Guided-mode resonant Brewster filter consisting of two homogenous layers and a single grating with an equal refractive index  

作　　者：麻健勇 范永涛 

机构地区：[1]Shanghai Institute of Fine Mechanics and Optics,Chinese Academy of Sciences

出　　处：《Chinese Physics B》2012年第3期453-457,共5页中国物理B（英文版）

基　　金：Project supported by the Natural Science Foundation of Shanghai Committee of Science and Technology,China (Grant No. 10ZR1433500)

摘　　要：In this paper, a new type of resonant Brewster filter （RBF） consisting of two homogenous layers and a single grating with an equal refractive index is presented. The properties are studied by using the plane waveguide method （PWM） and rigorous coupled-wave analysis （RCWA）. It is found that the variation of the grating thickness does not effectively change the position of the resonant wavelength, however it has a remarkable effect on the line width, and the resonant peak can be adjusted back to its original position by slightly tuning the grating period. Moreover, by simultaneously tuning the thicknesses of the homogeneous layers above and beneath the grating structure, multiple channels can also be obtained when the RBF is illuminated at the Brewster angle calculated with the effective medium theory （EMT） of subwavelength grating. The adjacent optical thickness for acquiring the multiple channels is about three-quarters of the resonant wavelength. Furthermore, it is demonstrated that the line width at the operating resonant wavelength can be appreciably narrowed by tuning the thickness of the homogenous layer to its corresponding thickness without fine tuning the grating period or the thickness. Therefore, it is very useful for designing filters with different line widths at the desired wavelength. In addition, it is shown from our calculations that the symmetrical line feather can be obtained if the total optical thickness for the homogeneous layer meets the special condition.In this paper, a new type of resonant Brewster filter （RBF） consisting of two homogenous layers and a single grating with an equal refractive index is presented. The properties are studied by using the plane waveguide method （PWM） and rigorous coupled-wave analysis （RCWA）. It is found that the variation of the grating thickness does not effectively change the position of the resonant wavelength, however it has a remarkable effect on the line width, and the resonant peak can be adjusted back to its original position by slightly tuning the grating period. Moreover, by simultaneously tuning the thicknesses of the homogeneous layers above and beneath the grating structure, multiple channels can also be obtained when the RBF is illuminated at the Brewster angle calculated with the effective medium theory （EMT） of subwavelength grating. The adjacent optical thickness for acquiring the multiple channels is about three-quarters of the resonant wavelength. Furthermore, it is demonstrated that the line width at the operating resonant wavelength can be appreciably narrowed by tuning the thickness of the homogenous layer to its corresponding thickness without fine tuning the grating period or the thickness. Therefore, it is very useful for designing filters with different line widths at the desired wavelength. In addition, it is shown from our calculations that the symmetrical line feather can be obtained if the total optical thickness for the homogeneous layer meets the special condition.

关 键 词：guided mode resonance Brewster effect plane waveguide method 

分 类 号：TN252[电子电信—物理电子学]