摘要 |
PROBLEM TO BE SOLVED: To provide a photonic crystal laser in which a threshold required for laser oscillation can be lowered sufficiently, by reducing the intensity of light emitted in a direction perpendicular to a photonic crystal as compared with prior art.SOLUTION: In a photonic crystal laser having an active layer 103, and a photonic crystal layer and oscillating with a wavelength λ, the photonic crystal layer comprises: a first photonic crystal layer 111 provided on the side close to the active layer; and a second photonic crystal layer 112 provided on the side farther from the active layer than the first photonic crystal layer. An optical thickness defined by the product of the actual thickness of a photonic crystal layer and the effective refractive index of waveguide mode formed by the photonic crystal layer is equal to the wavelength λ. Average refractive index of the second photonic crystal layer is higher than that of the first photonic crystal layer, and the thickness of the second photonic crystal layer is set to one half or more of the thickness of the first photonic crystal layer. |