University of Central Florida Research Foundation, Inc.

Ipg Photonics Corporation

Ivan Divliansky

Leonid B Glebov

Lam Mach

Evan Hale

Vadim Smirnov

George Venus

Boris Zeldovich

Bahaa Saleh

Oussama Mhibik

Leonid Glebov

Brian Anderson

Daniel Ott

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.

Achromatic holographic phase masks

An imaging element may include volume Bragg grating (VBG) within a material, where the material has an input face, and where the VBG is formed as a periodic distribution of curved surfaces of refractive index variation with chirped periodicity in a volume of the material. The periodic distribution of curved surfaces of refractive index variation forming the VBG may be selected to image different object planes oriented parallel to the input face onto different lateral locations of a single image plane with different wavelengths via the Bragg diffraction.

All-optical volumetric imaging via spectral sweep by means of a transmissive bragg grating featuring a radially dependent plane of diffraction

A phase-shifted longitudinally-chirped volume Bragg grating (PS-LCVBG) may be formed as a solid block of photosensitive material having a planar input face, where the photosensitive material includes a VBG formed as a periodic volumetric refractive index distribution characterized by a grating vector direction. A period of the VBG may longitudinally chirped to vary linearly along the grating vector direction. The VBG may further include a spatially-varying distribution of longitudinal phase shifts providing a spatially-varying distribution of reflectivity in a transverse plane normal to the grating vector direction, where light incident on the planar input face is at least partially reflected based on the spatially-varying distribution of reflectivity.

Phase-shifted, chirped volume Bragg gratings

A phase converting device capable of use over a broad wavelength range, which may be used for optical beam transformations and combining, conversion of resonator and waveguide modes, correction of aberrations in optical systems, and selection of photons with specific phase profile. This provides significant advantages in high power laser systems. Large-mode-area fibers can be used to provide higher incident powers than can be achieved by single-mode fibers, reducing the number of elements in a system necessary to achieve the desired output. The profiles of these LMA fiber modes can then be converted from the undesired modes into the desired mode while combing their total power into a single beam.

Achromatic holographic phase masks, methods, and applications

A method of reversible spatial mode selection and conversion between waveguides and free space is presented using a multiplexed volume Bragg grating (MVBG). The MVBG has an inherent angular selectivity, providing different losses for different transverse modes and converting a higher order mode in waveguide to a single fundamental mode in free space. Using the device in a resonator allows for a pure higher order mode to be guided and amplified in the gain medium, to increase the mode area, to extract accumulated excitation more efficiently, and, therefore, to increase gain of the amplifier. In the same resonator, the device is able to convert the higher order mode to a high brightness Gaussian beam in free space or to a fundamental mode in a waveguide.

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Orlando, FL, United States of America

Ivan Divliansky