Optical switch and Q-switched laser

Claim 2

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.

Claim 3

The optical switch according to claim 1, wherein said pad has a length between 100 and 1000 times a diameter of the core.

Claim 4

The optical switch according to claim 2, wherein said length is about 400 times a diameter of the core.

Claim 5

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.

Claim 6

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.

Claim 7

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.

Claim 8

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.

Claim 9

The optical switch according to claim 5, further comprising means for rapidly discharging said translator and slowly recharging said translator.

Claim 10

The optical switch according to claim 5, further comprising feedback means including a light detector for detecting light travelling in said fiber and attenuated by said pad, and means for recharging said translator until attenuation has reached a predetermined complete level.

Claim 11

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.

Claim 12

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.

Claim 13

Laser as claimed in claim 8, wherein said medium comprises a monomode doped optical fiber.

Claim 14

Laser as claimed in claim 9, wherein said optical fiber is erbium doped.

Claim 15

Laser according to claim 8, wherein said pad is made of a dielectric having an index of refraction greater than an index of refraction of said cavity.

Claim 16

Laser according to claim 8, wherein said pad is a conductor, said pad providing control over the transverse magnetic mode of light passing through said cavity, and further comprising a polarizer to eliminate transverse electric modes.

Claim 17

Laser according to claim 8, wherein said means for translating comprise a piezoelectric translator.

Claim 18

Laser according to claim 13, 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.

Claim 19

Laser according to claim 14, further comprising means for rapidly discharging said translator and slowly recharging said translator.

Claim 20

Laser according to claim 14, further comprising feedback means including a light detector for detecting light travelling in said fiber and attenuated by said pad, and means for recharging said translator until attenuation has reached a predetermined complete level.

Claim 21

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.

Claim 22

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.

Claim 23

Laser as claimed in claim 17, wherein said pad is provided near a middle of said cavity.