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Research Of High-Power All-Solid-State Green And Red Lasers And The Photonic Crystals With Metamaterials

Posted on:2008-08-23Degree:DoctorType:Dissertation
Country:ChinaCandidate:H Y ZhangFull Text:PDF
GTID:1118360272985478Subject:Photonics technology
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Diode-pumped solid-state lasers (DPSL) have become main-stream of lasers in application due to their many advantages such as high efficiency, compactness, high stability, and long lifetime. They are widely used in the field of industry, scientific research, military etc. During the past few years high-power LD pumped green and red laser have become the focus of research because of their numerous applications such as laser colour display, laser medicine, high-density optical data storage, material processing, high-resolution printing, etc.Recently, metamaterials in which both permittivityεandμare negative or only one of the two parametersεandμis negative have been realized in microwave and near-infrared. When the metamaterials are introduced in one-dimensional photonic crystals, new types of photonic band gaps appear. Since the properties of such photonic band gaps are different from those of the Bragg gap, and they can lead to potential applications, one-dimensional photonic crystals containing metamaterials have become a subject of great interest for optical physics.The main contents and key creation points of this dissertation are as follows:(1) Using two GKPM-150 side-pumped laser modules, we investigated single-rod and double-rod A-O Q-switched intracavity-doubled lasers. Using a single 150W laser module with KTP crystal, we obtained 76.9W green output power with optical-optical conversion efficiency of 11.6%. Using the same module with LBO crystal, we obtained 79.3W green output power with optical-optical conversion efficiency of 18.2%. With two GKPM-150 modules in tandem with each other, double acousto-optic Q-switched and high gray track resistance KTP frequency-doubled, a laser with output power of 131W is achieved, of which the optical-to-optical conversion efficiency is 13.1%, and the power instability is 0.71% at 128W, and the beam transfer factor M2 is measured to be 6.7 at the output power of 80W. This represents, to the best of our knowledge, the advanced level so far in the respect of power stability and the beam transfer factor M2. Based on this experiment, a 120W green laser model have been accomplished which can be applied in treatment of prostate hyperplasia.(2) Using 50W, 150W side-pumped laser modules, we investigated high power continuum wave (CW) green laser with an LD side-pumped configuration and three mirror folded cavity design and KTP ofⅡ-type phase-matching for frequency doubling. Using a 50W module, we obtained 18.7W CW 532nm output power, of which the optical-to-optical conversion efficiency is 10.4%, and the power instability is 0.4031%. A prototype of cw green laser with 10-watt is made out with domestic devices. The main characteristic of it belongs to advanced level in China. Using a 150W module, we obtained 51.2W CW 532nm output power, of which the optical-to-optical conversion efficiency is 10.3%, and the power instability is 0.49%, and the beam transfer factor is measured to be better than 9 measured by knife-edge method. This represents, as far as we know, in traditional laser with rod material, this output power is ahead in the world.(3) Researches on high power continuum wave red laser. The 671nm laser reaches 1.203W when the absorbed pump power is 24.56W, with an optical to optical conversion efficiency of 4.9%. The amplitude noise is 0.52% (rms) in an hour when the output power is at about 1.08W. A double-end-pumped Nd:YVO4/LBO continuous wave laser is also achieved. We obtained 2.33W CW 671nm output power when the total pump power is 36W, of which the optical-to-optical conversion efficiency is 6.5%. The power instability is less than 0.5% at output power of about 2W with M2=3.6. The above mentioned results are ahead in the world at the respect of power stability.(4) By means of the transfer-matrix method, we investigate the transmission properties of one-dimensional (1D) photonic crystals composed of symmetrical Fibonacci sequences and heterostructures containing two kinds of metamaterials, respectively. The two types of metamaterials include negative-index materials (also called double-negative materials or left-handed materials) whose permittivity and permeability are simultaneously negative and single-negative materials whose permeability (permittivity) is negative but permittivity (permeability) is positive. The band structures of symmetrical Fibonacci sequences (SFS) composed of positive and negative refractive index materials are studied with a transfer matrix method. A new type of omni-directional zero-n gaps is found in the SFS. In contrast to the Bragg gaps, such an omni-directional zero- n gap is insensitive to the incident angles and polarization, and is invariant upon the change of the ratio of the thicknesses of two media. It is found that omni-directional zero-n gap exists in all the SFS, and it is rather stable and independence of the structure sequence. The transmission of 1D photonic heterostructures with single negative material was investigated by the transfer matrix theory. With suit parameters, the average permittivity and the average permeability is zero. A complete transmission peak exists in the forbidden gap. They are independent of incident angles and polarizations and have zero phase delay, which can be utilized to design zero-phase-shift omni-directional filters. Transmission studies for multiple heterostructures consisting of two kinds of single-negative materials inserted with defects are presented when the average permittivity and the average permeability is zero. The results show that multiple-channeled filters can be obtained by adjusting the period number m and thicknesses of defects. These structures provide an excellent way to select useful multiple-channeled optical signals from a stop gap, and it is useful in optical device applications.
Keywords/Search Tags:all solid state, high power, Nd:YAG, Nd:YVO4, 532nm green laser, 671nm red laser, intracavity frequency-doubled, A-O Q-switched, photonic crystals, negative-index materials, single-negative materials
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