Nanoscale Lasers Based on Carbon Peapods
  A scheme of nanoscale lasers based on the so-called carbon peapods is examined in details. Since there is considerable cylindrical empty space in the middle of a single-wall carbon nanotube (SWCNT), it can serve as a laser resonant cavity that consists of two highly reflecting, alignment &#8220;mirrors&#8221; separated by some distance. These mirrors refer to the ordered arrays of C60 inside SWCNTs, which have photonic bandgap structures. Meanwhile, ideally single-mode lasers are supposed to be produced in the nanoscale resonant cavity. 
S. He, J.Q. Shen, Haiyang Li, Hongnian Li