【作者】 王琦；

【导师】 庄松林；

【作者基本信息】 上海理工大学 ， 光学工程， 2012， 博士

【摘要】 导模共振亚波长滤光器件因为具有极窄的带宽、极高的衍射效率和结构简单等优点，近年来受到了人们广泛的关注。利用导模共振效应，可以设计出性能卓越的光学滤波器，偏振分离器等光学器件，促进光通信以及相关光学领域的发展。本论文利用亚波长光栅导模共振效应，对具备滤光和高反特性的导模共振亚波长滤光器件从理论设计、实验制备以及应用三个方面进行了研究，基于全息工艺制备了共振波长在693nm的可见光波段的导模共振滤光器件，设计了几种可调谐导模共振滤光器件，并分析讨论了导模共振器件的应用前景。本文首先介绍了严格的矢量衍射理论，并阐述了利用耦合波方法分析处理不同偏振入射时的矩形槽光栅的衍射问题的一般过程。基于亚波长光栅结构的导模共振异常现象，分析了不同的结构参数对导模共振滤光器件光学特性的影响，通过调节这些结构参数可以设计出具有理想滤光特性曲线的导模共振滤光器件的结构。研究了光栅结构之下的薄膜层对亚波长光栅导模共振滤光器件的光谱特性的调控现象，并利用这种调控作用进行了两种创新方法和技术的研究：（1）在设计亚波长导模共振滤光器件的结构方面，通过调整光栅层结构之下的薄膜层厚度来达到不改变导模共振滤光片的光学特性的前提下减小光栅层槽深的设计要求，可以解决所设计光栅槽深过深带来制备工艺的困难，从而达到降低导模共振滤光片的制备难度的目的；（2）在制备亚波长导模共振滤光器件方面，分析了亚波长光栅结构的双层导模共振滤光片制备过程中由于对光栅层的过刻蚀现象造成的制备误差从而导致导模共振滤光片光谱漂移的现象。提出了通过对制备后期的滤光片镀上一定厚度和折射率的薄膜层可以修正由于周期和光栅槽深的制备误差而引起的光谱漂移现象，从而降低了亚波长导模共振滤光片对光栅周期和槽深制备精度的要求，降低了导模共振滤光片结构的制备难度，提高了样品制备的成品率。针对导模共振光学元件在光通信、防伪以及可调谐激光器等领域的应用，基于严格的耦合波理论，研究了几种具有窄带高反射功能的可调谐导模共振滤光器件。介绍了利用方位角对导模共振滤光片的控制作用，提出了利用方位角的变化实现可调谐导模共振滤光片结构的设计方法。结合聚合物分散液晶的电光特性设计了电控聚合物分散液晶折射率的可调谐导模共振滤光器件，实现了共振波长从672.4nm变化到698.4nm，可调谐共振波长最大调谐范围可达到26nm。此外，首次提出了光谱能量调谐导模共振滤光器件的概念及其设计方法，通过特定结构及利用方位角的改变可以实现导模共振的光谱能量在两个特定波长通道的调谐，这在光生物学精确定量的研究方面有着潜在的应用价值。提出利用导模共振光栅阵列再现彩色图像，通过结构相同仅周期不同微结构将光分解成所需要的红、绿、蓝三色光充当三基色，以此表现图像，改变了传统的用彩色油墨实现图像的色彩的概念。由于导模共振光栅微结构的结构简单，高衍射效率和窄带的性质，易得到高纯度的单色光，对微结构进行排列分布处理即可得到彩色图像。初步仿真结果表明在TE偏振光入射下已能够较真实的还原原图像。这种彩色图像再现的方法节省资源、环保，还可以实现普通油墨无法印刷的光变效果，在印刷、真迹保存，光显示等行业具有巨大的潜在应用价值。根据严格的耦合波理论和导模共振滤光片的设计方法设计了2-18GHz微波波段的导模共振超材料结构，该材料在9.7GHz波段截止透射，在除此截止带之外的整个2-18GHz波段透射率超过90%。此外，利用氧化铪和氧化钽两种不同折射率材料设计了具有相同共振波长的双层亚波长导模共振滤光片的结构，基于亚波长全息光栅掩模制备理论及工艺基础研究了亚波长导模共振滤光片的制备流程和工艺，制备了共振波长为693nm的亚波长导模共振滤光片，对所制备的导模共振滤光片的滤光特性进行了测试并进行了误差分析。更多还原

【Abstract】 Guided-mode resonance (GMR) filter is of great interest recently for itsoutstanding advantages such as narrowband of few nanometers, high efficiency, lowsidebands extended over a large spectral range, simple structures and so on. Opticaldevices such as of optical filters, polarization separators with superior performancescan be designed utilizing the guided-mode resonance effect, which can advance thedevelopment of optical communications and related optical areas. The design andexperimental result of GMR filters with the characteristics of filter and highreflectance are presented in this dissertation.Visible band guided-mode resonancefilter with the resonance wavelength at693nm is fabriciated which is based onholographic technique. Moreover, kinds of tunable guided-mode resonace filter arepresented. And the application prospect of guided-mode resonace filter is alsodiscussed.In this dissertation, the rigorous diffractive theory is presented firstly. A generaldiffraction analysis of rectangular grating with different polarizations is introducedby the method of the rigorous coupled-wave ananlysis (RCWA). Based on theresonance anomalous phenomenon occurred in the subwavelength waveguide grating,the effects on the filter characteristics with different structure parameters wasanalyzed which shows that the GMR filter with ideal filter characteristics can bedesigned by adjusting those parameters. It could be found that the thin-film layerunder the grating layer can be used to control the spectrum response curve of thedouble layer GMR filter with RCWA.The contoral could be used to reduce thefabraction difficulties at least in two aspects. First, we can adjust the thickness of thethin-film layer under the grating layer to decrease the depth of the grating groovewithout changing the filter characteristics during the design process. In this way, thefabraction difficulty which is arised by the deep groove grating can be solved.Furthermore, the deviation caused by overetching during the fabrication process willlead to the deviation of the resonant wavelength. To compensate this deviating, theway of covering one compensatory layer film with certain thickness and refractiveindex on the surface of the GMR filter is investigated. Simulation results show thatthe deviation is compensated perfectly by this way, which means that it can be usedto reduce requirements of precision to the grating period and the groove depth bycontrolling the thin-film layer under the grating laye during the fabrication process. As the applications of GMR devices in optical communications, security, tunablelaser and so on are widely concerned, several kinds of the tunable GMR filters withnarrow-bands and high-reflectances were presented based on the rigorouscoupled-wave theory. With the analysis of the variation azimuthal angles influence tothe GMR flter, a kind of tunable narrow band GMR filter designed by tuning theazimuthal angles is illustrated. Combined the electro-optical property of polymerdispersed liquid crystal (PDLC) with the GMR property, a kind of tunable GMRfilter based on PDLC is designed by electronically controlling the refractive index ofPDLC. The resonance wavelength can be tuned from672.4nm to698.4nm, whichachieved a tunable wavelength range of up to26nm. In addition, the concept anddesign of the spectrum energy tunable GMR filter is put forward for the first time.With a specific structure of GMR filter, the energy of the reflectance spectrum can betuned in the dual channels by tuning the azimuthal angles.The spectrum energytunable GMR filter can accurate control the energy of the reflectance spectrum whichmay have potential application in the biologica area. The paper utilizes the array toproduce colored images that changes the traditional color ink colored image concept.Those guided mode resonant gratings are fabricated with the same structure butdifferent period to filter light into the needed for red, green and blue that served asthe three primary colors to display images. Because of the excellent characteristics ofguided mode resonant grating such as simple structure, high diffraction efficiencyand narrowband, monochromatic light of the three primary colors with high puritycan be easily achieved. Colored image can be obtained by arranged and distributedthose microstructure gratings. Preliminary simulation results show that the originalimage can be reproduced realistic with the TE polarized incident light. Owing withthe advantages of resources saving, environmental protection,the method of coloredimage reproduction has the potential for industrial production and application inmany fields,such as the printing industry、authentic preservation and light display.GMR metamaterial structure with the resonance occuring during2and18GHzin the microwave band was given according to the RCWA and design method ofGMR filter. The transmission cut off in the9.7GHz, while the transmission farawayfrom the cut-off zone exceeding90%over the2and18GHz. In addition, thestructures of the double layer subwavelength GMR filter with the resonancesoccurring in the same resonance wavelength were designed by using different refractive index material of HfO2and Ta2O5. The fabrication processe andtechnology of the subwavelength visible band GMR filter with the resonancewavelngthe at693nm were investigated based on the fabrication process of thesubwavelength grating. The filter characteristics of the GMR filter was tested anderror analysis.更多还原