共查询到20条相似文献,搜索用时 15 毫秒
1.
Stable continuous wave multi-wavelength operation of a stripe-array diode laser with an externalcavity spectral beam combining
geometry is presented. In this setup each emitter of the stripe-array is forced to operate at a different wavelength, which
leads to a decoupling between the usually phase-locked emitters. With a reflective diffraction grating with a period of 300
lines per mm, 33 equidistant laser lines around a center wavelength of 978 nm were realized, spanning a spectral range of
26 nm. With this novel approach near-diffraction limited emission with a beam quality of M
2 < 1.2 and an output power of 450 mW was achieved. This laser light source can be used for applications requiring low temporal
but high spatial coherence. 相似文献
2.
A first time O band Brillouin fiber laser is demonstrated and compared with the C band Brillouin fiber laser. By utilizing
a 20 km True wave fiber (TWF), the experiment demonstrated four Brillouin lines generated from the simple set-up of Brillouin
fiber laser. We compared the threshold between the Brillouin pump wavelength at 1310 nm which represent O band region and
1550 nm for C band region. It shows that the Brillouin threshold at O band region is smaller that C band. The channels spacing
between these two bands are also different, where O band have 12.72 GHz spacing while 1550 nm have 10.25 GHz spacing. 相似文献
3.
基于谱线匹配技术的星载成像光谱仪星上光谱定标方法研究 总被引:1,自引:0,他引:1
介绍了一种基于谱线匹配技术的星上光谱定标方法,该定标方法选取大气吸收线作为匹配谱线,采用相关系数法作为匹配结果判定条件标进行光谱定标。为模拟星上定标过程,将谱线匹配技术应用于振动试验后的成像光谱仪,振动试验可以模拟成像光谱仪在升空过程中受到的振动。星上光谱定标包括成像光谱仪分辨率的确定、面阵探测器光谱维和空间维像元中心波长的定标。由定标结果可知,振动试验后光谱仪分辨率为0.40 nm,与振动试验前相比没有发生变化;光谱维像元中心波长向长波偏移0.08 nm(小于一个像元);空间维像元光谱弯曲(光谱smile) 向短波方向弯曲,最大弯曲值为0.96 nm,近似于振动试验前光谱弯曲值。由此验证了谱线匹配技术进行星上光谱定标的可行性。 相似文献
4.
研制了一台高分辨率极紫外光谱仪,用于磁约束等离子体诊断。采用一块具有平场特性的全息球面变线距光栅作为分光元件,光栅公称线密度为1 200 lines·mm-1,掠入射角为3°。一台可深度制冷、背照式面阵CCD作为光谱探测器,用机械快门控制曝光时间。通过CCD在光谱聚焦面的移动,可以记录的光谱范围为5~50 nm。用Penning放电光源测试了光谱仪的性能; 利用光源的标准谱线,进行了波长标定,波长精度为0.003 nm,并计算出系统各参数的实际值;当入缝宽度设置为30 μm时,在20 nm附近,光谱分辨率达0.015 nm,达到设计指标。 相似文献
5.
从理论上研究了光谱线型函数的四种形式及其关系,以多普勒展宽导致的线型函数为例,分析了光子数、能量按频率及波长分布函数的最大值和半高全宽。结果表明,光子数、能量按频率的分布函数近似相等,光子数、能量按波长的分布函数也近似相等。通过对多普勒线型函数的分析,建立了根据两条光谱线的线型函数的最大值比值求得光子数比值的方法。 相似文献
6.
简述了偏振风成像干涉仪(PAMI)探测高层大气风场的基本原理;研究得出了多波长探测时偏振风成像干涉仪干涉强度、仪器调制度与位相延迟片的延迟位相之间的理论表达式;得出了偏振风成像干涉仪的干涉强度和仪器调制度受所探测谱线波长调制的重要结论;采用计算机模拟分析了使用偏振风成像干涉仪(设计谱线为高层大气氧原子跃迁时辐射的630nm的极光谱线)探测高层大气时各目标谱线的干涉强度和仪器调制度,给出了干涉强度和仪器调制度与探测谱线波长之间的关系,得出了732nm的极光谱线不适合用作探测目标的结论. 本文为高层大气风场探
关键词:
高层大气风场探测
偏振风成像干涉仪
调制度
多波长探测 相似文献
7.
Peroz C Calo C Goltsov A Dhuey S Koshelev A Sasorov P Ivonin I Babin S Cabrini S Yankov V 《Optics letters》2012,37(4):695-697
A novel type of multiband wavelength demultiplexer for on-chip spectroscopy applications is proposed, and first results of the device fabrication and characterization are reported. The devices are based on computer-designed digital planar holograms, which involve millions of lines specifically located and oriented in order to direct output light into designed focal channels according to the wavelength. Devices operate in four individual bandwidths within the visible range (477.2-478.0 nm, 528.8-529.9 nm, 586.4-587.7 nm, 628.9-630.4 nm) with 96 channels and spectral channel spacing down to 0.0375 nm/channel. 相似文献
8.
A radio-over-fiber (RoF) distribution system incorporating both sub-carrier multiplexing and wavelength division multiplexing (WDM) technologies is presented. This signal is directly modulated onto three high-speed lasers. Bragg filters are employed at the receiver base station in order to both demultiplex the required optical channel, and ensure that the detected signal is single side band (in order to overcome dispersion limitations of the link). System spectral efficiency is optimised by wavelength interleaving. The channel spacing between the WDM channels is varied and the system performance for different values of channel spacing and spectral efficiencies is investigated. The results show that wavelength interleaving is a reliable technique that could be used to increase the spectral efficiency of RoF systems. 相似文献
9.
L. S. Vasil’ev 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(4):471-475
A method is proposed for estimating the errors in determining the position of spectral lines, which takes into account possible errors of the measuring instrument and methods of mathematical treatment of spectra, as well as their dependence on the half-width of spectral lines, spacing between them, and the background noise height. 相似文献
10.
激光诱导击穿光谱(LIBS)技术具有非接触测量、无需样品预处理以及快速多元素同时分析等特点,适合于高温、高压、真空、有毒以及敌对环境等仪器和操作人员无法靠近观测对象的应用中。LIBS技术结合望远镜系统可以实现物质成分的远距离检测与分析。搭建了一套可自动聚焦的LIBS远程测量系统。该系统中的望远镜采用Schwarzschild结构,由一块凹球面反射镜和一块凸球面反射镜组成。两块球面反射镜共轴安装。其中凸面反射镜安装在电控精密平移台上,电动平移台可带动凸面反射镜沿光轴移动。通过调整凸面反射镜的位置,改变凸面反射镜和凹面反射镜的间距,进而改变系统的焦距,实现对不同距离的样品进行光谱测量。该结构的优点在于:激光聚焦光路与信号光采集光路相同,便于安装和调试;望远镜系统采用全反射式光路,适用于紫外波段检测;只包括两个球面反射镜,结构紧凑,元件容易加工。望远镜系统调焦距离为1.5~3.6 m,聚焦光斑直径约为0.5~1.0 mm。使用该系统对铜样品进行了LIBS实验,确认了Cu元素的特征谱线。通过测量Cu元素的LIBS特征谱线(Cu Ⅰ 223.01 nm, Cu Ⅰ 224.43 nm)峰面积和反射镜间距之间关系,得到了激光的最优聚焦位置。实验结果表明,该系统能够完成样品的远程激发和LIBS光谱测量,并能够对不同距离的样品进行自动聚焦。 相似文献
11.
A 32-channel 100 GHz wavelength division multiplexer by interleaving two silicon arrayed waveguide gratings 下载免费PDF全文
Changjian Xie 《中国物理 B》2021,30(12):120703-120703
A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings (AWGs). It has a parallel structure consisting of two silicon 16-channel AWGs with 200 GHz spacing and a Mach-Zehnder interferometer (MZI) with 200 GHz free spectral range. The 16 channels of one silicon AWG are interleaved with those of the other AWG in spectrum, but with an identical spacing of 200 GHz. For the composed wavelength division multiplexer, the experiment results reveal 32 wavelength channels in C-band, a wavelength spacing of 100 GHz, and a channel crosstalk lower than -15 dB. 相似文献
12.
A simple method of measuring the wavelength γ1 and the spectral line spacing Δγ of a multi-mode dye laser light by using the correlated speckle patterns produced at the far-field of a diffuser is proposed. Examples of the obtained values of γ1 and Δγ are 6.0 × 103 Å and 3.0 × 101 Å, respectively. 相似文献
13.
针对由YDFL和EDFL作为基频光源的QPM-DFG激光系统,利用PPMgLN晶体的色散关系及其温度特性,有效拓宽了QPM波长接受带宽.模拟结果表明,当采用1550和1060 nm波段的EDFL和YDFL分别作为DFG的信号和抽运光源时,对于相同的中红外波段,满足QPM条件所允许的抽运光波长变化范围远大于信号光波长变化范围.当固定信号光波长为1560 nm时,对于给定的晶体温度,1060 nm波段抽运光的QPM接受带宽超过17 nm,对应于中红外差频光带宽可约180 nm.采用多波长YDFL作为抽运源,单
关键词:
差频产生
准相位匹配
多波长中红外
光纤激光器 相似文献
14.
高光谱分辨率紫外平场光谱仪的研制 总被引:1,自引:0,他引:1
光栅作为一重要的分光元件,广泛应用于各类光谱仪,其中球面变线距平场光栅以其独特的平场特性使其容易与阵列探测器结合使用,一次实现宽光谱范围的记录。商业球面平场光栅一般只会提供光栅的公称线密度以及相应的安装参数,而不会提供光栅具体的变线距参数,并且提供的安装参数是针对整个使用波段优化的结果。使用者往往只需要其中的一部分波段。针对这种情况,根据球面平场光栅聚焦、分光原理,利用生产厂家提供的光学元件安装参数给出了推导球面变线距光栅变线距参数的方法。并给出了利用这些参数,根据光谱仪的实际工作波段确定最佳的CCD安装位置的方法。根据推导的光栅变线距参数可以对光学系统进行光学追迹已验证光学系统的性能。研制了一台高分辨率紫外平场光谱仪,覆盖光谱范围230~280 nm。采用的球面变线距光栅公称线密度为1 200 lines·mm-1,使用波段为170~500 nm。推导了该光栅的变线距参数,并针对230~280 nm波段对CCD的安装位置进行了优化。同时利用不同元素的标准光源空心阴极灯对光谱仪进行了波长标定和光谱分辨率测试。波长标定采用参数拟合法,整个波段范围内的标定精度优于0.01 nm。光谱分辨率测试的结果表明光谱仪的光谱分辨率达到0.08 nm@280.20 nm。 相似文献
15.
16.
J. Bačkovský 《Czechoslovak Journal of Physics》1965,15(10):752-759
The paper discusses the influence of statistical errors in measuring the intensity of a spectral line on the exact determination of its wavelength. Using simplifying assumptions, it is shown that the relative error in measuring the wavelengths of spectral lines of the same type, caused by the statistical character of X-ray intensity measurements and by the influence of the true width of the spectral line, is practically constant under the same conditions, i.e. it is independent of the lattice parameters of the crystals used and of the wavelength of the spectral line. It seems that the latest exact measurements of Bearden confirm this result.The greatest care should therefore be devoted to the neighbourhood of inflection points of the curve representing the spectral line profile when making exact measurements of the spectral position of the lines.The author heartily thanks Professor M. A. Blochin for valuable remarks on this work. 相似文献
17.
18.
V. S. Letokhov 《Optics & Laser Technology》1981,13(4):203-209
Applications of sub-Doppler optical resonances to the spectral lines of atoms and molecules giving laser standards of wavelength and frequency are presented. The problems of precise measurement of length and absolute measurement of light frequency are considered. Prospects of elaborating fundamental experiments with laser ultra-stable frequency are discussed. 相似文献
19.
We propose a wavelength-spacing tunable multi-wavelength fiber optical parametric oscillator (MW-FOPO) with a simple line
cavity and one pump source based on multiple four-wave mixing (MFWM). Stable multi-wavelength lasing at room temperature is
achieved due to the four-wave mixing effect and the broadband gain of the fiber optical parametric amplifier based on a highly
nonlinear fiber. The wavelength spacing of the proposed MW-FOPO can be tuned by adjusting the wavelength of the pump light
or the central wavelength of the fiber Bragg grating. Seventeen lasing lines with a wavelength spacing of 2.89 nm and an extinction
ratio larger than 10 dB, which covers the wavelength region from 1540 to 1568 nm is demonstrated. 相似文献