A combination of advanced silicon-processing techniques was used to create three-dimensional (3D) photonic crystals with a 180-nm minimum feature size. The resulting 3D crystal displayed a strong stop band at optical wavelengths from λ=1.35 μm to λ=1.95 μm . This is believed to be the smallest 3D crystal with a complete 3D photonic bandgap ever created.
© 1999 Optical Society of America
J. G. Fleming and Shawn-Yu Lin, "Three-dimensional photonic crystal with a stop band from 1.35 to 1.95 μm," Opt. Lett. 24, 49-51 (1999)