Patent ID: 7639718
Filing Date: 2009-12-29
Classification: H01S

Abstract:
1. An apparatus for generating a second harmonic beam via intra-cavity frequency doubling, the apparatus comprising: a laser diode having a back facet, forming one end of the optical cavity, a front facet, a gain medium between the back and front facet wherein first light is generated, the first light having a fundamental wavelength and spectral bandwidth; a reflective, non dispersive, volume holographic grating forming the other end of the laser cavity, the volume holographic grating having a front facet facing the laser cavity comprising an anti-reflection coating for the first fundamental light and a high reflection coating for the second harmonic light, the normal to the front facet of the volume holographic grating making an angle approximately 45 degrees with respect to the direction of the first fundamental light; a non-linear second harmonic crystal positioned between the laser diode and the reflective volume holographic element generating the second harmonic light; Wherein the volume holographic element receives first fundamental light and diffracts the first fundamental light back to the laser diode, the diffracted light having a narrower bandwidth than the fundamental light and a center wavelength given by the center wavelength of the reflective volume holographic grating; Wherein the volume holographic element has the front facet that reflects the second harmonic light.