We report on a compact, stable, all-fiberized narrow-linewidth(0.045 nm) pulsed laser source emitting laser beam with a wavelength of 266 nm, and tunable pulse width and repetition rate. The system is based on all-fib...We report on a compact, stable, all-fiberized narrow-linewidth(0.045 nm) pulsed laser source emitting laser beam with a wavelength of 266 nm, and tunable pulse width and repetition rate. The system is based on all-fiberized nanosecond amplifier architecture, which consists of Yb-doped fiber preamplifiers and a super-large-mode-area Yb-doped fiber power amplifier. The fiber amplifier with a core of 50 μm is used to raise the threshold of the stimulated Brillouin scattering(SBS) effect and to obtain high output power and single pulse energy. Using lithium triborate(LBO) crystal and betabarium borate(BBO) crystal for realizing the second-harmonic generation(SHG) and fourth-harmonic generation(FHG),we achieve 17 μJ(1.73 W) and 0.66 μJ(66 mW), respectively, at wavelengths of 532 nm and 266 nm and a repetition rate of 100 kHz with pulse width of 4 ns. This source has great potential applications in fluorescence research and solar-blind ultraviolet optical communication.展开更多
为建立一种脱色评价的方法,以样品吸光度曲线的曲线下面积(area under the curve,AUC)作为脱色率计算依据,将AUC应用于枸杞多糖的脱色工艺考察中,探究枸杞多糖的最佳脱色工艺条件。采用紫外-可见分光光度计,在200~760 nm处对3种色素(原...为建立一种脱色评价的方法,以样品吸光度曲线的曲线下面积(area under the curve,AUC)作为脱色率计算依据,将AUC应用于枸杞多糖的脱色工艺考察中,探究枸杞多糖的最佳脱色工艺条件。采用紫外-可见分光光度计,在200~760 nm处对3种色素(原花青素、叶绿素铜钠、β-胡萝卜素)的溶液分别进行全波长扫描,采用Origin软件统计脱色前后样品液的AUC,用于计算脱色率。将AUC脱色计算方式引入到枸杞多糖的脱色工艺考察,筛选不同类型大孔树脂的脱色效果,并通过单因素与正交试验确定最佳脱色条件。结果表明:上述3种色素分别在0.98~31.25、3.92~125.00、0.39~12.50μg/mL范围内线性关系良好,R2≥0.998 6,平均加标回收率分别为101.86%、100.08%、100.68%,相对标准偏差(relative standard deviation,RSD)分别为2.66%、2.27%、2.55%。采用AUC脱色率计算方法,枸杞多糖粗品采用S8大孔树脂脱色,最佳脱色工艺条件为每100 mg多糖粗品使用S8树脂量为7.5 g、粗品浓度为3.0 g/L、在35℃下脱色时间为60 min。在该脱色工艺条件下,脱色率的平均值为73.01%,RSD为1.01%,说明稳定性良好。展开更多
New visible transparent, UV absorption, and high infrared reflection properties have been realized by depositing multilayer Si O2/Zn O: Al/Ce O2-Ti O2/Si O2 films onto glass substrates at low temperature by radio freq...New visible transparent, UV absorption, and high infrared reflection properties have been realized by depositing multilayer Si O2/Zn O: Al/Ce O2-Ti O2/Si O2 films onto glass substrates at low temperature by radio frequency magnetron sputtering. Optimum thickness of Si O2, Zn O: Al(ZAO) and Ce O2-Ti O2(CTO) films were designed with the aid of thin film design software. The degree of antireflection can be controlled by adjusting the thickness and refractive index. The outer Si O2 film can diminish the interference coloring and increase the transparency; the inner Si O2 film improves the adhesion of the coating on the glass substrate and prevents Ca2+, Na+ in the glass substrate from entering the ZAO film. The average transmittance in the visible light range increases by nearly 18%-20%, as compared to double layer ZAO/CTO films. And the films display high infrared reflection rate of above 75% in the wavelength range of 10-25 μm and good UV absorption(> 98%) properties. These systems are easy to produce on a large scale at low cost and exhibit high mechanical and chemical durability. The triple functional films with high UV absorption, antireflective and high infrared reflection rate will adapt to application in flat panel display and architectural coating glass, automotive glass, with diminishing light pollution as well as decreasing eye fatigue and increasing comfort.展开更多
An AIGaN-based back-illuminated ultraviolet p-i-n detector is designed and its performance is analysed both simulately and experimentally. The width of p- and i-regions has been optimized to the best theoretic values....An AIGaN-based back-illuminated ultraviolet p-i-n detector is designed and its performance is analysed both simulately and experimentally. The width of p- and i-regions has been optimized to the best theoretic values. It is indicated that the changing of responsivity with increase of bias can not be attributed to the expansion of depletion layer as it is believed, but to two reasons： 1） the effect of GaN/AlGaN heterojunction barrier to block the electrons decreases with higher bias and 2） the recombination rate of excess carriers decreases due to the building up of an electric field in depletion region. At zero bias, the simulated responsivity reaches its maximum of 0.12 A/W with quantum efficiency of 55.1%. The measured peak responsivity is more than 0.09 A/W with quantum efficiency greater than 41.6%. The experimental data are almost consistent with the results of the simulation.展开更多
基金Project supported by the Key Program of Beijing Municipal Natural Science Foundation, China (Grant No. KZ201910005006)the National Nature Science Foundation of China (Grant No. 62005004)+1 种基金the Natural Science Foundation of Beijing Municipality, China (Grant No. 4204091)the National Science Foundation for Postdoctor Scientists of China (Grant No. 212423)。
文摘We report on a compact, stable, all-fiberized narrow-linewidth(0.045 nm) pulsed laser source emitting laser beam with a wavelength of 266 nm, and tunable pulse width and repetition rate. The system is based on all-fiberized nanosecond amplifier architecture, which consists of Yb-doped fiber preamplifiers and a super-large-mode-area Yb-doped fiber power amplifier. The fiber amplifier with a core of 50 μm is used to raise the threshold of the stimulated Brillouin scattering(SBS) effect and to obtain high output power and single pulse energy. Using lithium triborate(LBO) crystal and betabarium borate(BBO) crystal for realizing the second-harmonic generation(SHG) and fourth-harmonic generation(FHG),we achieve 17 μJ(1.73 W) and 0.66 μJ(66 mW), respectively, at wavelengths of 532 nm and 266 nm and a repetition rate of 100 kHz with pulse width of 4 ns. This source has great potential applications in fluorescence research and solar-blind ultraviolet optical communication.
文摘为建立一种脱色评价的方法,以样品吸光度曲线的曲线下面积(area under the curve,AUC)作为脱色率计算依据,将AUC应用于枸杞多糖的脱色工艺考察中,探究枸杞多糖的最佳脱色工艺条件。采用紫外-可见分光光度计,在200~760 nm处对3种色素(原花青素、叶绿素铜钠、β-胡萝卜素)的溶液分别进行全波长扫描,采用Origin软件统计脱色前后样品液的AUC,用于计算脱色率。将AUC脱色计算方式引入到枸杞多糖的脱色工艺考察,筛选不同类型大孔树脂的脱色效果,并通过单因素与正交试验确定最佳脱色条件。结果表明:上述3种色素分别在0.98~31.25、3.92~125.00、0.39~12.50μg/mL范围内线性关系良好,R2≥0.998 6,平均加标回收率分别为101.86%、100.08%、100.68%,相对标准偏差(relative standard deviation,RSD)分别为2.66%、2.27%、2.55%。采用AUC脱色率计算方法,枸杞多糖粗品采用S8大孔树脂脱色,最佳脱色工艺条件为每100 mg多糖粗品使用S8树脂量为7.5 g、粗品浓度为3.0 g/L、在35℃下脱色时间为60 min。在该脱色工艺条件下,脱色率的平均值为73.01%,RSD为1.01%,说明稳定性良好。
基金Funded by the Natural Science Foundation of Hubei Province(No.2014CFB563)the key Technology Innovation Project of Hubei Province(No.2013AAA005)China Postdoctoral Science Foundation(Nos.2013T60752 and 2012M511689)
文摘New visible transparent, UV absorption, and high infrared reflection properties have been realized by depositing multilayer Si O2/Zn O: Al/Ce O2-Ti O2/Si O2 films onto glass substrates at low temperature by radio frequency magnetron sputtering. Optimum thickness of Si O2, Zn O: Al(ZAO) and Ce O2-Ti O2(CTO) films were designed with the aid of thin film design software. The degree of antireflection can be controlled by adjusting the thickness and refractive index. The outer Si O2 film can diminish the interference coloring and increase the transparency; the inner Si O2 film improves the adhesion of the coating on the glass substrate and prevents Ca2+, Na+ in the glass substrate from entering the ZAO film. The average transmittance in the visible light range increases by nearly 18%-20%, as compared to double layer ZAO/CTO films. And the films display high infrared reflection rate of above 75% in the wavelength range of 10-25 μm and good UV absorption(> 98%) properties. These systems are easy to produce on a large scale at low cost and exhibit high mechanical and chemical durability. The triple functional films with high UV absorption, antireflective and high infrared reflection rate will adapt to application in flat panel display and architectural coating glass, automotive glass, with diminishing light pollution as well as decreasing eye fatigue and increasing comfort.
文摘An AIGaN-based back-illuminated ultraviolet p-i-n detector is designed and its performance is analysed both simulately and experimentally. The width of p- and i-regions has been optimized to the best theoretic values. It is indicated that the changing of responsivity with increase of bias can not be attributed to the expansion of depletion layer as it is believed, but to two reasons： 1） the effect of GaN/AlGaN heterojunction barrier to block the electrons decreases with higher bias and 2） the recombination rate of excess carriers decreases due to the building up of an electric field in depletion region. At zero bias, the simulated responsivity reaches its maximum of 0.12 A/W with quantum efficiency of 55.1%. The measured peak responsivity is more than 0.09 A/W with quantum efficiency greater than 41.6%. The experimental data are almost consistent with the results of the simulation.
