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US 5,444,723 AGranted
Optical switch and Q-switched laser
AssigneeInstitut National D'Optique
InventorsAlain Chandonnet, Gilles Larose
Life of this patent
Estimating the term…
Abstract
A length of an optical fiber having a core and a surrounding cladding is held by a block with a portion of said length having substantially all of its cladding removed on one side of the portion and being exposed, and an index overlay perturbation pad is mounted near and substantially parallel to the portion. A translator moves the pad between a first position in which the pad is sufficiently remote from the portion to allow total internal reflection in the portion and a second position in which the pad is sufficiently close to the portion to allow light to escape from the core. The pad may be made of a metal for polarized modulation, or of a dielectric for unpolarized modulation. The optical switch provides very fast switching for a O-switched fiber laser.
Claims18
An optical switch comprising:
- means for holding a length of an optical fiber having a core and a surrounding cladding, with a portion of said length having substantially all of its cladding removed on one side of said portion and being exposed, said means surrounding said length except on said one side;
- an index overlay perturbation pad substantially matching with said side of the portion;
- means for mounting the pad near and substantially parallel to said portion, said mounting means including means for translating said pad between a first position in which said pad is sufficiently remote from said portion to allow total internal reflection in said portion and a second position in which said pad is sufficiently close to said portion and is lying evenly and parallel on top of said portion to allow light to escape from said core;
- and
- wherein said pad is made of a dielectric having an index of refraction greater than an index of refraction of the core.
2 more elements
An optical switch comprising:
- means for holding a length of an optical fiber having a core and a surrounding cladding, with a portion of said length having substantially all of its cladding removed on one side of said portion and being exposed, said means surrounding said length except on said one side;
- an index overlay perturbation pad substantially matching with said side of the portion;
- means for mounting the pad near and substantially parallel to said portion, said mounting means including means for translating said pad between a first position in which said pad is sufficiently remote from said portion to allow total internal reflection in said portion and a second position in which said pad is sufficiently close to said portion and is lying evenly and parallel on top of said portion to allow light to escape from said core;
- and
- wherein said pad is a conductor, said optical switch providing control over the transverse magnetic mode of light passing through said optical fibre.
2 more elements
An optical switch comprising:
- means for holding a length of an optical fiber having a core and a surrounding cladding, with a portion of said length having substantially all of its cladding removed on one side of said portion and being exposed, said means surrounding said length except on said one side;
- an index overlay perturbation pad substantially matching with said side of the portion;
- means for mounting the pad near and substantially parallel to said portion, said mounting means including means for translating said pad between a first position in which said pad is sufficiently remote from said portion to allow total internal reflection in said portion and a second position in which said pad is sufficiently close to said portion and is lying evenly and parallel on top of said portion to allow light to escape from said core;
- wherein said means for translating comprise a piezoelectric translator;
- wherein said pad is made of a dielectric having an index of refraction greater than an index of refraction of the core;
- and
- wherein said second position is in contact with said portion, said translator being charged when said pad is in contact and discharged when said pad is in said first position.
4 more elements
A Q-switched laser comprising:
- a small cross-section resonant cavity including a laser medium, said cavity having a higher index of refraction than a material surrounding the cavity, lateral reflectivity of said cavity being provided by internal reflection, a portion of said cavity having substantially all of its surrounding material removed on one side of said portion;
- a pumping light source coupled with the cavity to inject light along said cavity;
- an index overlay perturbation pad substantially matching with said side of the portion;
- means for mounting said pad near and substantially parallel to said portion, said mounting means including means for translating said pad between a first position in which said pad is sufficiently remote from said portion to allow internal reflection in said portion and a second position in which said pad is sufficiently close to said portion and is lying evenly and parallel on top of said portion to allow light to escape from said cavity;
- and
- wherein said pad is made of a dielectric having an index of refraction greater than an index of refraction of said cavity.
3 more elements
A O-switched laser comprising:
- a small cross-section resonant cavity including a laser medium, said cavity having a higher index of refraction than a material surrounding the cavity, lateral reflectivity of said cavity being provided by internal reflection, a portion of said cavity having substantially all of its surrounding material removed on one side of said portion;
- a pumping light source coupled with the cavity to inject light along said cavity;
- an index overlay perturbation pad substantially matching with said side of the portion;
- means for mounting said pad near and substantially parallel to said portion so that the pad and said side of the portion substantially match together, said mounting means including means for translating said pad between a first position in which said pad is sufficiently remote from said portion to allow internal reflection in said portion and a second position in which said pad is sufficiently close to said portion and is lying evenly and parallel on top of said portion to allow light to escape from said cavity;
- and
- wherein said pad has an index of refraction lower than the index of refraction of said cavity at a wavelength of the pumping light, and an index of refraction higher than the index of refraction of said cavity at a wavelength of laser light of said medium.
3 more elements
Dependencies are inferred from the claim text.