A single mode high power vertical cavity surface emitting laser (VCSEL) using photonic crystals. A photonic crystal is included in at least one mirror layer of a VCSEL. The reflectivity of the photonic crystal is dependent on the wavelength and incident angle of the photons. The photonic crystal can be formed such that the VCSEL lases at a single mode. Because a single mode is generated, the aperture of the VCSEL can be enlarged to increase the power that is generated by the VCSEL for that mode. The photonic crystal can be used with or without DBR layers. The photonic crystal, in one example, forms an external cavity.