High focusing grating reflectors with TE-polarized normal incidence

• 作 者: 马婷 袁晓东 叶卫民 徐威 秦石乔 朱志宏
• 机 构: College of Optoelectronic Science and Engineering,National University of Defense Technology,State Ke
• 出 处: Chinese Optics Letters
• 发表日期: 2014年02期
• 关键词: grating focusing polarized fairly reflectance reflector incidence reflective dep

We design two types of reflectors by using subwavelength high-index contrast gratings,which exhibit similar high focusing capabilities at normal incidence with a TE-polarized plane wave.One type has bars of different heights,whereas the other has bars of different depths.Both grating reflectors are designed to be approximately 22 μm in structural length and 10 μm in focal length,at an operating wavelength of 1.55 μm.Both achieve a full-width-half-maximum of 0.9 μm at the focal plane,which is fairly close to the diffraction limit.Their reflectance reach as high as 94% and 91%.

We design two types of reflectors by using subwavelength high-index contrast gratings, which show similar high focusing capabilities at normal incidence with a TE-polarized plane wave. One type has bars of different heights, and the other has bars of different depths.Both The grating reflectors are designed to be approximately 22 μm in structural length and 10 μm in focal length, at an operating wavelength of 1.55 μm. Both achieve a full-width-half-maximum of 0.9 μm at the focal plane, which is fairly close to the diffraction limit.Their reflectance reach as high as 94% and 91%.