According to the theory of acousto - optic ( ao ) interaction , the formulas of diffraction loss of two ao q - switches , which acousto - field are perpendicular or parallel one another , the power divider for ensuring two ao q - switch synchronization and effective power driving is designed . the calculation results are satisfied with nd : yag laser experimental results . it is show that two ao q - switches , which acousto - field are perpendicular each other , switch - loss is nearly one times larger than one ao q - switch , one of third larger than the two ao q - switches which acousto - field are parallel 从理论上对声光器件衍射损耗作了分析与计算，研究了二维双声光器件对提高衍射损耗效率的影响，在实验中采用二维双声光组合器件提高声光器件的对nd ： yag激光器的关断能力，较之单声光的关断能力提高了一倍左右，而对于平行双声光也提高了30左右，并设计了声光驱动功率分配器以驱动双声光器件达到同步，消除了激光输出的多脉冲现象，提高了脉冲列的输出功率。
Ytterbium ( yb ) - doped silica fibers have a broad - gain bandwidth ( 850 ~ 1050nm ) , excellent power conversion efficiency , and a broad - absorption bandwidth ( 900 ~ 1200nm ) . their ability to provide amplification over the very broad wavelength range from ~ 975nm to ~ 1200nm is expected to generate increasing interest in the near future . they offer an almost ideal gain medium for the fiber lasers and fiber amplifiers that work at the wavelength around 1 m 掺镱石英光纤具有几个方面的优点,如能级结构简单,与掺er3 + 、 nd3 +等稀土离子的光纤相比,不存在对泵浦光或信号光的激发态吸收( esa ) ,可以有更高的掺杂浓度;有较宽的吸收光谱( 850 ~ 1050nm ) ,可以利用多种泵浦光源来设计泵浦方案;辐射光谱宽( 900 ~ 1200nm ) ,激光输出波长可以有很宽的可调谐范围。
According to the guidline , two nd : yag lasers have been designed and set up , one is end - pumped by lower output power ld using a selfoc micro lens , and the other is end - pumped by high output power ld using a pair of lenses are designed , and the characteristics such as output power and power stabilization of both solid - state lasers are investigated . thirdly , when an empty liquid crystal cell is inserted in the cavity of the nd : yag laser pumped by high power ld , the laser can operates in single axial mode . finally , according to the relationship between the laser output power and the longnitudinal a ld - end - pumped nd : yag laser sensor for displacement measurement has been investigated theoretically and demonstrated experimently , the results indicate that when the mean radius of pumping inside the laser cavity is far less than that of the oscilating laser mode , the exponential of the output power is a gauss function of the longitudinal positon of focused spot of ld pumping beam , both the measurement range and the sensitivity are dependent on the incident pumping power , as the incident pumping power is increased , the measurement range is enlarged and the sensitivity is improve d 本文首先介绍了ld泵浦nd ： yag激光器的发展状况、主要特性及其应用，从四能级速率方程出发，推导了ld泵浦nd ： yag激光器的阈值、输出功率和斜效率的表达式，并简述了激光器的工作原理、结构型式和倍频方法；其次，以空间相关的速率方程为基础，提出了ld端面泵浦nd ： yag激光器的设计方法，给出了一定泵浦耦合方式下，振荡光模尺寸、最佳输出耦合率、泵浦光模尺寸、泵浦光焦斑位置等参数的选取依据，以此为依据，设计了自聚焦透镜耦合小功率ld泵浦nd ： yag激光器和透镜组耦合高功率ld泵浦nd ： yag激光器，对激光器的输出功率和功率稳定性等特性进行了实验研究；再次，在带尾纤输出的高功率ld泵浦nd ： yag激光腔内插入一只空液晶盒，观察到了激光器以单纵模运转；最后，根据泵浦光焦斑端面位置对激光输出功率的影响规律，提出了ld端面泵浦nd ： yag激光位移传感新方法，并进行了理论和实验研究，研究结果表明：当激光晶体内泵浦光平均光斑半径远小于振西安理工大学硕士学位论文荡光束腰半径时，激光输出功率的自然指数与泵浦光焦斑的纵向位置成高斯变化规律，测量范围和灵敏度依赖于泵浦功率，随着泵浦功率的增加，测量范围扩大，灵敏度提高，当端面泵浦功率为7 . 24w (最大输出功率为1 . 926w )时，激光位移传感器的测量范围和灵敏度分别是13 . 045mm和0 . 148mw / pm 。
With the theoretical and experimental methods , the characters of cr4 + : yag are studied from cr4 + : yag as passive q - switching in nd : yag laser , intracavity frequency - doubling of q - switching laser and dual - wavelength laser , which is based on cr4 + : yag ' s operations of saturable absorption and laser gaining medium . chapter 1 : introducing the cr4 + : yag ' s optical function , the general research situation and the main idea of this thesis 本论文基于cr ~ ( 4 + ) yag晶体既可以作为nd yag激光器的被动调q开关、又可以作为激光增益介质的特点，采用理论和实验相结合的研究方法，详细而具体的研究了cr ~ ( 4 + ) yag晶体被动调q 、调q倍频和双波长激光输出的特性。
With the cavity of output from zero - order diffractive beam , tunable range of about 70nm from 543 - 610nm had been achieved , and the highest slope efficiency of 17 % was obtained at 583nm wavelength . while using the cavity of output from a coupling mirror , tunable range of over 30nm from 553 - 585nm was obtained , and the 在腔镜耦合输出的可调谐激光器实验中，输出调谐范围超过30nm ，此结果与报道的p567固态染料调谐范围相近；在光栅零级输出实验中，激光输出调谐范围近70nm ，此结果在已知报道的p567固态染料激光调谐范围中是最宽的。
We calculate the stress fracture limit , critical index limit and melting limit in a high power double clad fiber laser . the results show that the average output power decreases when the temperature is too high . to maintain the pumping efficiency and the output power , some cooling methods should be used when the output power reaches a certain level 给出了热效应对双包层光纤激光器影响的裂解极限、临界折射率极限和熔化极限与光纤结构参数和泵浦功率的表达式,理论分析和数值模拟结果表明对于高功率的双包层光纤激光器温度很高时激光增益下降,在一定的功率水平上需要进行外界的冷却,以保证泵浦激光的效率和高功率的激光输出。
Compared with the traditional lamp - pumped solid - state lasers , the diode - pumped solid - state lasers ( dpssls ) have many advantages such as high efficiency , long lifetime , all - solid - state , small size and little heat effect , etc . of many kinds of dpssls , laser diode ( ld ) end - pumped nd : yag laser plays an important role and has been found wide applicatins in industry , mainly because of its good mechanical and optical properties of nd : yag crystal and good mode matching to output a fundamental transverse mode 与传统的灯泵浦相比，激光二极管泵浦固体激光器( dpssls )具有高效、长寿命、全固化、热效应和体积小等优点。在众多的dpssls中，激光二极管( ld )端面泵浦nd ： yag激光器在工业中起着重要的作用并得到了广泛的运用，这主要归因于nd ： yag晶体具有良好的机械和光学特性，而且端面泵浦具有良好的模式匹配，能获得基横模激光输出。
A laser diode with 976nm center wavelength and 2 . 03w maximum cw output power is pumping unidirectionally through the couple - imaging system on a double - clad yb - doped silica fiber with a yb - concentration 0 . 65 mol % circular inner core , a d - shaped inner clad , and 15m length by f - b cavity . the center wavelength of the fiber laser is 1130nm , and the maximum cw output power is 130 . 7mw . an optical - to - optical conversion efficiency of 42 % and a slope efficiency of 63 . 4 % are obtained 用中心波长976nm 、最大连续输出功率为2 . 03w的ld泵浦源，通过成像耦合系统，单端直腔式泵浦纤芯掺杂浓度为0 . 65mol % 、内包层截面形状为d形、长度为15米的双包层掺镱石英光纤，实现了中心波长1130nm 、最大功率为130 . 7mw的连续激光输出，光纤激光器的光光效率为42 . 0 % ，斜效率达到63 . 4 % 。
Tunable external cavity semiconductor lasers ( ecld ) are useful for generating frequency tunable laser radiation of narrow spectral width , and providing important system for studying interactions between light and matters the dynamic and static characteristics of the bistable output of an ecld have been studied in this work under the condition of strong feedback 外腔半导体激光器( ecld )可以产生可调谐的窄线宽激光输出，它也为研究光与物质的相互作用提供了一个重要的场所。本文研究了强反馈条件下外腔半导体激光器调谐输出的双稳动静态特性。
The technical breakthroughs in growth of nd : cngg had been made . in particular , continuous laser operation was achieved from nd : cngg pumped by ld . when the crystal wafer was end - pumped by one bar of ld with 807nm wavelength , the cw laser output power of 123 . 1 mw was obtained with slope efficiency of 22 . 3 % 本论文用自动化熔体提拉技术成功生长出< 111 >方向的直径25mm以上,长度80mm以上的平界面无核心nd : cngg单晶,确定了晶体结构和物相,测量了晶体的光谱性能,晶体消光比达到34db ,晶体生长技术有新的突破,实现了连续激光运转,用单支807nm半导体激光二极管端面泵浦该晶体片子,在国内首次获得123 . 1mw的1 . 062 m连续激光输出,斜效率达22 . 3 % 。
