A surface plasmonic coupled mid-long-infrared two-color quantum cascade detector

A novel mid-long-infrared two-color photodetector is proposed. It combines quantum cascade detector (QCD) and surface plasmonic coupling structure. The reflection spectrum and electric field are analyzed by algorithm of finite difference time domain method (FDTD). This QCD is sensitive to 4.4 μm and 9.0 μm infrared light. Mid-infrared and long-infrared pixels are interlaced arranged with specific plasmonic micro-cavity structures integrated. 7.1 and 7 times enhancement in optical absorption are obtained for mid-infrared and long-infrared pixels, respectively. Besides, a polarization-discriminating detection performance has been observed.