LBO倍频1.8 W连续671 nm红光激光器

Nd：YVO4晶体中掺杂的Nd^3 除了1．064μm的受激辐射跃迁外，还可产生1．342μm波段的弱辐射，经腔内倍频，最终可输出671nm的红色激光。报道了一种光纤耦合半导体激光二极管(LD)阵列端面抽运Nd：YVO4晶体，腔内采用Ⅰ类临界相位匹配LBO(LiB3O5)晶体倍频，实现波长为671nm的全固态红光激光器瓦级输出的理论分析和实验结果。采用短三镜折叠腔结构，通过对激光晶体热透镜焦距的估算，用计算机优化设计选取了合适的谐振腔参数，在芯径为400μm的光纤耦合808nm半导体激光二极管阵列抽运下，当注入功率为8W时，获得了波长为671nm的红光基模稳定输出．最高输出功率达1．8W，光-光转换效率达22．5％。     

红磷烟幕对10.6 μm激光的消光系数测试研究

论述了红磷烟幕的成烟过程与遮蔽特性。在烟幕试验柜中测试了红磷烟幕对两种入射功率10．6μm激光的质量消光系数和红磷烟幕的粒度分布规律;根据米氏散射理论计算了单个红磷烟幕粒子对10．6μm激光的吸收效率因子、散射效率因子和消光效率因子。结果表明：红磷烟幕对入射功率分别为0．552、1．032W的10．6μm激光的平均质量消光系数分别为0．6027、0．5739m^2／g。成烟5min时红磷烟幕粒子的平均直径为2．47μm。研究表明,红磷烟幕对10．6μm激光的消光作用以吸收效应为主,其质量消光系数随浓度的增加而下降。同等条件下入射光的功率越大或空气的相对湿度越小．则红磷烟幕的消光系数就越小。     

LD泵浦的高效率YVO4/KTP红光激光器

报道了用国产半导体激光二极管泵浦Nd∶YVO4产生1.342μm输出,用Ⅱ类临界位相匹配KTP腔内倍频实现671nm的红激光输出。当泵浦注入功率为1.05W时, 倍频红激光基模输出达48mW,光光转换效率达到4.7%,经扩束准直后测得光束发散角小于0.5mrad,偏振比高于110∶1,24h连续工作功率稳定性优于±3%。     

Multiwavelength light emitters for scanning applications fabricatedby flipchip bonding

We present a multiwavelength light source which was fabricated using a self-aligned flipchip bonding technique. The device consists of an InGaN-GaN light-emitting diode emitting light at around 420 nm, on top of which we flipchip-bonded a monolithically integrated red/infrared dual-beam laser. The upper two lasers were built by selective removal of the red laser, and subsequent regrowth of an infrared laser structure. Since all processes, including the deposition of the PbSn solder bumps for bonding, were based on photolithographic precision, tight alignment tolerances of ±μm in the lateral direction could be fulfilled between the ridge waveguides of the three light emitters. For a high-speed color scanning system, this is an important design criterion because it will allow the use of a single scanning optics for the three laser beams     

8.1W全固态准连续红光Nd∶YAG激光器

报道了利用Ⅱ类临界相位匹配的KTP晶体(相位匹配角选为θ=599°,=0°)对Nd∶YAG在13μm附近的振荡进行腔内倍频,产生高功率准连续红光激光的实验结果。激光器使用了一个连续运转的高功率激光二极管(LD)侧面抽运组件(组件内由30个20W的二极管阵列呈三角形阵列分布抽运一根Nd∶YAG圆棒),使用声光调Q技术实现高重复频率输出,并选用了平凹直腔的腔体结构。对该激光器的基频(13μm波长)调Q和倍频红光的功率输出特性及光谱特性进行了研究。在LD抽运功率453W时产生了最大输出功率81W的准连续红光激光,测量了此时的M2值并给出了光强分布图。     

Intracavity 1.549-μm pumped 1.634-μm Er:YAG lasers at 300 K

A novel method of generating 1.634-μm laser action from Er:YAG crystals pumped intracavity by an Er:glass laser emitting at 1.549 μm is described. Operation of the Er:glass laser at 1.549 μm (red shifted from the standard 1.532 μm, but with comparable output) at 500 K was obtained using mirrors with tailored spectral reflectivities. Several Er:YAG crystals ranging in concentration from 0.3% to 2% and in length from 1 cm to 8 cm were lased in the intracavity pumping arrangement. All the Er:YAG crystals lased in the ⁴I_13/2 :Y1(6544 cm^-1)-⁴I_15/2:Z6(424 cm ^-1) 1.634-μm transition at 300 K     

激光二极管泵浦的1.34μm及其腔内倍频红光Nd: YVO_4激光器

报道了激光二极管泵浦的１．３４μｍＮｄＹＶＯ４激光器，利用ＫＴＰ晶体腔内倍频，实现了６７０ｎｍ红光输出。计算了ＫＴＰ在１．３４μｍ的倍频参数，分析并提出了提高腔内倍频效率的有效途径。     

Ⅰ类非临界相位匹配LBO腔外倍频660nm效率的研究

报道了利用LBO晶体对Nd:YAG纳秒激光器进行腔外倍频实验的研究结果,实验中LBO晶体采用Ⅰ类非临界相位匹配(NCPM),温度调谐。实验证明,采用LBO温度调谐方式具有倍频效率高、稳定性好、易于调节等优点,当匹配温度为8.4℃、基频光功率为1.3J时,获得了855mJ的660nm倍频光输出,最高转换效率达到66%,倍频光能量稳定度小于±3%。     

1.064μm激光在海水中传输特性的研究

为了实现激光雷达监测海洋赤潮的目的,采用红外激光能较好地反映藻类悬浮粒子密度等信息.分别就海水中水分子、浮游植物、黄色物质、悬浮颗粒与1.064μm激光的吸收和散射特性展开研究,最终构建了1.064μm激光在海水中的探测模型.通过对模型的仿真计算可知,红外激光雷达能有效地探测水下0.8m内的海水水域.结果表明,1.064μm激光水下探测深度可满足监测海洋表层藻类粒子密度的要求.     

Nd∶YAP/LBO腔内倍频高功率红光激光器

报道了使用三镜折叠腔Nd∶YAlO3 /LBO腔内倍频获得 6 70 7nm激光的研究。通过计算分析光学谐振腔参数 ,设计了较佳的谐振腔参数 ,在平均抽运功率为 1783W时获得了 3 2 6W的 6 70 7nm激光输出     

LD泵浦的1.34 μm Nd:YVO4晶体高效率激光器

报道了光纤耦合输出大功率LD模块泵浦的1.34 μm Nd:YVO4晶体高效率激光器,在泵浦功率为6.6 W时,激光输出达2.27 W,光-光转换效率为34.4%,斜效率达45%.利用KTP晶体进行腔内倍频,得到70 mW的0.67 μm激光输出.     

A One‐Kilobit PQR‐CMOS Smart Pixel Array

The photonic quantum ring (PQR) laser is a three dimensional whispering gallery (WG) mode laser and has anomalous quantum wire properties, such as microampere to nanoampere range threshold currents and √T‐dependent thermal red shifts. We observed uniform bottom emissions from a 1‐kb smart pixel chip of a 32×32 InGaAs PQR laser array flip‐chip bonded to a 0.35 µm CMOS‐based PQR laser driver. The PQR‐CMOS smart pixel array, now operating at 30 MHz, will be improved to the GHz frequency range through device and circuit optimization.     

670.7nm激光抽运下的祖母绿晶体激光运转实验研究

为了实现我国温差水热法生长的祖母绿晶体的激光运转,利用Nd∶YAP的1.3414μm激光经过LBO晶体倍频得到的670.7nm红光作为抽运光源,采用对称共焦腔实现了祖母绿晶体732nm红外激光的输出,激光阈值在0.5W~0.6W之间。在输入功率达到2.89W时获得了46μW的732nm激光输出。     

1.06微米脉冲激光对人体的损伤与安全防护问题

介绍利用电子显微镜观察波长1.06微米的脉冲激光在穿透软组织、骨板深部时所获得的人体红细胞受损的图象,并讨论了激光研究以及激光医疗中的安全防护问题。     

Optoacoustic Laser Stark spectroscopy and FIR laser action on CH3Br using a waveguide CO2 laser

The optoacoustic spectrum of CH₃Br around 10 μm band lines of a tunable cw waveguide CO₂ laser is investigated. Several new infrared absorptions are observed and most of the correspond ing molecular transitions are assigned. Far infra red laser action is reported by pumping with the same CO₂ laser: pump offsets are given using the Transferred Lambs dip (TLD) technique. A new FIR laser emission is obtained and assigned. An optoacoustic Laser Stark spectroscopy technique is used to investigate off resonance infrared tran sitions.     

半导体激光防护小麦幼苗紫外线-B辐射损伤的作用

用半导体激光(3.97 mW/mm2)和相干光及非相干光转换器(专利:CN2555523Y)将半导体激光转换为同功率、同波长和同光斑大小的非相干红光辐照小麦种子.通过分析幼苗期叶片DNA及生理变化,考察低剂量激光防护紫外线-B(UV-B)辐射损伤小麦幼苗的光效应.半导体激光预处理使10.08 kJ/m2UV-B辐射损伤小麦幼苗超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性,紫外吸收物含量、可溶性蛋白质含量、叶绿素a和叶绿素b含量及根长显著增加,丙二醛(MDA)含量显著降低.而非相干红光则不能.用酶联免疫(ELISA)方法检测小麦叶片DNA受UV-B辐射损伤产生的环丁烷嘧啶二聚体(CPD)含量,发现半导体激光能显著降低UV-B辐射损伤小麦细胞DNA中环丁烷嘧啶二聚体的含量,而非相干红光却不能使其降低.说明半导体激光防护UV-B辐射损伤小麦幼苗中光效应不起作用.     

Long period grating directional bend sensor based on asymmetric index modification of cladding

A long period grating (LPG) written in a standard optical fibre was modified by using a femtosecond laser to induce an asymmetric change in the cladding's refractive index. This device produced blue and red wavelength shifts depending on the orientation of applied curvature, with maximum sensitivities of -1.6 nm m and +3.8 nm m, suggesting that this type of LPG may be useful as a shape sensor.     

Dynamic characteristics of micro-optothermal expansion and optothermal microactuators

The dynamic characteristics of micro-optothermal (OT) expansion and novel OT microactuators are theoretically analysed using a heat transient model and finite element modelling thermal simulation. Three different-shaped microactuators are machined by an excimer laser micromachining system using a single layer material; first with a single OT expansion arm; second with a bi-direction microactuator (BDMA); and third with a bi-direction microswitch (BDMS). A red laser diode (650 nm) with a maximum power output of 30 mW and an adjustable frequency of 0?20 Hz is used as an irradiation light source. The experimental results show that the maximum response frequency of the OT microactuators can be at least 15 Hz, and the deflections of the BDMA (about 13 μm at 10 mW, 2 Hz) and the BDMS (about 10 μm at 8 mW, 2 Hz) are significantly magnified compared with the OT expansion (1.32 μm at 10 mW, 2 Hz) of the single arm, proving the feasibility of the enlarged bi-direction deflection/vibration of the microactuators. The expansion and deflection amplitude of the microactuators decrease as the laser frequency increases, and the experimental data and curves greatly agree with the theoretical predictions. The new method of OT microactuators can be widely applied in the fields where simple structure, easy fabrication, large displacement and wireless controlling are required.     

氮化硼薄膜的脉冲激光沉积

用Ｑ开关ＹＡＧ激光器的１．０６μｍ的脉冲激光在硅及玻璃衬底上沉积了氮化硼薄膜。做了ＳＥＭ，ＸＲＤ，红外透射谱和紫外一可见透射谱等测试。确认为六方氮化硼（ｈ－ＢＮ）薄膜．并测出其禁带宽度、晶格常数等。