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Theoretical Calculation Of Photonic Crystals And Experimental Research Of A Dual-wavelength Laser

Posted on:2006-05-27Degree:MasterType:Thesis
Country:ChinaCandidate:H LiuFull Text:PDF
GTID:2178360182976581Subject:Physical Electronics
Abstract/Summary:PDF Full Text Request
This paper is divided into five chapters. The main contents of the former fourchapters include the summarization of photonic crystals and the theoretical calculationof some aspects of photonic crystals. The experimental study of a dual-wavelengthcontinuous wave (cw) diode-side-pumped Nd:YAG laser is discussed in the fifthchapter.In 1987, a remarkable step was made by Yablonovitch and John, who pointed outa new conception--photonic crystals. Photonic crystals are a new type of syntheticmicrostructure materials which have periodical refraction index variations in the spaceand produce photonic band gaps similar to electronic band gaps produced by thesemiconductors. Photonic crystals have many potential applications due to theirunique abilities to manipulate and control photon behaviors. In recent years, intensiveresearch efforts have been devoted to the studies of photonic crystals.The contents of the former four chapters are shown as follows:1) Present a brief introduction to the photonic crystal basics and some primarycharacteristics. Some major fabrication methods are demonstrated and variousapplications of photonic crystals such as photonic crystal fiber, photonic crystalwaveguide, photonic crystal laser, superprism and so on, are also discussed in detail.2) Compared with the semiconductor and micromachining fabrication techniques,the holographic lithography method offers a number of advantages. In this study, amulti-beam interference model is proposed for predicting two-and three-dimensionalphotonic crystal structures through designing various parameters of the beams, suchas beam intensities, polarization directions, phase delays and so on. Above calculatedresults provide some beneficial analyses and predictions in advance for choosingproper optical parameters to fabricate two-and three-dimensional photonic crystalstructures through the holographic lithography method under laboratory conditions.3) According to the electromagnetic wave theory of three-dimensional photoniccrystals and plane wave expansion method, give a complete deduction for Bloch wavesolution and also offer the academic foundation of the existence of band gap. Take thetwo-dimensional photonic crystal of square lattice for instance, and deduce theintrinsic equations of TE mode and TM mode using plane wave expansion method.4) Based on plane wave expansion method, the influence of three factors such aslattice structure, dielectric constant ratio, and filling ratio on two-dimensionalphotonic crystals with square and hexagon structures, and three-dimensional photoniccrystals with fcc, diamond and woodpile structures is studied. These calculated resultsand analyses provide a useful guide and a theoretical basis for the latter preparationand application research of photonic crystals. In this paper, some interestingphenomena that were not noticed in the former papers are also presented.The experiment of a diode-side-pumped Nd:YAG all-solid-state laser which canrealize the simultaneous dual-wavelength operation is reported in the fifth chapter.Through controlling the coating reflectivities and the intracavity diffraction losses ofdifferent waves, a dual-wavelength cw diode-side-pumped Nd:YAG laser thatoperates at 1064nm and 1319nm simultaneously is investigated. The relationshipbetween the ratio of the output power of 1064nm laser to that of 1319nm laser and thelength of 1064nm resonant cavity is analysed. The experimental results verify thefeasibility that the dual-wavelength cw output can be achieved by use of a four-mirrorcavity. When the pumping power is 500W, the dual-wavelength cw average outputpower reaches as high as 45W and the respective cw output power exceeds 20W.These experimental results are the highest record as far as we know.
Keywords/Search Tags:photonic crystal, photonic band gap, laser holography, multi-beam interference, plane wave expansion method, dielectric constant ratio, band gap ratio, LD-pumped, dual-wavelength laser, Nd:YAG
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