共查询到19条相似文献,搜索用时 343 毫秒
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采用光栅角色散的宽带二倍频及聚焦特性分析 总被引:3,自引:3,他引:0
针对带宽为20 nm左右、中心波长为1 053 nm的线性啁啾宽带激光,分析了采用光栅角色散方式宽带二倍频的原理,讨论了光栅角色散性能及光栅加工误差引入的基频光位相扰动对二倍频光转换效率及聚焦特性的影响.研究结果表明:采用光栅角色散方式的宽带二倍频光的转换效率、脉冲宽度和带宽均明显增大;在0~22 nm基频光带宽范围内,二倍频光均可保持80%左右的转换效率;对于入射基频光带宽为22 nm的情况,光栅角色散率在30~80 μrad/nm范围内变化时,宽带二倍频转换效率均可保持在70%以上;基频光有位相扰动时,二倍频光带宽对二倍频聚焦光斑的主瓣影响不大,但对旁瓣有一定的匀滑作用,采用光栅角色散方式宽带二倍频的聚焦光斑旁瓣的匀滑效果更为明显. 相似文献
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全固态腔内SHG/SFG多波长黄光激光器 总被引:1,自引:0,他引:1
报道了一种利用大功率激光二极管端面抽运Nd…YAG激光晶体产生基频光,并通过非线性晶体的腔内倍频(SHG)与和频(SFG),实现多个二次谐波同时连续输出的多波长黄光激光器。将Nd…YAG晶体的1112.1、1115.9、1122.7nm谱线作为基频光,利用LBO和BIBO进行非线性光学频率变换,同时获得了三个倍频光及三个和频光激光输出。从理论上对基频光同时受激跃迁和非线性频率变换相位匹配进行了分析。实验结果与理论分析表明,当基频光的性能相对接近时,合理地选择性能较好的非线性晶体对基频光同时进行倍频和和频是获得全固态多波长激光器的一种实用方法,合理地设计激光器谐振腔能够提高激光器的稳定性。 相似文献
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介绍了一种基于新型非线性晶体Ba1-xB2-y-zO4SixAlyGaz 的可调谐深紫外飞秒激光光源. 从理论上分析了基频光和倍频光在通过非线性晶体时所造成的空间走离和群速度失配, 为了补偿空间走离以及波长调谐过程中晶体折射造成的光束偏离现象, 将两块相同的倍频晶体成镜像放置来产生二次谐波. 并调节延迟线的长度来补偿基频光和倍频光之间的群速度失配, 从而提高和频转换效率. 然后通过和频方式进行三倍频和四倍频来突破晶体相位匹配条件的限制, 产生了波长低于200 nm的深紫外飞秒激光. 利用钛宝石激光器提供基频光光源, 最终在250–300 nm, 192.5–210 nm 范围内获得了高重频、可调谐超短脉冲紫外和深紫外激光. 并在基频光波长为800 nm时, 得到的二倍频、三倍频和四倍频的功率分别为1.28 W, 194 mW和5.8 mW, 相对于前一级的转换效率依次为46.14%, 15.16%和3%. 采用互相关法测量得到266.7 nm紫外激光的脉冲宽度约为640.4 fs. 相似文献
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《光学学报》2010,(4)
根据KBBF(KBe_2O_3F_2)晶体的色散方程、非共线相位匹配时各个光束应该满足的能量和动量守恒条件,用牛顿-拉夫逊迭代法求解非线性方程组,以YAG激光器1064 nm波长入射为例,数值计算了KBBF晶体的Ⅰ类非共线倍频相位匹配角、有效非线性系数和允许角。结果以关系曲线形式给出。第一束基频波角度在20°~85°的范围内,都可以实现非共线相位匹配,相应的第二基频波和倍频波的匹配角度在29.1°~52.7°,24.6°~68.8°范围内;随着第一束基频波角度的增大,第二基频波和倍频波的相位匹配角以及倍频光相位匹配允许角也相应增大,而有效非线性系数随之减小;当第一束基频波的角度在26.1°~26.8°的范围内时它们的取值都出现了振荡现象。 相似文献
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针对时间位相调制的宽带激光,采用分步离散傅里叶变换及四阶龙格-库塔算法进行数值模拟计算。讨论了采用KDP晶体级联方式时,入射基频光的光强、带宽以及晶体厚度对三倍频转换效率的影响。对采用一块РⅠ类二倍频晶体、一块Ⅱ类和一块Ⅰ类双混频晶体的级联宽带三倍频方式进行了晶体参数的优化。研究结果表明,使用两块级联的KDP晶体作为混频晶体,不仅能有效地提高带宽较宽条件下三倍频光的转换效率,还可以显著增大宽带三倍频的动态范围。经优化后,带宽1.11 nm时入射基频光强在3~8 GW/cm2范围内的三倍频转换效率可保持在60%~70%,比采用单倍频单混频方案时增大了30%~40%。 相似文献
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阐述了一种基于单块周期极化铌酸锂晶体级联三倍频实现440 nm蓝光输出的实验方案。根据周期极化铌酸锂晶体的Sellmeier方程以及倍频与和频的相位匹配条件,在一块周期极化铌酸锂晶体上设计了两段不同的极化周期,使其在同一工作温度下能分别实现倍频与和频,在先后经过倍频与和频后,实现级联三倍频输出。实验采用Nd: YAG产生的1319 nm光作为基频光,重频400 Hz,脉宽110 ns,横向和纵向光束质量因子分别为1.81和2.65。耦合进周期极化铌酸锂晶体后,出射光中检测到660 nm的红光和440 nm的蓝光。通过调整工作温度和入射基频光功率,得到2.4 mW的最大蓝光输出,此时工作温度55.5 ℃,基频光功率530 mW。实验结果验证了单块晶体实现级联三倍频440 nm蓝光输出的可行性。 相似文献
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针对时间位相调制的宽带激光,采用分步离散傅里叶变换及四阶龙格-库塔算法进行数值模拟计算。讨论了采用KDP晶体级联方式时,入射基频光的光强、带宽以及晶体厚度对三倍频转换效率的影响。对采用一块РⅠ类二倍频晶体、一块Ⅱ类和一块Ⅰ类双混频晶体的级联宽带三倍频方式进行了晶体参数的优化。研究结果表明,使用两块级联的KDP晶体作为混频晶体,不仅能有效地提高带宽较宽条件下三倍频光的转换效率,还可以显著增大宽带三倍频的动态范围。经优化后,带宽1.11 nm时入射基频光强在3~8 GW/cm2范围内的三倍频转换效率可保持在60%~70%,比采用单倍频单混频方案时增大了30%~40%。 相似文献
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被动调Q产生1064 nm脉冲激光在腔外聚焦后入射到KTP中,产生532 nm的倍频光,再通过LBO和频产生355 nm激光。当抽运功率为3.4 W时,基频光调Q输出平均功率为350 mW,峰值功率达3.5 kW。腔外二倍频532 nm绿光输出平均功率为110 mW,用Ⅰ类相位匹配LBO晶体和频获得36 mW的355 nm的紫外激光输出,三倍频效率(1064~355 nm)达到10.2%。由于Cr∶YAG晶体达到饱和吸收后,会呈现出各向异性的特征,对基频光的偏振状态有很大影响。实验中必须合理放置复合晶体,使基频光的偏振状态为近似线偏振以提高转换效率。 相似文献
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A new scheme with non-collinear sum frequency generation (SFG) process of broadband third harmonic generation (THG) with two KDP crystals (one doubler and one mixer) using angular dispersion was proposed. The principle of broadband harmonic generation with non-collinear angular dispersion was presented. The comparison between the schemes of non-collinear and collinear SFG process was performed. The effects of the angular dispersion on the conversion efficiency, the pulse shape and the spectrum of the third harmonic field were discussed. The results show that, if proper angular dispersion is added to the fundamental and the second harmonic field outside the mixing KDP crystal, respectively, the broadband third harmonic conversion efficiency can be improved significantly. However, the difficulty of this scheme arises due to the requirement of two gratings with different angular dispersion outside the mixer. With the new scheme, it can be simpler that only one grating is needed to realize the broadband phase matching in the non-collinear SFG process. Although the fundamental and the second harmonic field inside the mixing crystal are non-collinear except the center wavelength, a blazing grating with proper angular dispersion for the fundamental field (twice as that for second harmonic field) can yield the well compensation for phase mismatching in the SFG process. Consequently, the conversion efficiency and the characteristics of the third harmonic field for the broadband third harmonic generation can be improved significantly. 相似文献
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The resonant third-harmonic generation of a self-focusing laser in plasma with a density transition was investigated. Because of self-focusing of the fundamental laser pulse, a transverse intensity gradient was created, which generated a plasma wave at the fundamental wave frequency. Phase matching was satisfied by using a Wiggler magnetic field, which provided additional angular momentum to the third-harmonic photon to make the process resonant. An enhancement was observed in the resonant third-harmonic generation of an intense short-pulse laser in plasma embedded with a magnetic Wiggler with a density transition. A plasma density ramp played an important role in the self-focusing, enhancing the third-harmonic generation in plasma. We also examined the effect of the Wiggler magnetic field on the pulse slippage of the third-harmonic pulse in plasma. The pulse slippage was due to the group-velocity mismatch between the fundamental and third-harmonic pulses. 相似文献
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Jing Li 《Optics Communications》2007,277(1):114-117
In the paper, a new way of intracavity frequency-tripled all-solid-state laser to generate continuous wave blue coherent radiation is firstly demonstrated. High-efficiency of continuous wave third harmonic generation using the approach of double-resonance at fundamental frequency and second harmonic is developed by insertion of one wedge prism for the phase control. The maximum output power at the wavelength of 447 nm, which was generated with two long LiB3O4 crystals by noncritical phase matching, is about 1.15 W with a beam quality factor of M2 of 1.05. From the experimental results, the generation of continuous wave blue light using this way with higher conversion efficiency can be achieved. 相似文献
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高效全固化紫外四倍频激光器的研究 总被引:7,自引:0,他引:7
用半导体激光器抽运的调Q YLF倍频激光器抽运掺钛蓝宝石激光器,用LBO晶体在腔内产生二次谐波,再聚焦到BBO晶体上产生四次谐波深紫外激光。为了提高谐波转换效率,在腔内分别插入了单片、组合双折射滤光片和聚焦透镜,在平均功率为3.6W,波长为527nm的抽运光下得到410mW,417nm的蓝光。用长焦距的透镜聚焦二次谐波,得到34mW,208nm的紫外脉冲激光。从实验上详细研究了基频光的线宽对二次谐波效率的影响,二次谐波的线宽对四次谐波效率的影响、基频光的波长对四次谐波产生效率的影响。全面地分析了单片和组合大拆射滤光片及抽运功率对钛蓝宝石激光器基频光的脉宽、线宽等参量的影响。 相似文献
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We present simultaneous phase matching of optical parametric oscillator (OPO) and difference frequency generation (DFG), using a noncollinear interaction in periodically poled crystal with single grating. Selecting proper grating period Λ and titled angle ξ between the grating vector G and the optical axis of crystal, the noncollinear scheme provides double phase matching solutions over continuous regions of the midwave infrared spectrum. At certain wavelength regions, for DFG process the group velocities between interaction pulses are matching and the phase matching bandwidth reaches maximum. Selecting the different grating period, the broadband midwave tuning and better gain spectrum can be obtained at different wavelength range. For the certain period grating the conversion efficiency is higher. Hence, using the double phase matching configuration, the broadband tunable midwave infrared wave can be produced in single grating. But the configurations have a relatively narrow angular bandwidth. 相似文献
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研制了一台LD侧面抽运Nd:YAP腔内三倍频447.1 nm脉冲蓝光激光器.采用列阵高频激光二极管侧面抽运Nd:YAP晶体,使用V型折叠腔,LN晶体电光调Q,输出高峰值功率的1 341.4 nm偏振基频光.选取KTP晶体Ⅱ类临界相位匹配倍频,获得670.7 nm红光.使用LBO晶体Ⅰ类临界相位匹配把670.7 nm的倍频光与1 341.4 nm的基频光进行和频,获得三倍频447.1 nm的蓝光输出.实验结果表明:优化后的V型折叠腔,可提高非线性转换效率,在平均抽运功率92.4 W时,获得了平均功率887 mW、峰值功率17.7 kW、脉宽50 ns的偏振蓝光输出,光-光转换效率为0.96%. 相似文献
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