Transient bragg gratings in optical waveguides and their applications
AssigneeB.G. Negev Technologies and Applications Ltd., At Ben-Gurion University
InventorsAmiel ISHAAYA, Yonatan SIVAN
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Abstract
A method for obtaining transient Bragg gratings in optical waveguides and several different applications of the transient Bragg gratings obtained using this method are presented. The basic mechanisms for obtaining the transient gratings in the waveguides are refractive index change due to Kerr nonlinearity, free carrier generation, and gratings formed by linear or non-linear absorption of thermal energy. The exemplary applications include an ultra-fast fiber laser source at any central wavelength, a fast spectral switch/modulator, transient pulse stretchers based on transient chirped gratings, Q-switching based on transient gratings, and time reversal of ultra-short pulses and low power sub-nanosecond pulse generations.
Claims16
An optical setup for forming a transient Bragg grating in an optical waveguide, the optical setup comprising:
- a) an ultra-fast laser configured to emits high intensity ultra-fast pulses;
- b) a cylindrical lens configured to form radiation emitted by the laser into a line that is focused on the optical waveguide;
- and
- c) a phase mask located between the aperture and the optical waveguide;
- wherein, diffraction patterns created by the phase mask for each pulse interfere to create refractive index changes at high intensity points along the waveguide at a spatial period determined by the phase mask, the wavelength, and the specific material of the waveguide, such that said refractive index changes are reversed when the radiation ceases to be focused on the waveguide, thereby forming a transient Bragg grating.
Dependencies are inferred from the claim text.