We demonstrate a photopumped photonic crystal laser based on synthetic opal
single crystal infiltrated with various laser dye solutions. The optical f
eedback in these lasers is provided via Bragg scattering of light from crys
tallographic planes in the opal. Localization of the laser modes within the
stop band is assigned to defect states caused by crystal structure faults.
We distinguish this photonic lasing mechanism from another regime of stimu
lated emission associated with random lasing what could be also observed in
dye-infiltrated opals, but at higher excitation intensities. (C) 2001 Else
vier Science B.V. All rights reserved.