Zero Reflection Characteristics Of The Light In Asymmetric Multilayer Photonic Crystals

Optical Tamm states(OTSs) were first named by Russian and French scientists in 2005, which is in analogy with Tamm surface states in solid-state physics. Different from the traditional surface plasmons, OTSs can be excited in both TE and TM polarizations, and can be excited within the cone of light. The potential applications of OTSs have been proposed in recent years such as optical sensors, optical resonance filters, polarization lasers, optical switches and one-way transmission devices, etc. The optical absorbers based on OTSs and F-P resonances have drawn extensive studies. If the microstructures contain the loss material and are asymmetric, one-way absorption or reflection can be realized. In recent years, nonreciprocal perfect absorbers have been reported theoretically, which have the important potential applications such as one-way absorbers and optical diodes etc. Moreover, the complete transmission of the light are reported theoretically in asymmetric microstructures. Such researches are important to understand the propagation characteristics of the light in the asymmetric microstructures.By means of transfer-matrix method, this thesis investigates the propagation characteristics of the asymmetric composite periodic structures consist of the metals and transparent dielectrics.In chapter 2, we mainly made the experimental investigation of multichannel nonreciprocal perfect absorption in asymmetric sandwiched structures composed of metal films and truncated dielectric photonic crystals. The tunable multichannel perfect absorbers with the asymmetric metal-photonic crystal hetero-structure were studied theoretically in previous years. In this chapter, using the electron beam evaporation, magnetron sputtering and ion beam assisted deposition techniques, we made the relevant optical experiments. It is found that one-way multichannel perfect absorption peaks can be realized by changing the number of basic units in photonic crystals and suitable thicknesses of the metal films. Moreover, the physical mechanism of the perfect absorption is investigated by the electromagnetic field distribution at the absorption wavelengths. Such structures are important for fabricating new kind of optical devices.In chapter 3, the complete transmission characteristics in asymmetric one-dimensional photonic crystals is studied theoretically and experimentally. The asymmetric structure is composed of two truncated dielectric photonic crystals. When the defect mode in one photonic crystal and a transmission peak in the other have the same wavelength and unit transmission, a perfect transmission peak can be realized in the heterostructure composed of two different photonic crystals. The optical experiment is by the electron beam evaporation, and the experiment results are in excellent agreement with numerical simulations. These researches are significant to understand the perfect transmission in the asymmetric photonic microstructures.