Abstract
We describe here recent progresses in two types of photonic crystal lasers, which can miniaturize
conventional semiconductor lasers significantly. One is Si Raman laser based on ultrahigh-Q
nanocavities, where we discuss the importance of the difference between Raman frequency and the
frequency spacing of two-nanocavity modes and the effect of strain which exists in Si slab. The other is
high-beam quality, high power laser based on band-edge effect of photonic crystals, where we investigate
the distribution of resonant frequency of individual small areas inside the device and mutual injection
locking phenomena among the neighboring small areas.
