Low-threshold laser oscillation due to group-velocity anomaly peculiar to two- and three-dimensional photonic crystals

An analytical expression of the lasing threshold for arbitrary photonic cry stals was derived, which showed their reduction due to small group velociti es of electromagnetic eigenmodes. The lasing threshold was also evaluated n umerically for a two-dimensional photonic crystal by examining the divergen ce of its transmission and reflection coefficients numerically. A large red uction of lasing threshold caused by a group-velocity anomaly that is pecul iar to two- and three-dimensional photonic crystals was found. (C) 1999 Opt ical Society of America.