US 2024/0413609 A1Published application

Pulsed optical source

AssigneeUniversity of Southampton

InventorsPeter George Robin SMITH, Rex Hugh Seton BANNERMAN, Devin Hugh SMITH

Life of this patent

Estimating the term…

Loading patent…

Abstract

An optical source comprises: a pump source operable to generate laser light at a first wavelength; a single mode optical fibre arranged to receive laser light at the first wavelength from the pump source, the optical fibre being fabricated from material having a Raman gain profile for stimulated Raman scattering of light at the first wavelength, and a Brillouin gain profile for stimulated Brillouin scattering of light at the second wavelength to a third wavelength longer than the second wavelength; and a superstructured fibre Bragg grating formed in the optical fibre, the grating comprising: a periodic refractive index profile along a core of the optical fibre, giving transmission of the first wavelength to allow received laser light at the first wavelength to enter the superstructured fibre Bragg grating, reflection of the second wavelength at a first level, and reflection of the third wavelength at a second level lower than the first level; and a phase shift at an intermediate location along a length of the grating; wherein the series of pulses at the third wavelength comprise a pulsed output of the optical source.

Claims24

Dependent claims

An optical source comprising:

a pump source operable to generate laser light at a first wavelength;
a single mode optical fibre arranged to receive laser light at the first wavelength from the pump source, the optical fibre being fabricated from material having a Raman gain profile for stimulated Raman scattering of light at the first wavelength such that received laser light at the first wavelength experiences stimulated Raman scattering within the optical fibre to a second wavelength longer than the first wavelength, and a Brillouin gain profile for stimulated Brillouin scattering of light at the second wavelength to a third wavelength longer than the second wavelength;
and
a superstructured fibre Bragg grating formed in the optical fibre, the grating comprising:
a periodic refractive index profile along a core of the optical fibre, giving transmission of the first wavelength to allow received laser light at the first wavelength to enter the superstructured fibre Bragg grating, reflection of the second wavelength at a first level, and reflection of the third wavelength at a second level lower than the first level;
and
a phase shift at an intermediate location along a length of the grating to create, via the reflection at the first level, a resonant cavity for the second wavelength that enables light at the second wavelength to reach an intracavity power sufficient for the stimulated Brillouin scattering to occur so that light at the second wavelength undergoes a wavelength shift to the third wavelength until the intracavity power at the second wavelength becomes insufficient for the stimulated Brillouin scattering to occur, the light at the third wavelength coupling out of the resonant cavity, via the reflection at the second level, as a series of pulses corresponding to the intracavity power at the second wavelength being sufficient for the stimulated Brillouin scattering to occur;
wherein the series of pulses at the third wavelength comprises a pulsed output of the optical source.

5 more elements

A method for generating optical pulses, comprising:

delivering pump laser light at a first wavelength into a resonant cavity, where the resonant cavity is formed in single mode optical fibre fabricated from material having a Raman gain profile for stimulated Raman scattering of the pump laser light at the first wavelength such that the delivered pump laser light at the first wavelength experiences stimulated Raman scattering within the optical fibre to a second wavelength longer than the first wavelength, and having a Brillouin gain profile for stimulated Brillouin scattering of light at the second wavelength to a third wavelength longer than the second wavelength;
wherein the resonant cavity comprises a superstructured fibre Bragg grating comprising:
a periodic refractive index profile along a core of the single mode optical fibre, giving transmission of the first wavelength to allow the pump laser light at the first wavelength to enter the superstructured fibre Bragg grating, reflection of the second wavelength at a first level, and reflection of the third wavelength at a second level lower than the first level;
and
a phase shift at an intermediate location along a length of the grating to create, via the reflection at the first level, the resonant cavity for resonance of the second wavelength that enables light at the second wavelength to reach an intracavity power sufficient for the stimulated Brillouin scattering to occur so that light at the second wavelength undergoes a wavelength shift to the third wavelength until the intracavity power at the second wavelength becomes insufficient for the stimulated Brillouin scattering to occur, the light at the third wavelength coupling out of the resonant cavity, via the reflection at the second level, as a series of pulses corresponding to the intracavity power at the second wavelength being sufficient for the stimulated Brillouin scattering to occur;
and
taking the series of pulses at the third wavelength as the generated optical pulses.

4 more elements

Dependencies are inferred from the claim text.