Very low threshold photonic band edge lasers from free-standing triangular photonic crystal slabs

Summary form only given. Recently, two-dimensional photonic crystal lasers without defect cavities have drawn much attention. The operation of theses lasers is based on the enhancement of optical density of states at photonic band edges. Since the refractive index variations of the reported lasers are very small, typically on the order of 0.1, the device size has been larger than (100 /spl mu/m). Here we report photonic band edge lasers formed in a free-standing photonic crystal slab. The effective refractive index variation in the triangular array of air hole patterns is larger than expected. Therefore, large enhancement of photon density of states at band edges is expected.