We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase sec...We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing （QWI） technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature.展开更多
This paper describes a tunable dual-wavelength Ti：sapphire laser system with quasi-continuous-wave and high-power outputs. In the design of the laser, it adopts a frequency-doubled Nd：YAG laser as the pumping source...This paper describes a tunable dual-wavelength Ti：sapphire laser system with quasi-continuous-wave and high-power outputs. In the design of the laser, it adopts a frequency-doubled Nd：YAG laser as the pumping source, and the birefringence filter as the tuning element. Tunable dual-wavelength outputs with one wavelength range from 700 nm to 756.5 nm, another from 830 nm to 900mn have been demonstrated. With a pump power of 23 W at 532 nm, a repetition rate of 7 kHz and a pulse width of 47.6 ns, an output power of 5.1 W at 744.8 nm and 860.9 nm with a pulse width of 13.2 ns and a line width of 3 nm has been obtained, it indicates an optical-to-optical conversion efficiency of 22.2%.展开更多
We report on the generation of dual-wavelength dissipative solitons in a passively mode-locked fibre laser with a net normal dispersion using the nonlinear polarization rotation （NPR） technique. Taking the intrinsic...We report on the generation of dual-wavelength dissipative solitons in a passively mode-locked fibre laser with a net normal dispersion using the nonlinear polarization rotation （NPR） technique. Taking the intrinsic advantage of the intracavity birefringence-induced spectral filtering effect in the NPR-based ring laser cavity, the dual-wavelength dissipative solitons are obtained. In addition, the wavelength separation and the lasing location of the dual-wavelength solitons can be flexibly tuned by changing the orientation of the polarization controller.展开更多
A diode-end-pumped Nd：YAG dual-wavelength laser operating at 1319 and 1338 nm is demonstrated. The maximum average output power of the quasi-continuous wave linearly polarized dual-wavelength laser is obtained to be ...A diode-end-pumped Nd：YAG dual-wavelength laser operating at 1319 and 1338 nm is demonstrated. The maximum average output power of the quasi-continuous wave linearly polarized dual-wavelength laser is obtained to be 2.1 W at a repetition rate of 50 kHz with an output power instability of less than 0.38% and beam quality factor M^2 of 1.45. Using the two lines, the highly coherent and narrow linewidth terahertz radiation of 3.23 THz can be generated in an organic 4-N, N-dimethylamino-methyl-stilbazolium tosylate （DAST） crystal. Meanwhile, the multi-wavelength red laser at 659.5, 664 and 669 nm is generated by frequency doubling and sum frequency processes in a lithium triborate （LBO） crystal. The average red laser output power is enhanced up to 1.625 W at a repetition rate of 15 kHz with an output power instability of better than 0.53% and beam quality factor M^2 of 6.05. Using the three lines, it is possible to generate the multi-wavelength THz radiation of 3.3, 3.43 and 6.73 THz in an appropriate difference frequency crystal.展开更多
A low cost and simply fabricated reflective graphene oxide is successfully made. By using this absorber, as well as an end reflector, we obtain a passively mode-locked Yb：LuYSiO5 laser operating at nearly 1 p,m. When...A low cost and simply fabricated reflective graphene oxide is successfully made. By using this absorber, as well as an end reflector, we obtain a passively mode-locked Yb：LuYSiO5 laser operating at nearly 1 p,m. When the pump power is increased up to 5.73 W, stable mode locking is achieved. The central wavelength of the laser spectrum is 1043.2 nm with a pulse duration of 5.0 ps. When the pump power reaches 8.16 W, dual-wavelength mode locking laser pulses at 1036.3 nm and 1043.5 nm are simultaneously detected.展开更多
目的研究超皮秒双波长1064 nm联合532 nm点阵激光治疗黄褐斑的疗效与安全性。方法回顾性分析于2019年1月至2022年12月来广州市皮肤病防治所激光科就诊的黄褐斑患者45例,均为女性,年龄(40.6±2.4)岁,采用超皮秒双波长1064 nm联合532...目的研究超皮秒双波长1064 nm联合532 nm点阵激光治疗黄褐斑的疗效与安全性。方法回顾性分析于2019年1月至2022年12月来广州市皮肤病防治所激光科就诊的黄褐斑患者45例,均为女性,年龄(40.6±2.4)岁,采用超皮秒双波长1064 nm联合532 nm点阵激光治疗,每4周治疗1次,共治疗3次,采用黄褐斑面积和严重指数(Melasma Area and Severity Index,MASI)评分,VISIA检测正面紫外线斑、棕色斑、斑点、红斑计数分值,医生整体评价法(Physician Global Assessment,PGA)观察疗效,评估不良反应。采用重复测量设计的方差分析、配对t检验。结果治疗3次后PGA评分显示完全清除2例(4.4%),基本清除2例(4.4%),明显改善5例(11.1%),中度改善19例(42.2%),轻度改善15例(33.3%),无改善1例(2.2%),较治疗前加重1例(2.2%),改善率达95.6%。治疗前及治疗1次、2次、3次后MASI评分差异有统计学意义(F=7.2870,P=0.0002);与基线值[(19.32±10.36)分]相比,治疗2次后[(12.13±7.27)分,t=2.9190,P=0.0049]、治疗3次后MASI评分[(9.49±6.65)分,t=4.3720,P<0.0001]均明显下降。VISIA棕色斑分值治疗前后差异有统计学意义(F=5.3610,P=0.0005);在3次治疗后[(22.24±7.84)分]较基线值[(29.06±8.72)分]出现下降(t=3.5790,P=0.0007);红色斑分值治疗前后差异有统计学意义(F=5.0720,P=0.0007),与基线值[(18.80±9.51)分]比较,在治疗2次[(14.09±7.18)分,t=3.1640,P=0.0022]、3次后[(13.26±8.49)分,t=3.2290,P=0.0019]均明显下降。患者术中出现轻度疼痛,术后出现轻度红斑、水肿、色素沉着,均在2~7 d内消退,无水疱疤痕。结论超皮秒双波长点阵激光治疗黄褐斑疗效确切,安全性好。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60736036 and 61021003)the National Basic Research Program of China (Grant No. 2011CB301702)
文摘We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing （QWI） technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature.
基金Project supported in part by the National Natural Science Foundation of China （Grant Nos 10474071, 60637010, 60671036 and 60278001） and Tianjin Applied Fundamental Research Project, China （07JCZDJC05900）.
文摘This paper describes a tunable dual-wavelength Ti：sapphire laser system with quasi-continuous-wave and high-power outputs. In the design of the laser, it adopts a frequency-doubled Nd：YAG laser as the pumping source, and the birefringence filter as the tuning element. Tunable dual-wavelength outputs with one wavelength range from 700 nm to 756.5 nm, another from 830 nm to 900mn have been demonstrated. With a pump power of 23 W at 532 nm, a repetition rate of 7 kHz and a pulse width of 47.6 ns, an output power of 5.1 W at 744.8 nm and 860.9 nm with a pulse width of 13.2 ns and a line width of 3 nm has been obtained, it indicates an optical-to-optical conversion efficiency of 22.2%.
基金supported by the National Natural Science Foundation of China(Grant No.11074078)the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant No.20094407110002)+1 种基金the Foundation for Distinguished Young Talents in Higher Education of Guangdong,China(Grant No.C10183)the Key Program for Scientific and Technological Innovations of Higher Education Institutes in Guangdong Province,China(Grant No.cxzdlOll)
文摘We report on the generation of dual-wavelength dissipative solitons in a passively mode-locked fibre laser with a net normal dispersion using the nonlinear polarization rotation （NPR） technique. Taking the intrinsic advantage of the intracavity birefringence-induced spectral filtering effect in the NPR-based ring laser cavity, the dual-wavelength dissipative solitons are obtained. In addition, the wavelength separation and the lasing location of the dual-wavelength solitons can be flexibly tuned by changing the orientation of the polarization controller.
基金supported by the National Basic Research Program of China (Grant No 2007CB310403)the Tianjin Municipal Primary application and Frontier Technology Research Plan,China (Grant No 07JCYBJC06200)
文摘A diode-end-pumped Nd：YAG dual-wavelength laser operating at 1319 and 1338 nm is demonstrated. The maximum average output power of the quasi-continuous wave linearly polarized dual-wavelength laser is obtained to be 2.1 W at a repetition rate of 50 kHz with an output power instability of less than 0.38% and beam quality factor M^2 of 1.45. Using the two lines, the highly coherent and narrow linewidth terahertz radiation of 3.23 THz can be generated in an organic 4-N, N-dimethylamino-methyl-stilbazolium tosylate （DAST） crystal. Meanwhile, the multi-wavelength red laser at 659.5, 664 and 669 nm is generated by frequency doubling and sum frequency processes in a lithium triborate （LBO） crystal. The average red laser output power is enhanced up to 1.625 W at a repetition rate of 15 kHz with an output power instability of better than 0.53% and beam quality factor M^2 of 6.05. Using the three lines, it is possible to generate the multi-wavelength THz radiation of 3.3, 3.43 and 6.73 THz in an appropriate difference frequency crystal.
基金support by the National Natural Science Foundation of China (Grant No. 61078032)the Science and Technology Projects Plan of Jinan City, China (Grant No. 201004007)+2 种基金the State Key Laboratory of Crystal Materials, China (Grant No. KF1201)the Research Grants Council of Hong Kong, China (Grant No. GRF 526511 PolyU code: B-Q26E)the Hong Kong Polytechnic University, China (Grant No. G-YJ20)
文摘A low cost and simply fabricated reflective graphene oxide is successfully made. By using this absorber, as well as an end reflector, we obtain a passively mode-locked Yb：LuYSiO5 laser operating at nearly 1 p,m. When the pump power is increased up to 5.73 W, stable mode locking is achieved. The central wavelength of the laser spectrum is 1043.2 nm with a pulse duration of 5.0 ps. When the pump power reaches 8.16 W, dual-wavelength mode locking laser pulses at 1036.3 nm and 1043.5 nm are simultaneously detected.
文摘目的研究超皮秒双波长1064 nm联合532 nm点阵激光治疗黄褐斑的疗效与安全性。方法回顾性分析于2019年1月至2022年12月来广州市皮肤病防治所激光科就诊的黄褐斑患者45例,均为女性,年龄(40.6±2.4)岁,采用超皮秒双波长1064 nm联合532 nm点阵激光治疗,每4周治疗1次,共治疗3次,采用黄褐斑面积和严重指数(Melasma Area and Severity Index,MASI)评分,VISIA检测正面紫外线斑、棕色斑、斑点、红斑计数分值,医生整体评价法(Physician Global Assessment,PGA)观察疗效,评估不良反应。采用重复测量设计的方差分析、配对t检验。结果治疗3次后PGA评分显示完全清除2例(4.4%),基本清除2例(4.4%),明显改善5例(11.1%),中度改善19例(42.2%),轻度改善15例(33.3%),无改善1例(2.2%),较治疗前加重1例(2.2%),改善率达95.6%。治疗前及治疗1次、2次、3次后MASI评分差异有统计学意义(F=7.2870,P=0.0002);与基线值[(19.32±10.36)分]相比,治疗2次后[(12.13±7.27)分,t=2.9190,P=0.0049]、治疗3次后MASI评分[(9.49±6.65)分,t=4.3720,P<0.0001]均明显下降。VISIA棕色斑分值治疗前后差异有统计学意义(F=5.3610,P=0.0005);在3次治疗后[(22.24±7.84)分]较基线值[(29.06±8.72)分]出现下降(t=3.5790,P=0.0007);红色斑分值治疗前后差异有统计学意义(F=5.0720,P=0.0007),与基线值[(18.80±9.51)分]比较,在治疗2次[(14.09±7.18)分,t=3.1640,P=0.0022]、3次后[(13.26±8.49)分,t=3.2290,P=0.0019]均明显下降。患者术中出现轻度疼痛,术后出现轻度红斑、水肿、色素沉着,均在2~7 d内消退,无水疱疤痕。结论超皮秒双波长点阵激光治疗黄褐斑疗效确切,安全性好。
