东北大学秦皇岛分校毕业设计（论文） 第 32 页
光, 2007, 34(9):1171 -1173.
[16] 吴玉松,潘裕柏,李江,等.Yb∶YAG透明陶瓷的制备和激光输出[J] .无机材料学报, 2007, 22 (6 ):1086 -1088.
[17] 单欣岩,魏晓羽,吴念乐,等.二极管泵浦Yb∶YAG ThinDisk激光器光束质量及V形腔腔内倍频的研究[J] .量子电子报,2004, 21(5):587 -591.
[18] 李磊,杨苏辉,孙文峰,等.激光二极管抽运的高光束质量的Yb∶YAG薄片激光器[J].中国激光, 2004, 31(11)1285-1288.
[19] 宋秋鸣,陈长水,殷绍唐.激光二极管泵浦Yb∶YAG激光器[J] .量子电子学报,2005, 22(4):525 -527.
[20] 王建军,姜东升,赵鸿.二极管侧面泵浦固体激光器TEM00模输出研究[J] .激光与红外, 2000 , 30(5):286~288
[21] 候霞,陆雨田,胡企铨.折返式激光二极管侧Nd3+:YAG 激光器[J].光学学报,2004 , 24(10):1349～1352
[22] 王建军,姜东升,赵鸿.二极管侧面泵浦固体激光器TEM00模输出研究[J] .激光与红外, 2000 , 30(5):286~288
[23] 王族,张洪明,张无鉴等.基于饱和吸收镜的被动锁模光纤激光器[J].中国激光,2007, 34 (2) :163-165
[24] 王石语,过振,傅君眉,等.抽运光分布对二极管抽运激光器振荡光光束质量的影响[J].物理学报,2004,53(9):2995-3003.
[25] 王晓丹,赵志伟,徐晓东等.Yb掺杂原子数分数为0.5%的Yb∶Y3Al5O12晶体的光谱分析[ J] .中国激光, 2006 , 31(11):692~696
[26] 张行愚,赵圣之,王青圃等.Cr4+:YAG调Q特性的理论和实验研究[J].光学学报,1998, 18(9):1180~1185
[27] 巩马理,翟刚,时顺森等.Cr4+:YAG可饱和吸收特性测量[J].光学学报,1998,18 18(1):124~127
[28] 张行愚,王青圃,赵圣之.固体脉冲激光器的反转因子[J].光学学报,1994, 14(7):687~691
[29] 欧攀，戴一堂,王爱民．高等光学仿真[M]北京：北京航空航天大学出版社，1982
东北大学秦皇岛分校毕业设计（论文） 第 33 页
附 录
附录A
3?
LD pumped Nd:YAG microchip lasers
Abstract:A new experimental result obtained for the first time about LD pumped Nd:YAG microchip lasers in China is presented. The output power reached 62. 5mW，when the input power was 340mW. The optical efficiency was 18%.The experimental setup and the unique characteristics of the lasers are given and discussed.
It is well-known that using laser diodcs(LD) instead of flash lamp as pumping source is a revolutionary progress for solid state lasers. Compared with flash一lamp pumped solid state lasers，LD pumped solid state lasers (DPL)have many advantages，such as，compactness，high efficiency，durableness，etc. Compared with laser diodes，DPL also have many advantages，such as，narrow linewidth，good beam quality，different wavelengths，etc. For these reasons，DPL have attracted scientists' s attention for many years.
Two years ago，we developed a LD pumped miniature Nd:YAG rod laser，which can be operated continuously with the fundamental transverse mode. The output power was very low，since a single stripe GaAIAs laser with the output power of 20mW was used. There were 3-5 longitudinal modes in its optical spectrum. It was not possible to obtain single longitudinal mode from the laser，because its cavity length was too long(5mm).
In order to obtain a single longitudinal mode from DPL，the simplest way is to use a short cavity，in which the interval between adjacent longitudinal modes must be the gain bandwidth. Recently，we are carrying out a research work on single larger than longitudinal mode LD pumped microchip lasers，and obtained a very good result from a LD pumped Nd:YAG microchip laser. The output power reached 62.5mW when the pumping power from a laser diode array was microchip lasers other properties array was 340mW.The optical efficiency was 18%.This result for LD pumped obtained for the first time in China.The
3?3?3?
东北大学秦皇岛分校毕业设计（论文） 第 34 页
experimental setup and some about the laser are given as follows.
A GaAIAs laser array with the threshold current of 353mA and the maximum output power of 500mW at 805-810nm was used. The size of the Nd:YAG microchip was 6×6mm2 and its thickness was 700μm. The input side of the microchip was coated as high transmission for the wavelength of 810nm and high reflection for the wavelength of 1.06?m. Two lens systems were used in the experiment.
3?FF12?2FF12?12These
lens systems could be
simply obtained by exchanging the positions of lens 1 and lens 2.The focal lengths of lens 1 and lens 2 were 115mm and 60mm，respectively. HereF1meant the focal length of the lens whichwas near to the laser diode，F2was the focal length of the lens which was near to the
Nd:YAG microchip. In the case of F1F2?2，the pumping light spot was smaller than that in the case of
3?F1F2?12 .The
output light beam was observed or measured by IR
converter,CCD camera,powermeter and monochromator，etc.
The property of the LD pumped Nd:YAG microchip laser in the pulse operation is shown in Fig 2. The above curves represent LD current waveforms. The below curves represent optical output waveforms. The situation below the threshold is in(a)，only spontaneous emission can be seen. (b) shows the situation at the threshold. The optical output pulse has been reduced for displaying stimulated radiation. (c)shows a situation at a high pumping level. A regular relaxation oscillation can be seen at the beginning of the output pulse. The enlarged relaxation oscillation is shown in(d).This one was not so good.Sometimes，we could obtain a very good relaxation oscillation picture with the amplitude decayed exponentially.
The output-input curves of the LD pumped Nd:YAG are shown in Fig.3. In this case，the threshold power was 60mW. The maximum output power was reached In 62.5mW，when the input power was 340mW. The optical efficiency was 18%.In this case threshold power was only 20mW. The maximum output power was 39mW，when the input power was still 340mW. The efficiency was 11%.
The transverse modes of the LD pumped Nd:YAG microchip laser are given in Fig4 .We obtained TEM00,TEM20 ect.by shifting pumping position.The fundamental transverse mode and tis intensity distribution measured by a CCD system are given in
3?3?3?
东北大学秦皇岛分校毕业设计（论文） 第 35 页
Fig5.After calculation,we found that the divergent angle of the output beam at 1.06 was 2 mrad.
The transverse modes of the LD pumped Nd:YAG microchip laser are given in Fig4 .We obtained TEM. By shifting pumping position. The fundamental transverse mode and tis intensity distribution measured by a CCD system are given in Fig 5. After calculation,we found that the divergent angle of the output beam at 1.06 was 2 mrad.
The interesting thing was that after the LD pumped Nd:YAG microchip laser was realigned, we could still obtain the 1.06um laser beam,when the microchip was rotated vs.optical axis by a angle. In the case of F1/f2=2，the rotating angle was士200. In the case of=1/2，the rotating angle was士150. It is impossible to observe the phenomenon in LD pumped Nd:YAG rod lasers ,where an alignment is very critical.
A very good result about LD pumped Nd:YAG lasers was obtained for the first time in China. The output power of the LD pumped Nd:YAG microchip laser reached 62. 5mW and the efficiency was 18%. LD pumped microchip solid state lasers are beneficial to the operation of a single longitudinal mode. But，at present，we do not test its optical spectrum，as the experimental setup was too big to move for the testing . LD pumped microchip solid state lasers can become a very miniature laser，because a laser diode and a microchip cavity are all very small. But now，our experimental setup was still large，since a large lens system was used. We are making efforts to reduce the size of the lens system.Our purpose is to develop a lensless LD pumped microchip laser. Of course，may be there are a lot of difficulty to do this. But it will be very useful.
For a plane-plane cavity，it is important to understand the guiding mechanism of transverse modes. We are investigating the property of the transverse modes of LD pumped Nd:YAG microchip lasers. At present，we can not say what is the condition for the fundamental transverse mode operation，why various transverse modes can be obtained by shifting the position of the pumping light beam，why the fundamental transverse mode can be obtained by using a laser diode array as a pumping source，and so on.
LD pumped solid state microchip lasers are beneficial to mass-production. They have characteristics of solid state lasers，but in laser diode size. They will have many applications in various areas.
3?3?3?3?3?3?
东北大学秦皇岛分校毕业设计（论文） 第 36 页
中文译文
激光二极管抽运的被动调Q微晶片激光器
摘要：首次对LD抽运的Nd获得的新的实验结果Nd:YAG激光器芯片在中国出现。输出功率达到5mW，当输入功率为340mW。光效率为18％。实验设置和激光器的独特的特点，给出和讨论。
众所周知，使用激光二极管来代替闪光灯作为抽运源(LD)对于固态激光器来说是革命性的进步。与闪光灯抽运的固体激光器相比，LD抽运的固体激光器(DPL)具有许多优点，如体积小，效率高，经久耐用等。与激光二极管相比，DPL也具有许多优点，如，窄线宽，光束质量好，具有不同波长的光，等等。由于这些原因，DPL已经令科学家们关注了很多年。
两年前，我们开发了LD抽运的微型的Nd3?:YAG激光棒，它可以不断地在基本横向模式下运行。输出功率是非常低的，因为使用的是单个条纹GaAIAs激光与20mW的输出功率。有在其光谱3-5纵模。这是不可能获得来自激光单纵模，因为其腔长度太长(5mm)。
为了从DPL中获得单纵模，最简单的方法是使用一个短腔，其中相邻的纵向模式之间的间隔必须是增益带宽。最近，我们正在开展研究工作，关于比纵模单LD抽运放大微晶片激光器，在LD抽运Nd3?:YAG激光芯片取得了很好的效果。输出功率达到62.5mW时来自激光二极管阵列的抽运功率为微片激光器等性能阵列为340mW。在中国首次获得的LD抽运18％的出光效率。实验装置和一些有关激光的数据如下。
一种GaAIAs激光器阵列与353毫安的阈值电流和500mW的在805-810nm的最大输出功率使用。Nd3?:YAG微晶片的大小为6*6平方毫米，其厚度为700微米。微芯片的输入侧涂布高传输为810nm和高反射的波长为1.06μm的波长。在实验中使用两个透镜系统。这些透镜系统可以通过交换透镜1和透镜1的透镜2，焦距和透镜的位置分别为2分别115毫米60毫米，可以简单地获得。F1为接近激光二极管透镜的焦距，F2是为接近Nd3?:YAG透镜的焦距。在的情况下，抽运光点在F1F2?2的条件下时明显低于在F1F2?12的条件下。输出光束可以通过红外转换器，CCD摄像头，功率计和单色
3?