共查询到20条相似文献,搜索用时 218 毫秒
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本文讨论在计算机数控机床上用硬质材料研磨非球面模具,以及用触针技术测量模具的形状。对用这些模具复制的NA=0.45透镜进行了测量,在波长为780nm时,得到小于0.030波长的光程差均方根值。 相似文献
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物像等大法测量双棱镜干涉中虚光源间距 总被引:1,自引:0,他引:1
对菲涅耳双棱镜干涉测钠光波长实验中应用二次成像法测量双虚光源间距的相对误差进行分析,指出小像的测量误差是影响测量双虚光源间距的主要因素,提出改用当虚光源位于透镜前2倍焦距时物像等大的测量方法,可较为准确的测量双虚光源间距和双虚光源到测微目镜的分划板的距离. 相似文献
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一种利用傅立叶频谱测量透镜焦距的新方法 总被引:2,自引:0,他引:2
本文介绍了一种利用傅立叶频谱测量球面透镜、柱面透镜及环曲面透镜单色光焦距的新方法,这种新方法不需要高精度的平行光管,用激光器作为光源,仪器调式简单,测量结果可靠,测量精度可达0.3%。如果采用光电扫描及微机处理,这种方法还可以实现自动化测量,而且可以测量不可见光工作情况下的透镜焦距。 相似文献
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现有的焦距检测方法通常由于检测仪器光源波长与光学系统不完全匹配从而产生纵向色差影响检测结果。针对这一问题,研究光学系统纵向色差的变化规律,并确定在400 nm~1 000 nm波段用于表示其函数关系的Conrady公式和复消色差特性公式。根据光学系统近焦位置的离焦量与位置呈线性关系的特性, 提出使用菲索干涉仪测量5种不同波长的焦距位置,获得单透镜和双胶合镜头的纵向色差曲线。实验结果表明: 在400 nm~1 000 nm波段单色系统和消色差系统的纵向色差的函数关系分别符合Conrady公式和复消色差特性公式,研究结果为焦距的理论计算和精确检测提供了新的思路和参考。 相似文献
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A novel means of focal length measurement is proposed based upon Hartmann–Shack principle of wavefront detection. Mathematical approaches of focal length measurement are deduced without the necessity of knowing the position of lens principle plane. In experiment, laser sources with wavelength of 633 nm and 780 nm are separately used and focal length of three pieces of doublets is measured under two wavelengths mentioned above. As were shown by the results, this method of focal length measurement could not only accurately measure lens focal length, but also evaluate chromatic aberration of them. Since the intensity of light is detected by CCD, optical characteristics of lens beyond the range of visible light are also measurable when response range of CCD allows. This new means of focal length measurement is characterized by high accuracy, fast measuring and easy to setup, thereby, it is applicable in wide fields of area. 相似文献
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研究了一种全新的纳米尺度位移测量系统。将双折射元件插入He-Ne激光器谐振腔内产生频率分裂效应,使原本单模谐振的激光器输出变成了频差可调的2个正交偏振频率(o光和e光),而形成双频激光器。在激光谐振腔外放置沿激光轴线位移的反射表面,将输出的激光束反射回腔内,以便对激光的光强进行调制,可实现高分辨率非接触式可判向位移测量。提出了一种细分方法,该方法突破了传统干涉系统的衍射极限(1/2波长)。对于633nm波长He-Ne激光,本系统的理想分辨率为1/8波长(约为79nm)。 相似文献
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为确定飞秒激光光束对微尺度结构的烧蚀深度,研究了给定功率条件下对应的激光束有效烧蚀焦距。提出采用激光焦点处获得的烧痕阵列图像及在离焦状态下提取烧痕图像特征,通过分析图像特征与离焦距离,获得激光束有效烧蚀焦距范围的方法。在激光束焦点附近的硅晶片表面烧蚀出斑痕阵列,向下逐渐减小焦距,采集硅晶片斑痕图像,提取斑痕平均像素面积及斑痕目标与背景之间的R分量灰度差,获得斑痕像素面积及灰度差随激光束焦距变化的曲线;向上逐渐增大焦距,提取并获得斑痕像素面积及灰度差随激光束焦距变化的曲线。结合激光束向下离焦阈值(633 μm)及向上离焦阈值(993 μm),确定20 mW输出功率条件下,飞秒激光在硅晶片材料表面的有效烧蚀深度为360 μm。采用中位值方法确定了激光束在硅晶片表面聚焦时的焦距为0.823 mm。实验表明,激光烧蚀斑痕像素面积及灰度差与激光束焦距之间的关系能够客观地反映激光束有效烧蚀焦距的变化范围。 相似文献
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Precise determination of characteristic laser frequencies by an Er-doped fiber optical frequency comb
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Shiying Cao 《中国物理 B》2022,31(7):74207-074207
Femtosecond optical frequency combs correlate the microwave and optical frequencies accurately and coherently. Therefore, any optical frequency in visible to near-infrared region can be directly traced to a microwave frequency. As a result, the length unit "meter" is directly related to the time unit "second". This paper validates the capability of the national wavelength standards based on a home-made Er-doped fiber femtosecond optical frequency comb to measure the laser frequencies ranging from visible to near-infrared region. Optical frequency conversion in the femtosecond optical frequency comb is achieved by combining spectral broadening in a highly nonlinear fiber with a single-point frequency-doubling scheme. The signal-to-noise ratio of the beat notes between the femtosecond optical frequency comb and the lasers at 633, 698, 729, 780, 1064, and 1542 nm is better than 30 dB. The frequency instability of the above lasers is evaluated by using a hydrogen clock signal with a instability of better than 1×10-13 at 1-s averaging time. The measurement is further validated by measuring the absolute optical frequency of an iodine-stabilized 532-nm laser and an acetylene-stabilized 1542-nm laser. The results are within the uncertainty range of the international recommended values. Our results demonstrate the accurate optical frequency measurement of lasers at different frequencies using the femtosecond optical frequency comb, which is not only important for the precise and accurate traceability and calibration of the laser frequencies, but also provides technical support for establishing the national wavelength standards based on the femtosecond optical frequency comb. 相似文献
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介绍了1.3 μm/1.5 μm光纤激光功率溯源至低温辐射计的测量方法,与传统溯源至绝对辐射计的方法相比较,最终利用低温辐射计法通过633 nm波长稳定光源标定陷阱式探测器,然后用陷阱式探测器将量值传递到陷阱式量传探测器,最后通过1310 nm/1550 nm通信用光功率稳定光源通过热释电光功率计标定InGaAs光电探测器并用于测量光纤功率。实验结果表明,溯源至低温辐射计的光纤功率测量方法在1310 nm及1550 nm波长点处对一标准光功率计修正系数测量的相对标准差分别为0.0011及0.0007,其测量不确定度可优于0.6%(k=2),在保证量值一致性的同时有效降低了测量不确定度,提高量值传递精度。 相似文献
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M. Reese B. Schäfer P. Großmann A. Bayer K. Mann T. Liese H. U. Krebs 《Applied Physics A: Materials Science & Processing》2011,102(1):85-90
The focusing properties of a one-dimensional multilayer Laue lens (MLL) were investigated using monochromatic soft X-ray radiation
from a table-top, laser-produced plasma source. The MLL was fabricated by a focused ion beam (FIB) structuring of pulsed laser
deposited ZrO2/Ti multilayers. This novel method offers the potential to overcome limitations encountered in electron lithographic processes.
Utilizing this multilayer Laue lens, a line focus of XUV radiation from a laser-induced plasma in a nitrogen gas puff target
could be generated. The evaluated focal length is close to the designed value of 220 μm for the measurement wavelength of
2.88 nm. Divergence angle and beam waist diameter are measured by a moving knife edge and a far-field experiment, determining
all relevant second-order moments based beam parameters. The waist diameter has been found to be approximately 370 nm (FWHM). 相似文献
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采用正交几何配置的双波长双脉冲激光烧蚀-激光诱导击穿光谱技术准确测量了铝合金样品的激光烧蚀阈值。在烧蚀激光波长为532 nm、脉宽为12 ns并采用焦距为2 cm的非球面透镜强聚焦的条件下,得到铝合金的激光能量烧蚀阈值为48 J,等效的能量密度烧蚀阈值为9.8 J/cm2。该技术是一种新的激光烧蚀阈值的光谱测量手段,与传统的测量技术相比,具有高灵敏、准确、快捷和便利的特点,可以用于不同材料的激光烧蚀阈值的准确测量。 相似文献
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A dual-wavelength parallel interferometer for subnanometer displacement measurement is introduced. A synthetic wavelength is used to subdivide the fringes formed by a single wavelength. An experimental setup that uses a heat-stabilizing dual-wavelength 633-nm He-Ne laser as the light source is established. The primary experimental result shows that a resolution of 0.210 nm over a 350-nm range has been achieved. 相似文献