manufacturing defect in the photonic crystal, can realize narrow-band filter Photonic crystal filter is characterized that filter performance is far superior to ordinary light filter, and in the stop band of light through inhibition can be easily reached more than30db. In addition, because of the photonic crystals are used for light waves almost no loss of dielectric materials, so the photonic crystal filter to through the band of light loss is very small. Compared with the traditional filter, filter of photonic crystal filter bandwidth can do much more, to achieve a wide range of filter. Photonic crystals with diamond structure of filtering can be done20%of center frequency, bandwidth and put forward by GuPta and others metal-medium composite photonic crystals can be from low frequency (close to zero Hertz) until the infrared electromagnetic wave filtering, this is a traditional filter hard to achieve.In addition, the current with the development of the Internet and mobile communication service, communication capacity in the field of communication is in the form of explosive growth. Therefore, how to improve the current communication capacity of telecommunication network is urgently needed to solve a problem. In low loss optical fiber has nearly30THZ huge bandwidth, usually can be used to improve the communication rate of single channel, the laying of new fiber network, increase the single core fiber channel number and other methods to improve the capacity of the optical fiber communication system. Former two methods because of restricted by technical conditions and cost factors, the development potential is not big. And the use of wavelength division multiplexing (WDM) technology and dense wavelength division multiplexing (DWDM) technology can be in a single fiber transmission multiplex communication signal at the same time, this method is currently the most effective way to improve the capacity of communication, narrow-band filter is the core component of the system.Photonic crystal as the optical waveguide devices can not only effectively guide light transmission, can also be used to point defect and line defect preparation WDM devices based on photonic crystals, to realize more functions. WDM devices based on photonic crystal has a simple structure, good signal, low cross interference, etc. And in the optical frequency range, the size of the photonic crystal lattice, generally in the sub-micron, is helpful to realize the miniaturization of optical devices. Therefore, the use of photonic crystal manufacturing optical frequency range of WDM filter caused a high attention to science and technology workers.Is the purpose of this paper to design photonic crystal filter research, combining the domestic and foreign research results and experience, through changing the structure of the photonic crystal microcavity, improve micro cavity quality factor (Q), and makes certain frequencies of light in the micro cavity to form a standing wave and light field intensity distribution of the photonic crystal cavity is gaussian shape, then near the microcavity waveguide design, through the waveguide will certain frequencies of light separated from light source, so as to realize narrow-band filter, effectively guide the light transmission, and provide the theoretical reference to improve the communication capacity of optical fiber.