二元光栅照明对光刻系统成象特性的影响

针对光刻系统分辨力和焦深的矛盾,详细研究了二元光栅照明对硅片上光强以及对光刻系统传输频率的影响,结果表明,二元光栅照明可显著提高光强的对比度,改善成象系统的频率传递函数,是一种比较理想的离轴照明技术。     

光栅纳米测量技术及应用

本文简要介绍了光栅纳米测量技术的主要研究内容，着重阐述了其应用实例－一种光栅纳米测微仪的原理结构和实现方法。从系统的重复性、分辨力和准确度三方面入手，深入地研究和探索解决光栅纳米测量过程中的各种关键技术问题的方法和途径，能够有效地将光栅测量的分辨力和准确度从亚微米量级提高到纳米量级。     

长光栅数显表5μm分辨力的实现方法

长光栅数显表５μｍ分辨力的实现方法张艺（青岛经济技术开发区电子技术公司，青岛２６６０７１）长光栅数显表的分辨力很高。数显表中显示１０μｍ、１μｍ，末位采用十进制计数，译码即可实现。而显示５μｍ、２μｍ则需要一些特殊方法。本文介绍一种长光栅数显表５０μ...     

基于光栅条纹强度分析的自动三维面形测量

通过对光栅条纹强度的分析，研究了一种自动三维面形测量技术。对发散照明所产生的光栅图形强度进行分析并得到被还原的相位。由于测量中只需一幅图象，因此该技术既简单又具有测速度快，精度较高的特点。文中还给出了理论模拟和实验结果。     

光栅内插值细分及补偿

本主要给出光栅输出原始信号的正弦分量中提取与光栅刻线间距的有关数字信息以及将其间的正弦模拟量采样量化经分后进行内插值补偿运算。可提高光栅传感器测量准确度和分辨力。     

大量程高性能光栅位移测量技术

高精度光栅位移测量系统具有纳米级重复精度、环境适应性强、维度易于扩展等优点,可以满足精密制造行业对米级测量量程、亚微米级精度与多维测量能力融合的测量技术要求,在高端制造、精密仪器等领域有重要应用。通过对测量光栅的各项参数进行研究,提升了测量光栅的尺寸与制作精度;提出高精度锥面衍射光栅位移测量、高倍细分转向干涉光栅位移测量、“品”字形拼接大量程光栅位移测量等技术,实现了数百毫米测量量程亚微米级测量精度。从光栅制作到测量系统研制对提升精度、分辨力及量程提供了理论分析与技术验证。     

超微细光刻中偏振光成像研究

在大数值孔径、短波长的投影光学光刻系统中，对S偏振光、P偏振光和非偏振光在硅片上的成像进行了研究，发现S偏振光成像具有最高的光强对数斜率值和最大的对比度；模拟了S偏振光通过掩模的电场分布机理，结果表明，可以通过调制照明光的偏振性来提高成像对比度和分辨力。     

光栅微振动测试传感技术的研究

提出了一种微弱地震波信号新的检波理论和方法．设计了一种测微振动传感器，采用光栅谐振子为敏感元件，将地震的机械信号转换成光调制信号——莫尔条纹，再用光电器件将其转换成数字化电信号．采用80倍细分技术，使传感器分辨力达到125nm；用MATLAB软件对PIC单片机记录的信号进行振动过程重构．结构中设计了横向限振片和光栅调节器，对光栅间隙、光栅间纵横向夹角进行调节，有效地限制了光栅间隙及角度的变化产生的误差．同时也校正了光栅的累积误差．有效地抑制了横向振动，提高了系统精度，同时可降低对该系统的横向限振要求，有利于结构设计．由于该传感器直接将地震的机械信号以脉冲数字信号输出，避免了器件精度不同对传感器输出数据质量的影响，简化了组装工艺．重点介绍了光栅数字地震检波器的结构设计、理论分析、辨向细分技术等．最后给出了测试数据和结论．     

X形测力元件标准测力仪

介绍一种配置了分辨力为 0 .1μm的光栅位移传感器作为测量装置的标准测力仪。     

成像式光栅自准直测角方法研究

针对目前光电自准直仪难以做到既有高分辨力同时又有大的测量范围的不足,提出一种成像式光栅自准直测角方法。该方法将成像式光栅方法、自准直测角技术相结合,利用标尺光栅像和指示光栅形成的光栅副反映被测物体的角度变化。试验结果表明,该系统接收到的光栅信号稳定,满足光栅计数的要求,成像式光栅自准直测角方法原理可行。该方法避免了光栅副间隙带来的误差,具有大量程及较高的分辨力。     

Analysis of direct three-dimensional image transmission through optical fibers by the use of coherence methods

The use of a grating interferometer under spatially incoherent illumination for direct three-dimensional image transmission through optical fibers is analyzed. The issues of resolution, image depth, and signal-to-noise ratio are addressed. Experimental results are presented.     

Reduced depth of field in incoherent hybrid imaging systems

A hybrid imaging system combines a modified optical imaging module and a digital postprocessing step. We define what to our knowledge is a new metric to quantify the blurring of a defocused image that is more suitable than the defocus parameter for describing defocused hybrid imaging systems. We use this metric to design a pupil phase grating to reduce the depth of field, thereby increasing the axial resolution, of an incoherent hybrid imaging system using quasi-monochromatic illumination. By introducing this grating at the exit pupil and digitally processing the output of the detector, we reduce the depth of field by more than a factor of 2. Finally, we examine the effect of using a CCD optical detector, instead of an ideal optical detector, on the reduction of the depth of field.     

Influence of several grating sensor parameters on the modulation depth of moiré signals under incoherent illumination

Theoretical expressions for the modulation depth of moiré signals under incoherent illumination are derived. Consequently, the modulation depth of a moiré signal is related to the following factors: the geometric shape and the size of the light source; the diffraction effect of the grating, which relates to the number of lines in the grating; the line and the space ratio; the grating pair gap; the geometric shape and the size of the receiving window; etc. In addition, the influence of the grating pair on the period and the inclination of moiré fringes under noncollimated illumination are discussed, and the changes in the moiré signal modulation depth under noncollimated illumination with that under collimated illumination are made. Finally, some experimental results are given to verify the theoretical expressions. This research is useful for the actual design of grating sensors.     

Metallic cylindrical focusing micromirrors with long axial focal depth or increased lateral resolution

Using a general focal-length function, two-dimensional long-focal-depth (LFD) metallic cylindrical focusing micromirrors (MCFMs) are designed and the focal performance is systematically investigated based on rigorous electromagnetic theory and the boundary element method. For a positive preset focal depth, simulation results reveal that the designed MCFMs still possess an LFD property and high lateral resolution even when the f-number is reduced to f/0.3. On the other hand, through setting the preset focal depth to be negative, increased lateral resolution is obtained, compared with the conventional MCFM. In addition, under multiwavelength illumination, a large common LFD region is demonstrated for the designed LFD MCFMs, which is due to the intrinsic achromatic property of reflective systems.     

Rigorous electromagnetic analysis of the common focusing characteristics of a cylindrical microlens with long focal depth and under multiwavelength illumination

The common focusing characteristics of a cylindrical microlens with a long focal depth and under a given multiple-wavelength illumination are analyzed based on the boundary element method (BEM). The surface-relief profile of a finite-substrate-thickness microlens with a long focal depth is presented. Its focusing performances, such as the common extended focal depth (CEFD), the spot size, and the diffraction efficiency, are numerically studied in the case of TE polarization. The results show that the CEFD of the microlens increases initially, reaches a peak value, and then decreases with increasing preset focal depth. Two modified profiles of a finite-substrate-thickness cylindrical microlens are proposed for enlarging the CEFD. The rigorous numerical results indicate that the modified surface-relief structures of a cylindrical microlens can successfully modulate the optical field distribution to achieve longer CEFD, higher transverse resolution, and higher diffraction efficiency simultaneously, compared with the prototypical microlens. These investigations may provide useful information for the design and application of micro-optical elements in various multiwavelength optical systems.     

Grazing-incidence Monk-Gillieson monochromator based on surface normal rotation of a varied-line-spacing grating

A geometric theory of a grazing-incidence varied-line-spacing plane-grating monochromator system whose scanning is made by a simple grating rotation about the grating normal has been developed for designing Monk-Gillieson monochromators capable of covering an energy range of 0.6-2.5 keV. Analytic expressions are given for the grating equations, focal conditions, dispersion, spectral image shape, and optimization of groove parameters. On the basis of the theory, two monochromator systems have been designed: system I for moderate resolution and system II for relatively high resolution. The validity of the analytic formulas and the expected performance of the designed systems have been evaluated by means of ray tracing. The results show that the analytic formulas are sufficiently accurate for practical applications and that systems I and II would provide resolving power of approximately 1450-600 and 7500-2000, respectively, in the wavelength region of 0.5-2.0 nm.     

Multiple annular linear diffractive axicons

We propose a chromatic analysis of multiple annular linear diffractive axicons. Large aperture axicons are optical devices providing achromatic nondiffracting beams, with an extended depth of focus, when illuminated by a white light source, due to chromatic foci superimposition. Annular apertures introduce chromatic foci separation, and because chromatic aberrations result in focal segment axial shifts, polychromatic imaging properties are partially lost. We investigate here various design parameters that can be used to achieve color splitting, filtering, and combining using these properties. In order to improve the low-power efficiency of a single annular axicon, we suggest a spatial multiplexing of concentric annular axicons with different sizes and periods we call multiple annular aperture diffractive axicons (MALDAs). These are chosen to maintain focal depths while enabling color imaging with sufficient diffraction efficiency. Illustrations are given for binary phase diffractive axicons, considering technical aspects such as grating design wavelength and phase dependence due to the grating thickness.     

Super-resolved spatial light interference microscopy

We report a scheme to achieve resolution beyond the diffraction limit in spatial light interference microscopy (SLIM). By adding a grating to the optical path, the structured illumination technique can be used to improve the resolution by a factor of 2. We show that a direct application of the structured illumination technique, however, has proved to be unsuccessful. Through two crucial modifications, namely, one to the pupil plane of the objective and the other to the demodulation procedure, faithful phase information of the object is recovered and the resolution is improved by a factor of 2.     

Variable Magnification With Kirkpatrick-Baez Optics for Synchrotron X-Ray Microscopy

We describe the distinction between the operation of a short focal length x-ray microscope forming a real image with a laboratory source (convergent illumination) and with a highly collimated intense beam from a synchrotron light source (Köhler illumination). We demonstrate the distinction with a Kirkpatrick-Baez microscope consisting of short focal length multilayer mirrors operating at an energy of 8 keV. In addition to realizing improvements in the resolution of the optics, the synchrotron radiation microscope is not limited to the usual single magnification at a fixed image plane. Higher magnification images are produced by projection in the limit of geometrical optics with a collimated beam. However, in distinction to the common method of placing the sample behind the optical source of a diverging beam, we describe the situation in which the sample is located in the collimated beam before the optical element. The ultimate limits of this magnification result from diffraction by the specimen and are determined by the sample position relative to the focal point of the optic. We present criteria by which the diffraction is minimized.