Mid-infrared doping tunable transmission through subwavelength metal hole arrays on InSb.

Doping-tunable mid-infrared extraordinary transmission is demonstrated from a periodic metal hole array patterned on n-InSb. The polarization-dependent transmission was measured at room temperature and 77 K. In addition, the extraordinary transmission was measured for incident angles from 0 degrees to 35 degrees in 5 degrees steps. A fundamental resonance shift of approximately 123 cm-1 (1.4 microm) is observed by varying the doping from 1 x 10(16) to 2 x 10(18) cm(-3). The calculated transmission resonances were in good agreement with the experimental results. This suggests that InSb semiconductor-based plasmonic structures may be suitable for a variety of tunable mid-infrared device applications.