Abstract: This invention is a broadband intra cavity laser mode convertor. This is a hologram of a complex phase mask imprinted inside of a volume Bragg grating with wide spectral width recorded in photo-thermo-refractive (PTR) glass. This hologram is a broadband phase converting monolithic device capable of use over a broad wavelength range at high instant and average power because of low absorption coefficient and low nonlinear refractive index of PTR glass. Therefore, it can be used for broadband optical beam transformations and conversion of modes in laser resonators.

Abstract: A spectral beam combiner includes at least one transmitting volume chirped Bragg grating (TVCBG) which 1. diffracts a first broadband beam propagating at one central wavelength, which satisfies the Bragg condition, and incident on the TVCBG at one of (+) (?) Bragg angles, and 2. transmits at least one second broadband beam propagating at a second central wavelength, which does not satisfy the Bragg condition. The second broadband beam is incident on the TVCBG at the Bragg angle which is opposite to the one Bragg angle of the first broadband beam. The TVCBG is configured to eliminate divergence of the first broadband beam, which is resulted from dispersion of the one TVCBG, in a plane of diffraction, and combine the first diffracted and second transmitted broadband beams into a first single high-power collimated broadband output beam.

Abstract: A beam combiner configured to spectrally combine multiple beams includes at least one pair of identically configured TVBGs. The TVBGs are spaced apart along a light path and aligned at respective “+” and “?” Bragg angles. The upstream TVBGs diffracts a first beam, which is incident thereon at one of the Bragg angles, so that spectral components of this beams diverge from one another defining thus a fan-shaped beam at the output of the upstream TVBG. Upon launching the diffracted first beam to the downstream TVBG at the other Bragg angle, its spectral components again are diffracted but in the direction opposite to that provided by the upstream TVBG. Thus, the dispersion effects in respective TVBGs cancel out each other. Another beam is incident on and transmitted by the downstream TVBG which combines the twice diffracted and transmitted beams into a collimated combined beam.

Abstract: A phase transformation device may include a solid photosensitive material having a planar input facet and one or more reflective holographic phase masks (RHPMs) within a volume of the solid photosensitive material, where a particular one of the one or more RHPMs is formed as a periodic refractive index variation of the photosensitive material along a particular grating vector and further with a particular non-planar lateral phase profile, where at least one of a period of the refractive index variation along the grating vector or an orientation of the grating vector for each of the one or more RHPMs are arranged to reflect via Bragg diffraction light incident on the input facet that satisfies a Bragg condition, and where a phase distribution of the reflected light from a particular one of the one or more RHPMs is modified by the associated non-planar lateral phase profile.

Abstract: A method includes selecting a period for a volume Bragg grating (VBG) such that a spectral selectivity of the VBG is at least as wide as a spectral width of a broadband light beam that is to be spatially transformed, selecting a desired beam transformation for the broadband light beam, passing a first light beam from a recording light source through an optical device to a volume holographic recording medium where the optical device is configured to induce the desired beam transformation, directing a second light beam from the recording light source to the recording medium, and converging the first light beam and the second beam at a recording angle such that a spatial refractive index modulation profile is recorded in the recording medium that provides the VBG with the selected period, and a phase profile is embedded in the VBG that induces the desired beam transformation for each spectral component within a spectral width of the VBG.