排序方式: 共有93条查询结果,搜索用时 171 毫秒
1.
2.
3.
4.
介绍双螺旋叠栅条纹检测光束准直性的基本原理,进一步就双螺旋叠栅条纹的特征参量与被测光束发散角(即光束准直精度)的关系进行分析和推导。在分析双螺旋叠栅条纹进行时,首先采用频域低通滤波提取纯叠栅条纹,然后提取纯叠栅条纹的特征参量。提出两种特征参量的提取方法,一种依次进行傅里叶变换计算相位信息的傅里叶变换方法,另一种是受传统时间相移算法启发而提出的空间相移算法,讨论了在两种方法中极坐标的重采样问题和相应的计算公式,并进行了计算机模拟。结果表明,傅里叶变换方法和空间相移算法实质都是获取叠栅条纹全场趋势的平均值,使最终光束发散角的检测具有很高的精度,对自成像条纹周期的检测误差在±2.8‰以内。 相似文献
5.
We present a systematic experimental investigation on visible light collimation by a nanostructured slit flanked with a pair of periodic array of grooves in gold thin film. A wide variety of aspects are considered, such as the polarization state, the transport path of incident light, the groove-groove spacing, the groove width and depth. Our results clearly show that the relationship between the collimation wavelength and the periodicity of the slit-groove structure accords well with the surface plasmon dispersion model proposed by previous researchers. Furthermore, the surface plasmon wave phase retardation effect induced by the surface structure is also verified via the measurement for samples with different groove widths and depths. These results indicate that the detailed geometry of the groove structure has obvious impacts on the collimation effect and the angular distribution of the diffraction light in the subwavelength plasmonic system. 相似文献
6.
Peter Oberta Peter Mikulík Martin Kittler Jaromir Hrdý 《Journal of synchrotron radiation》2011,18(3):522-526
Two crystals with precise parabolic holes were used to demonstrate sagittal beam collimation by means of a diffractive–refractive double‐crystal monochromator. A new approach is introduced and beam collimation is demonstrated. Two Si(333) crystals with an asymmetry angle of α = 15° were prepared and arranged in a dispersive position (+,?,?,+). Based on theoretical calculations, this double‐crystal set‐up should provide tunable beam collimation within an energy range of 6.3–18.8 keV (ΘB = 71–18.4°). An experiment study was performed on BM05 at ESRF. Using 8.97 keV energy, the beam profile at various distances was measured. The experimental results are in good agreement with theoretical predictions. Owing to insufficient harmonic suppression, the collimated (333) beam was overlapped by horizontally diverging (444) and (555) beams. 相似文献
7.
8.
激光束准直检测仪:原理,功能与精度 总被引:1,自引:1,他引:0
根据先前曾提出的单楔板旋转原理与实验研究,一种定量检测光学系统离焦量及激光发散度的仪器已经研制成功.本文概括地介绍了该仪器原理、主要功能、测试方法及精度评价等.由于本仪器具有一系列优点,已成为激光实验、光学教学及光学工程必备的仪器 相似文献
9.
分析人字形光栅副莫尔条纹的特点,研究了一种用莫尔偏折术检校光束准直性的改进方法,利用双场莫尔条纹方向平行性进行判定,此法使用方便且精度可提高一倍以上。 相似文献
10.