The disclosed invention is an external cavity laser with a volume
holographic VHG output coupler. The facet of the VHG is coated with a
very high reflectivity coating (HR close to 100%) for the purpose of
reflecting the second harmonic (SH) light generated intra-cavity. The HR
coating for the SH light has also an anti-reflection (AR) coating at the
fundamental wavelength. The reflected second harmonic (SH) light is
either reflected directly out of the cavity by the VHG or back to the
cavity towards the optics that deflect the SH light out of the cavity.