利用复合Nd∶YAG实现600mW高效紧凑型蓝光激光器

报道了采用复合Nd∶YAG晶体 ,LBO腔内倍频 ,简单的平凹谐振腔结构实现大功率LDA泵浦条件下高效率蓝光激光器 利用大功率泵浦情况下晶体的热透镜效应实现最优模式匹配 ,在可吸收泵浦功率为 15 .0 9W时 ,激光器的 4 73nm蓝光功率输出达 6 0 0mW ,光 光转化效率达3.98%     

LD泵浦Nd∶YAG/LBO蓝光激光器的低噪声运转

观察了LD泵浦Nd∶YAG晶体,I类临界相位匹配LBO晶体腔内倍频的473 nm蓝光激光器的噪声特性,指出蓝光噪声主要来自于不同纵模的相互耦合,并用双折射滤光片技术实现了全固态蓝光激光器的低噪声稳定运转.在1.3W的泵浦功率下,获得了58mW的蓝光低噪声稳定输出.     

LD泵浦Nd:YAG/LBO蓝光激光器的低噪声运转

观察了LD泵浦Nd:YAG晶体,I类临界相位匹配LBO晶体腔内倍频的473nm蓝光激光器的噪声特性,指出蓝光噪声主要来自于不同纵模的相互耦合,并用双折射滤光片技术实现了全固态蓝光激光器的低噪声稳定运转在1.3W的泵浦功率下,获得了58mW的蓝光低噪声稳定输出.     

473 nm和946 nm双波长输出的全固态Nd:YAG激光器

设计并实现了473 nm和946 nm双波长输出的全固态Nd:YAG激光器.利用激光二极管端面泵浦Nd:YAG晶体,在三镜折叠谐振腔中插入Brewster窗片作为起偏器,通过周期极化晶体PPKTP内腔倍频获得473 nm蓝光输出.同时利用Nd:YAG激光晶体的热退偏效应,把Brewster窗片作为基频光输出耦合镜,实现946 nm激光输出.通过调谐PPKTP的温度,优化了倍频光和基频光的输出功率.泵浦功率25W时,实验获得了1.8W的473 nm倍频蓝光和0.8W的946 nm基频激光输出.     

LD双端端面泵浦的高功率连续单频Nd:YVO4激光器

通过研究Nd:YVO4晶体在不同Nd3+掺杂浓度下对泵浦激光的吸收特性,以及激光晶体因吸收泵浦光而产生的热效应,在理论上分析了大功率泵浦情况下全固体化单频Nd:YVO4激光器中激光晶体Nd3+掺杂浓度对激光输出特性的影响,得出了激光器的输出功率、泵浦阈值以及斜效率与晶体掺杂浓度的对应关系.在实验上对晶体掺杂浓度分别为0.2 at%、0.3 at%和0.5 at%的大功率全固体化单频Nd:YVO4激光器的输出功率进行了比较,实验结果和理论预测基本吻合.当Nd:YVO4晶体的Nd3+掺杂浓度为0.3 at%,在44.3 W泵浦光功率下,我们在实验室得到18 W单频连续1.064 μm激光输出,激光器的斜效率为49.4%.     

高稳定LD端面泵浦腔内倍频Nd∶YVO4/LBO连续红光激光器

设计出一种能够较好地补偿激光晶体热效应的激光谐振腔,实现了高稳定LD单端泵浦LBO腔内倍频Nd∶YVO4连续红光激光器.当晶体吸收的泵浦功率为24.56 W时,671 nm激光功率达到1.203 W,光-光转换效率4.9%,激光模式为TEM00模.在输出功率为1.08 W时,激光器1 h功率不稳定度为0.52%.     

输出功率5.2 W的全固态连续单横模671 nm红光激光器

设计了全固态连续单横模671 nm红光激光器.利用880 nm LD双端端面泵浦Nd:YVO4复合晶体,实现了均匀泵浦并改善了激光晶体热效应;考虑到影响倍频转化效率的各种因素,优化设计了Z字形四镜激光谐振腔,采用I类临界相位匹配晶体LBO作为腔内倍频晶体;当泵浦功率为42.5W时,获得了5.2W的连续单横模671 nm红光输出,光-光转化效率达到12.2％,激光器长期功率稳定性优于±2.5％(1 h).     

LD泵浦Nd∶LuVO_4/Cr~(4 )∶YAG被动调Q激光器

采用大功率半导体激光器端面泵浦Nd∶LuVO4晶体,利用Cr4 ∶YAG晶体作为可饱和吸收元件,实现了1.06μm激光的被动调Q运转.在泵浦功率为19.1W时,获得最高平均输出功率为4.58W,脉冲宽度为84ns,单脉冲能量为36.6μJ以及峰值功率为436.2W的激光脉冲.     

高稳定LD泵浦腔内倍频Nd∶YVO4/KTP连续绿光激光器

设计出一种能够较好地补偿激光晶体热效应的激光谐振腔，实现了高稳定LD单端泵浦KTP腔内倍频Nd∶YVO₄连续绿光激光器.当晶体吸收的泵浦功率为24.56 W时，532 nm激光功率达到5.3 W，光-光转换效率达到21.6％，激光模式为TEM00模.在输出功率5W左右时，激光器1 h功率不稳定度优于0.6％     

LD泵浦Nd∶LuVO4/Cr4+∶YAG被动调Q激光器

采用大功率半导体激光器端面泵浦Nd∶LuVO4晶体，利用Cr4+∶YAG晶体作为可饱和吸收元件，实现了1.06 μm激光的被动调Q运转.在泵浦功率为19.1 W时，获得最高平均输出功率为4.58 W，脉冲宽度为84 ns，单脉冲能量为36.6 μJ以及峰值功率为436.2 W的激光脉冲.     

高功率超宽带脉冲辐射实验装置研制

 研制了高功率超宽带脉冲辐射实验装置。该装置主要由脉冲充电电源、超宽带脉冲产生装置、超宽带脉冲发射天线三部分组成。达到的主要指标为：脉冲电源输出电压600 kV、重复频率100 Hz；脉冲压缩输出峰值功率约10 GW、脉宽1.2 ns；在辐射天线轴上220 m处，辐射峰值电场16.1 kV/m、等效辐射功率0.42×10¹² W；辐射场E面方向图半功率宽度为8°，H面方向图半功率宽度为9°。     

High-repetition-rate mid-infrared optical parametric oscillator based on PPMgOLN

A compact source of high-repetition-rate, high-efficiency, mid-infrared optical parametric oscillator (OPO) based on periodically poled MgO-doped lithium niobate (PPMgOLN) was reported. To ensure high conversion efficiency at high repetition rate, a high beam quality and high peak power Q-switched pump source was developed specially. The performances at different repetition rates were compared and average output power of 8.7 W at 3.8 ??m was obtained when the pump power was 48 W at the repetition rate of 120 kHz with an optimal plane-concave resonator configuration. The conversion efficiency from the 1.06 ??m laser to the 3.8 ??m laser was 18.1%.     

Single-frequency, single-mode, plane-polarized ytterbium-doped fiber master oscillator power amplifier source with 264 W of output power

We present a single-frequency, single-mode, plane-polarized ytterbium-doped all-fiber master oscillator power amplifier source at 1060 nm generating 264 W of continuous-wave output power. The final-stage amplifier operated with a high gain of 19 dB and a high conversion efficiency of 68%. There was no evidence of rollover from stimulated Brillouin scattering even at the highest output power, and the maximum output was limited only by the available pump power.     

High-power and high-frequency operation of InGaAsP/InP lasers at 1.3 μm

A simultaneous operation of a semiconductor laser at high power and high speed was demonstrated in a buried crescent laser on p-InP substrate. In a cavity length of 300 μm, a maximum continuous wave (CW) power of 130 mW at room temperature was obtained in a junction-up mounting configuration. A 3dB bandwidth in excess of 12 GHz at an output power of 52 mW was observed.     

一种高效的2.45 GHz二极管阵列微波整流电路

 采用4只HSMS 282肖特基二极管阵列,对大功率微波整流电路进行了研究。构造了基于微带线结构的2.45 GHz高效微波整流电路,将微波整流单元电路的输入功率提升到33 dBm。仿真和实验结果表明,在一定微波输入功率的条件下,整流电路在负载较大范围内变化时保持了高整流效率。通过在不同微波输入功率和负载下进行测量,发现当输入微波功率为27.0~31.7 dBm之间变化时,最高整流效率均达到了60%以上,当微波输入功率为30 dBm时,微波整流电路效率达到了63.3%。     

High quality factor superconducting coplanar waveguide fabricated with TiN

We fabricated TiN coplanar waveguides using standard lithography techniques followed by ICP etch. In order to achieve high quality factor, we investigated the film growth by choosing different deposition conditions for various substrates. Quality factors of waveguide resonators were measured at 20 mK in both high and low microwave power limits. An inner quality factor of several million was achieved at high power limit for a predominantly(200)-oriented TiN film which was grown on HF cleaned silicon wafer. A quality factor of larger than one million was achieved at high power limit for TiN film grown on sapphire.     

Characterization of tungsten-titanium oxide electrode for electrochromic applications

Titanium oxide films are of critical importance for the electrochromic device technology. The substrate, a conductive glass being coated with indium tin oxide (ITO) thin films, was deposited tungsten and titanium oxide by pulsed co-sputtering deposition system. The film thickness increased with the ion beam power. However, the slope of the curve of thickness against power at an ion beam power of less than 300 W was greater than that at a power of 400 or 500 W. A high ion beam power resulted produced a crystalline structure, as revealed by X-ray diffraction (XRD). Moreover, increasing the ion beam power resulted in the high Li-ions transport. The electrochromic behavior was optimal at an ion beam power of 200 W.     

High repetition rate,high peak power acousto-optical Q-switched 946 nm Nd:YAG laser

A diode-end-pumped high repetition rate, high peak power acousto-optical (AO) Q-switched 946 nm Nd:YAG laser was demonstrated in this paper. In our experiments, a 20 mm miniature acousto-optical Q-switch was employed in a 45 mm linear laser cavity for generating the short laser pulse. At a repetition rate of 10 kHz, a maximum average output power of 2.9 W was achieved with a pulse width of 24.4 ns, giving a peak power of 11.9 kW. To the best of our knowledge, this is the highest peak power 946 nm Nd:YAG laser at high repetition rate operation. Moreover, pulse train with good stability was also obtained at the repetition rate of 50 kHz. At an incident pump power of 22.3 W, up to an average output power of 3.5 W pulsed 946 nm laser was generated at 50 kHz with a pulse width of 69 ns, corresponding to an optical conversion efficiency of 15.7% and an average slope efficiency of 24.1%, respectively.     

X波段极化可重构高功率微波辐射器仿真设计

为了提高高频段高功率微波反射面天线的馈电效率,同时使波束波导馈线更加紧凑,提出一种新型的X波段极化可重构高功率微波辐射器结构。通过波纹喇叭辐射器产生准高斯的HE11模辐射,采用双相位修正镜组成的波束变换系统实现将准高斯波束转换为电场分布更为均匀的平顶波束或其余期望分布的波束,平顶分布的输出波束可使得馈源在相同介质窗尺寸下获得更高的功率容量,同时实现了波束传播方向的90°转弯;此外采用双圆极化栅网的级联组合,实现了对输出波束极化特性的调变。通过全电磁波仿真分析验证了该辐射器的设计思路。     

HL-2A装置低混杂波传输系统特性测量分析

2006年和2008年分别对HL-2A装置的低混杂波传输系统传输特性进行了冷测量和热测量工作。测量结果表明,冷测量传输率达到了94.05%,四个分路的最大相差为11.09°,功率分配也比较均匀;热测量传输率为76%~95%,但功率分配均匀度较差。另外,热测量功率超过230kW时,传输率有明显下降。