原子力显微镜测试光学超光滑表面微轮廓的研究

论述了使用原子力显微镜测量超光滑光学表面的优点及其在光学领域中的重要应用。列举了用这种方法测试得到的超光滑光学表面微轮廓图及纳米量级的微缺陷,以及这些表面镀膜前后表面形态结构和微粗糙度的变化。作为比较,列举了用干涉轮廓仪测得相同表面的微粗糙度参数等８。由于原子力显微镜有三维的高精度,而干涉方法只有一维的高精度,所以前者可以得出表面真实形貌和微轮廓。     

高精度表面粗糙度外差干涉仪信号处理系统的研制

针对用于磨床加工的光外差表面粗糙度在线干涉测量仪，文中介绍了整机的信号处理系统，着重讨论了两项关键技术。即宽动态范围测量信号的自动控制和高精度动态相位测量，系统的测量精度达２．６°（相当于３．２ｎｍ），允许测量中最大多普勒频移±２０ｋＨｚ（对应高度的变化率±８．７５×１０－３ｍ／ｓ），完全满足磨床加工中表面粗糙度在线测量的要求。现场测试证实了这一点，这对于精加工、超精加工表面粗糙度的在线质量控制、提高加工精度等非常重要。     

温度和应变对光纤折射率的影响

采用迈克尔逊（Ｍｉｃｈｅｌｓｏｎ）光纤白光干涉系统，通过测量随着温度或应变改变而变化的光程，给出了单模光纤有效折射率的温度和应变相关特性。对于ＳＭＦ－２８型单模光纤，测得折射率温度系数和应变温度系数在波长为１３００ｎｍ处分别为０．７６２×１０－５／℃及－０．１３３２×１０－６／με；在波长１５５０ｎｍ处则为０．８１１×１０－５／℃及－０．１６４９×１０－６／με。并与几种不同光纤相应的数据进行了比较。     

光学轮廓仪对光学元件表面空间波长回应的研究

在分析光学轮廓仪的空间分辨率和带限功率谱密度函数的基础上，用新测不同要品的大量数据研究了光学元件表面粗糙度测量与光学轮廓仪对表面空间波长的带限顺应关系，对由光学轮廓仪不同带宽限制内测量元件表面粗糙度不同回应所引起的不同偏差的解决办法提出了几点建议。     

“天光”一号MOPA系统光学元件加工与镀膜的进展

本文阐述了在中国原子能科学研究院“天光一号”ＫｒＦ激光核聚变实验装置上，ＭＯＰＡ系统光学元件加工与镀膜研究工作的进展。实验测量结果表明，加工后的基片表面均方根粗糙度对于Ｋ９光学玻璃与熔融石英玻璃来说分别为σｒｍｓ＝１．８±０．５ｎｍ，σｒｍｓ＝２．０±０．４ｎｍ。镀ＨｆＯ２／ＳｉＯ２高反射膜的光学元件的反射率与破坏阈值分别为Ｒ＞９９．５％，Ｅｔｈ＝１．３０～１．３３Ｊ／ｃｍ２。镀Ａｌ２Ｏ３／ＭｇＦ２增透膜的光学元件的透射率与破坏阈值分别为Ｔ＞９９．５％，Ｅｔｈ＝１．３～１．９７Ｊ／ｃｍ２。     

软X射线超光滑表面传输特性的初步研究

本文给出了软Ｘ射线超光滑表面散射的一级近似的一般理论推导，从中给出软Ｘ射线的散射传输特性。通过实验测量了λ＝２４．３ｎｍ、２５．６ｎｍ时具有超光滑表面的Ｍｏ、Ｓｉ样品的反射率和λ＝４．４６ｎｍ时熔石英超光滑样品的反射单。对４．４６ｎｍ进行了了散射测量，可以明显观察到软Ｘ射线的非正常反射现象。     

粲夸克偶素P波态χ_（c0）宽度测量

利用北京谱仪在北京正负电子对撞机上采集的３５０万（２Ｓ）事例，通过（２Ｓ）→γπ－和γＫ＋Ｋ－反应道测量了Ｘｃ０的总宽度．由ＭｏｎｔｅＣａｒｌｏ模拟给出的质量分辨函数，利用拟合Ｘｃ２谱形得到的质量分辨作标定后，用于Ｘｃ０宽度的拟合，得到Ｘｃ０的宽度为（１５．０）ＭｅＶ．同时定出了ＸｃＪ（Ｊ＝０，２）到π＋π＝和Ｋ＋Ｋ－的衰变分支比．结果为Ｂ（Ｘｃ０→π＋π－）＝（４．２７±０．２３±Ｏ．６０）×１０－３；Ｂ（Ｘｃ０→Ｋ＋Ｋ－）＝（３．４４±０．２１±０．４７×１０－３；Ｂ（Ｘｃ２→π＋π－）＝（１．５２±０．１７±０．２９）×１０－３和Ｂ（Ｘｃ２→Ｋ＋Ｋ－）＝（５．２±１．１±１．８）×１０－４，其中第一项误差为统计误差，第二项为系统误差。     

在线测量表面粗糙度的共光路激光外差干涉仪

一种新型的、用于在线测量表面粗糙度的激光外差干涉仪已研制完成。该仪器体积小（２５ｃｍ×２０ｃｍ×１０ｃｍ）、抗外界环境干扰能力强。仪器以稳频半导体激光器作为光源。共光路设计,使测量光和参考光沿同一路径入射到被测表面上。计大数和测小数周期相结合的外差信号处理方法,实现了大的动态测量范围和很高的测量分辩率。同时还采用了全反射临界角法进行自动聚焦。该仪器的纵向和横向分辨率分别为０．３９ｎｍ和０．７３μｍ;自动聚焦范围为±０．５ｍｍ,在焦点±２５μｍ范围内,聚焦精度为１μｍ;８０分钟内整机稳定性：３σ＝１．９５ｎｍ。     

新间接紫外光度法测定微量SO3^2—

在ｐＨ７．０混合磷酸盐介质中,ＳＯ３＾２－使Ｉ３＾－与ＣＴＭＡＢ生成离子缔合物ＣＴＭＡ＾＋,Ｉ３＾－而褪色,从而建立了测定ＳＯ３＾２－的新间接紫外光度法,测定波长为３６５ｎｍ,ＳＯ３＾２－浓度在０－２５μｇ／２５ｍＬ内服从比耳定律,表观摩耳吸光系数为ε＝６．０４×１０＾４Ｌ·ｍｏｌ＾－１·ｃｍ＾－１,可用于食品中微量ＳＯ３＾２－的测定,其结果满意。     

用于等离子体电位测量的电容探针和发射探针

本文给出了发射探针和电容探针测量等离子体电位的实验和方法。发射探针采用直流功率加热，并在较强电子发射条件下运行（Ｉ_（ｅ０）／Ｉ_（ｅ０）＞１）。电容探针表面二次电子发射系数δ≥１。本文对发射探针的电子发射性能、工作电流、电容探针的输入、输出电压关系进行了标定实验。得到了电容探针的校准系数分别为３×１０（－３）、５×１０（－４）。实验给出了ＭＭ－４会切中心等离子体电位Ｖ_（ｐ４）＝－８２±９－１２２±１２Ｖ；ＭＭ－４Ｕ东、西会切中心等离子体电位分别为Ｖ_（Ｐ４ｕ１）＝－５２．９±３．２Ｖ，Ｖ_（Ｐ４ｕ２）＝－６２±３．２Ｖ。     

碳化硅表面硅改性层的磁介质辅助抛光

为了实现碳化硅表面硅改性层的精密抛光,获得高质量光学表面,对磁介质辅助抛光技术进行研究。设计了适合碳化硅表面硅改性层抛光的磁介质辅助抛光工具,并对抛光工具的材料去除函数进行研究。针对材料去除函数的特性,对数控磁介质辅助抛光的驻留时间算法进行了研究。采用磁介质辅助抛光技术对碳化硅表面硅改性层平面样片进行了抛光实验。经过一次抛光迭代,碳化硅样片表面硅改性层的面形精度(均方根)由0.049λ收敛到0.015λ（λ=0.6328 μm）,表面粗糙度从2 nm改善至0.64 nm。实验结果表明基于矩阵代数的驻留时间算法有效,磁介质辅助抛光适合碳化硅表面硅改性层加工。     

Surface disorder in c-Si induced by swift heavy ions

The disorders induced in crystalline silicon (c-Si) through the process of electronic energy loss in the swift heavy ion irradiation were investigated. A number of silicon <1 0 0> samples were irradiated with 65 MeV oxygen ions at different fluences, 1×10¹³ to 1.5×10¹⁴ ions/cm², and characterized by the Raman spectroscopy, the optical reflectivity, the X-ray reflectivity, the atomic force microscopy (AFM) and the X-ray diffraction (XRD) techniques. The intensity, redshift, phonon coherence length and asymmetric broadening associated with the Raman peaks reveal that stressed and disordered lattice zones are produced in the surface region of the irradiated silicon. The average crystallite size, obtained by analyzing Raman spectrum with the phonon confinement model, was very large in the virgin silicon but decreased to<100 nm dimension in the ion irradiated silicon. The results of the X-ray reflectivity, AFM and optical reflectivity of 200–700 nm radiation indicate that the roughness of the silicon surface has enhanced substantially after ion irradiation. The diffusion of oxygen in silicon surface during ion irradiation is evident from the oscillation in the X-ray reflectivity spectrum and the sharp decrease in the reflectivity of 200–400 nm radiation. The rise in temperature, estimated from the heat spike model, was high enough to melt the local silicon surface. The results of XRD indicate that lattice defects have been induced and a new plane <2 1 1> has been formed in the silicon <1 0 0>after ion irradiation. The results of the present study show that the energy deposited in crystalline silicon through the process of electronic energy loss ～0.944 keV/nm per ion is sufficient to induce disorders of appreciable magnitude in the silicon surface even at a fluence of ～10¹³ ions/cm².     

Ultra-smooth polishing of high-precision optical surface

A new method of ultra-smooth uniform polishing was presented, which can avoid high-precision surface figure getting worse after ultra-smooth polishing. At first, the fundamental and process were introduced. Then the process was simulated with “Gauss” and “V” type removal function. It shows that there will be no significant influence on optical surface figure after ultra-smooth uniform polishing with any type removal function. To demonstrate the process, a high-precision Ø100 mm fused silica flat optical element was polished, which was prior figured by IBF. Its surface figure accuracy root-mean-square (rms) value is improved from initial 3.624 nm to final 3.393 nm, the mid-spatial frequency surface roughness rms value is improved from initial 0.477 nm to final 0.309 nm, and the high-spatial frequency surface roughness rms value is improved from initial 0.167 nm to final 0.0802 nm. At last, the surface quality of the lens was analyzed by power spectral density (PSD). The result indicates that the surface roughness of high-precision optical element could be improved by ultra-smooth uniform polishing method without the surface figure destroyed.     

Effect of Density and Surface Roughness on Optical Properties of Silicon Carbide Optical Components

The effect of density and surface roughness on the optical properties of silicon carbide optical components is investigated. The density is the major factor of the total reflectance while the surface roughness is the major factor of the diffuse reflectance. The specular reflectance of silicon carbide optical components can be improved by increasing the density and decreasing the surface roughness, in the form of reducing bulk absorption and surface-related scattering, respectively. The contribution of the surface roughness to the specular reflectance is much greater than that of the density. When the rms surface roughness decreases to 2.228nm, the specular reflectance decreases to less than 0. 7% accordingly.     

Mirau相移干涉法测量微透镜阵列面形

基于Mirau相移干涉法，在实验室环境下对微透镜阵列的微表面形貌进行了轮廓测量.实验使用He-Ne激光器作为光源，干涉成像系统由Mirau干涉物镜和其他光学元件组成.在实验中使用压电陶瓷执行器作为相移器，通过5步相移法计算待测表面形貌.实验结果表明，基于Mirau相移干涉法对微透镜阵列面形的测量，水平分辨率达到1.1 μm，垂直测量准确度达到6.33 nm，垂直测量范围为5 μm.对于微透镜阵列的面形测量，通过将微透镜阵列划分为若干微小区域以保证局部面形最大高度小于5 μm，然后辅以精密平移机构进行若干次5步相移法测量局部面形，再利用相位重建所得的数据进行拼接和3D轮廓重建，最终得到整个微透镜阵列的精确微表面形貌.     

Influence of Cr<Superscript>+</Superscript> ion implantation and pulsed ion-beam annealing on the formation and optical properties of Si/CrSi<Subscript>2</Subscript>/Si(111) heterostructures

The effect of pulsed ion-beam annealing on the surface morphology, structure, and composition of single-crystal Si(111) wafers implanted by chromium ions with a dose varying from 6 × 10¹⁵ to 6 × 10¹⁶ cm⁻² and on subsequent growth of silicon is investigated for the first time. It is found that pulsed ion-beam annealing causes chromium atom redistribution in the surface layer of the silicon and precipitation of the polycrystalline chromium disilicide (CrSi₂) phase. It is shown that the ultrahigh-vacuum cleaning of the silicon wafers at 850°C upon implantation and pulsed ion-beam annealing provides an atomically clean surface with a developed relief. The growth of silicon by molecular beam epitaxy generates oriented 3D silicon islands, which coalesce at a layer thickness of 100 nm and an implantation dose of 10¹⁶ cm⁻². At higher implantation doses, the silicon layer grows polycrystalline. As follows from Raman scattering data and optical reflectance spectroscopy data, semiconducting CrSi₂ precipitates arise inside the silicon substrate, which diffuse toward its surface during growth.     

共光路外差干涉法精密测量光学表面

报道了光学外差法测量表面起伏精度及横向分辨精度达到０．１１ｎｍ及４μｍ。本文采用的是完全共光路外差干涉系统，阐述了它的原理、构造及噪声的影响，并将测量结果与其它商品仪器测量结果作了比较。     

13.9 nm马赫贞德干涉仪用软X射线分束镜研究

 介绍了13.9 nm马赫贞德干涉仪用软X射线分束镜的设计、制备与性能检测。基于分束镜反射率和透过率乘积最大的评价标准，设计了13.9 nm软X射线激光干涉实验用多层膜分束镜。采用磁控溅射方法在有效面积为10 mm×10 mm、厚度为100 nm的Si3N4基底上镀制了Mo/Si多层膜，制成了多层膜分束镜。利用X射线掠入射衍射的方法测量了Mo/Si多层膜的周期。用扩束He-Ne激光束进行的投影成像方法定性分析了分束镜的面形精度，利用光学轮廓仪完成了分束镜面形精确测量。利用北京同步辐射装置测量了分束镜反射率和透射率，在13.9 nm处，分束镜反射率和透过率乘积达4%。使用多层膜分束镜构建了软X射线马赫贞德干涉仪，并应用于13.9 nm软X射线激光干涉实验中，获得了清晰的含有C8H8等离子体电子密度信息的动态干涉条纹。     

5 × 10 Gbps WDM-CAP-PON based on frequency comb using OFDM with blue LD

Presently, optical access networks are in great demand to meet the bandwidth requirement due to rapid growth in high speed applications for smart devices, cloud computing, big data analysis and other 5G applications. In this paper, 5?×?10 Gb/s wavelength division multiplexing carrier-less amplitude phase modulation-passive optical network (WDM-CAP-PON) with frequency comb is proposed and demonstrated. Also, 450 nm blue laser diode having bandwidth 0.8 GHz is used for visible light communication using 6 m FSO link to support cost effective high data rate optical network. The WDM-CAP-PON employing orthogonal frequency division multiplexing has been analysed in terms of tolerance to the fiber non-linearities through the effect of variations in launch power (??5 to 4 dBm), datarate (2.5–40 Gb/s) and distance (20–110 km) on Q-factor and error vector magnitude (EVM%) by considering pre-, post- and symmetrical-dispersion compensation schemes. It is reported that post-compensation is superior to pre- and symmetrical-compensation schemes to achieve the minimum 3.8?×?10^?3 BER under 7% forward error correction (FEC). The faithful transmission distance achieved for 10 Gb/s WDM-CAP-PON using post dispersion compensation scheme is 110 km.