Efficient dielectric metasurface collimating lenses for mid-infrared quantum cascade lasers
Efficient dielectric metasurface collimating lenses for mid-infrared quantum cascade lasers
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DOI：
10.1364/oe.23.033310
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发表时间：
2015-12-28
期刊：
影响因子：
3.8
通讯作者：
Faraon, Andrei
中科院分区：
文献类型：
--
作者：
Arbabi, Amir;Briggs, Ryan M.;Faraon, Andrei
单模半导体激光器发出的光一般具有较大的发散角，光束准直需要大的数值孔径透镜。可见光和近红外激光是使用非球面玻璃或塑料透镜准直的，但中红外量子级联激光器的准直通常需要更昂贵的非球面透镜，这些非球面透镜由锗、硫化物或其他红外透明材料制成。在这里，我们报道了有效准直单模量子级联激光器输出光束的中红外介电准平面透镜。这种亚表面透镜由平面蓝宝石衬底上的非晶硅柱组成，可以使用传统的单步紫外二进制光刻以低成本制造。利用数值孔径为0.86、传输效率为79%的偏振不敏感准表面透镜，准直了4.8mm分布反馈量子级联激光器的中红外辐射。准直光束的半发散角为0.36度，光束质量因子M-2=1.02。(C)2015年美国光学学会
Light emitted from single-mode semiconductor lasers generally has large divergence angles, and high numerical aperture lenses are required for beam collimation. Visible and near infrared lasers are collimated using aspheric glass or plastic lenses, yet collimation of mid-infrared quantum cascade lasers typically requires more costly aspheric lenses made of germanium, chalcogenide compounds, or other infrared-transparent materials. Here we report mid-infrared dielectric metasurface flat lenses that efficiently collimate the output beam of single-mode quantum cascade lasers. The metasurface lenses are composed of amorphous silicon posts on a flat sapphire substrate and can be fabricated at low cost using a single step conventional UV binary lithography. Mid-infrared radiation from a 4.8 m m distributed-feedback quantum cascade laser is collimated using a polarization insensitive metasurface lens with 0.86 numerical aperture and 79% transmission efficiency. The collimated beam has a half divergence angle of 0.36 degrees and beam quality factor of M-2 = 1.02. (C) 2015 Optical Society of America