| Lasers of 3-5 micrometers in mid-infrared atmosphere window and 8-14 micrometers in far-infrared atmosphere widow can be made use of to infrared tracing, searching target navigation and optical remote sensing, which has significant meaning for state security. Various kinds of gas, dye, solid and semiconductor lasers have covered the regions from ultra-violet to around 1.55 micro meters for communication. However, the wavelength of semiconductor laser which is usually used at long wavelengths depends on the width of band gap. But semiconductor material the band gap of which is located in mid-infrared or far-infrared regions is quite scarce, which retards the development of min-infrared and far-infrared lasers. Highly efficient emitting source and laser working in mid-infrared region is seriously lacking. Many important needs cannot be satisfied. To name a few, mid-infrared wavelength is the most important region for detecting characteristic peaks of toxic gas and mid-infrared lasers for atmosphere pollution inspection is demanded. The emergence of quantum cascade laser exploiting band transition emitting has made some breakthrough in some extend. Scientists of our country have conducted splendid research. But in general, the research of highly efficient sources is far from reaching a satisfactory status.Photonic crystals are also called photonic band gap materials. Its classical structure possesses three-dimensional periodical refractive index variation. For some lattice types like FCC and diamond structures, if the refractive index of structure material which consists photonic crystal is far enough from that of background material, photonic crystals will show some unique band structures which common semiconductors don't possess. Through the precise control of band gaps to photon emission and transmission, brand new photon and photon-electron components like micro-cavity lasers, photonic crystal waveguides, photonic crystal micro antennas, photonic crystal fibers and photonic crystal super lens and realized. Modulation of lattice periodicity can make photonic crystals work in different electromagnetic regions.The research purpose of this dissertation is making use of photonic gap effect to modulate the emission of thermal radiation source. To be specific, we employed materials with higher infrared emission capability to fabricate photonic crystal structures and modulated the emission through photonic crystal band gap structure. As we all know, some metallic materials have relatively higher melting point, and the peak of wide infrared emission profile blue-shifts with the increase of heating temperature. If these metals with high melting points can be used as structure materials of photonic crystals and the match of photonic gap and infrared emission peak can be realized, highly efficient emission in a certain narrow wavelength range might be realized. This dissertation takes metal as structure material for realizing mid-infrared source. Through reabsorbing photons by metal at certain wavelength to avoid energy loss and making use of enhanced reflectivity effect at the band gap edge to confine energy release of heated metallic nanometer shell photonic crystal in a narrow wavelength range, radiation enhancement can be achieved.In the aspect of thermal emission, it has been demonstrated in experiment that the metal layer in photonic crystal can be used to enhance infrared light emission. In order to effectively confine and modulate radiation signal, the emission source which is the metallic photonic crystal we fabricate has to be three dimensional. This poses a great challenge to fabrication technique. Especially, appropriate manufacturing technique for complicated metallic photonic crystals is lacking, which stands in the way of research on thermal emission modulation by metallic photonic crystals.To solve this problem, this dissertation adopts a method which can fabricate arbitrary complicated three dimensional polymer-metal, core-shell photonic crystals. To be specific, we first applied femtosecond laser two-photon polymerization technique to fabricate the polymer framework of three dimensional photonic crystals, and then plated a uniform layer of metal on the surface of polymer framework through chemical plating technique. Thanks to the capability of precise fabrication of nearly arbitrary structures possessed by femtosecond laser micro-nanofabrication technique, we can appropriately design photonic crystals of any structure in order to fully make use of photonic crystal band gap effects. And the reason of choosing chemical plating method to complete the fabrication of metallic nanometer shell is that chemical plating performs good in preserving shapes, which is suitable for metalizing our complicated three dimensional structures. It can form a consecutive and condensed coating on the surface of complicated structures. What is more important is that it can perform metal depositing on insulating dielectric materials after preprocess of sensitizing and activation. This kind of workmanship combining two-photon polymerization micro-nanofabrication technique and metalizing surface through chemical plating tackles the problem of fabricating three dimensional metallic photonic crystals. Besides, metallic microstructure fabricated is high in quality. The structure design is flexible and the process is relatively simple. These lay a good foundation for research on the properties of complicated three dimensional metallic microstructures. This dissertation conducted the study on modulation thermal emission in mid-infrared wavelength range by metallic microstructures. The detailed work comprises several aspects as follows:In this dissertation, we firstly used femtometer laser micro-and nano-fabrication technology to fabricate sphere and club structured photonic crystal of to mimic the real atomic lattice structure. The spheres represent the atoms in atomic crystal and the clubs have supporting and connecting effects. Then we measured the reflection and transmission spectra to show the gap effect. In the experiments, we didn't only fabricate basic lattice structure like cubic, fcc, bcc structures, but also systematically studied the photonic crystal structure and photonic gap property of diamond along<111>,<110>,<100>directions. The results matched the theoretical calculations perfectly. Similar to the doping effect in semiconductors, if we bring some random state into photonic crystal, in other words, introduce some defects in the periodical structure, there will be some defect modes in the photonic gap. Due to the confinement of photons in the defect modes, we can get highly localized electromagnetic wave energy and generate enhanced photonic density of states. Through this characteristic, we can enhance non-linear optical effects and suppress spontaneous emission, etc. In this dissertation, we designed and fabricated a complete 5-layer graphite structured photonic crystal. We elongated the pillars of the middle layer and successfully introduced a defect. In this structure which has photonic gaps at both sides of the defect, multi-reflection happens. As a resonult, a plane micro-cavity is formed and micro-cavity resonance has been generated. We use transmission matrix method to theoretically simulate and verify the photonic band gap of complete graphite structure and the micro-cavity resonance property of graphite structure with defects. The calculated reflectivity matches the peak measured in the experiment test very well and further proved that the defect brought into the graphite structure generates a defect mode and localized photon state is realized. The femtosecond laser micro-and nano-fabrication technology doesn't only expand the variety of photonic crystals, but also deepens the understanding of photonic crystals through comparing photonic crystals with corresponding atomic crystals.Then this dissertation studies the process of realizing metallic surface through chemical plating on polymeric photonic crystal template surface. Electricity-free plating technology is very good for shape preserving, which is very suitable for metalizing complex three dimensional structures. It can form consecutive and compact plating layer on complex structure surface. What is more important is that it can realize metal deposit on insulating dielectric material surface through sensitization, activation and other pretreatments. In this dissertation, we systematically discuss the chemical silver-plating and Ni-plating experiment technique, and successfully realize the metal deposit on diamond and graphite structured polymeric template surface. At the same time, we conducted study on the thermal stability of two deposited metal material. For chemical silver-plating structure, the structure can't hold in the 300 degree centigrade heating condition. The thermal stability is not good.Although microstructured surface after chemical silver-plating doesn't satisfy the technique requirement of thermal radiation source, silver, as a very good material in extent of optical property, pocesses the plasmon resoncance absorption peak and has a lot of applications in optical components. This kind of metallic structure possesses complete photonic band gap potential and has great significance in integrated optics. The Ni photonic crystal has better thermal stability. Under 500 degree centigrade, the structure maintains stable and begins to collapse when heated to 600 degree centigrade. At the same time, we discuss the influence of deposited layer's thickness on thermal stability of the structure. The thermal stability of the Ni microstructure can fullfil the technique requirement of thermal radiation source. And studing low temperature thermal radiation source property has more important value in pratical application.In the last part of the dissertation, we study the control of chemical plating Ni shell graphite structured photonic crystal on thermal emission. We first measured the reflectivity and aborptivity spectra of Ni graphite-structured photonoic crystal. Due to the group velocity slow-down at the band gap edge, the light-matter interaction enhances. As a result, we mesured two obvious absorption peaks at the photonic band gap edges. The enhancement of aborption peaks indicate the possibility of thermal emission control. We conducted thermal emission spectra measurment at heating temperature of 370℃,400℃,450℃,500℃,530℃for the graphite-structured Ni photonic crystal. The two emission peaks matched perfectly with the absorption peaks of graphite structure, which shows that the thermal emission comes from the propagation band of the photonic crystal. At the same time, with the increase of temperature, the peak value increases and the peak positions don't change with the temperature. Compared to the black-body radiation, the thermal radiation of metallic micro-structured photonic crystal has obvious direction characteristics which correspond to absorption peaks.Through the study of thermal emission of metallic photonic crystal, we can conclude that, for our metal shell photonic crystal, we can determine the positions of absorption peaks through density of states enhancement at the band gap edge based on photonic crystal band gap position and further complete the modulation of thermal radiation. The components fabricated by us are small, highly efficient and have wide application prospects. At the same time, through our dissertation, the design of almost abitrary complex three dimenstional structured polymeric photonic crystal can be done. And with help of electricity-free plating, the metallic photonic crystal can be fabricated. The study of metallic shell photonic crystal will pave the road of future research on metallic photonic crystal based surface plasma polariton components and surface plasma polariton enhanced Raman scattering.
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