Photonic Crystal Possibilities
	Light can be guided around sharp (less than l) corners by defects in photonic crystals in theory1 and in practice2 (1.55 mm)
				Only a few periods of the crystal are necessary for isolation, so it should be possible to create an optical switch with small programmable defects
		1. J.D. Joannopoulos, R.D. Meade, J.N. Winn, Photonic Crystals (Princeton University Press, New York, 1995) 2. Lin S-Y, Chow E, Johnson SG, Joannopoulos JD, “Demonstration of highly efficient waveguiding in a    photonic crystal slab at the 1.5-µm wavelength,” Optics Letters, vol. 25, no. 17, (2000)