Back to results
US 6,031,849 AGranted
High power three level fiber laser and method of making same
AssigneeJDS Uniphase Corporation
InventorsGary A. Ball, Paul Sanders
Life of this patent
Estimating the term…
Abstract
A rare earth doped fiber for use in a fiber laser is presented. The fiber laser uses a single stripe broad area pump diode permits Yb lasing in its 3-level transition at 980 nm preferentially over the 1010 nm 4-level transition. The present fiber laser is characterized by a dual cladding fiber geometry which includes an inner rare earth doped single mode core. There is an inner cladding designed to be a multimode pump core for the pump light. The pump core is followed by a final cladding to confine the pump radiation. The present laser matches the larger/outer mode field to that of a single stripe broad area diode in order to maximize the pump intensity.
Claims27
A method of fabricating a rare earth doped fiber for use in a fiber laser, said method comprising the steps of:
- providing a silica substrate tube;
- depositing a layer of homogenous silica glass film on said silica substrate tube;
- doping said silica glass film with index-raising dopants to form an outer cladding;
- depositing a soot deposit of silica to form an inner core having an index of refraction greater than said outer cladding;
- soaking said fiber in a fare earth element-containing solution to dope the soot material and form a composite preform fiber;
- heating said composite preform fiber to form a consolidated fiber;
- grinding in said consolidated fiber a pair of slots equal in magnitude and opposing one another about an axis of said inner core;
- heating said slot ground fiber to a temperature at which the silica flows to form an inner cladding about said inner core.
5 more elements
An optical fiber for use in a fiber laser made in accordance with a method comprising the steps of:
- providing a silica substrate tube;
- depositing a layer of homogenous silica glass film on said silica substrate tube;
- doping said silica glass film with index-raising dopants to form an outer cladding;
- depositing a soot deposit of silica to form an inner core having an index of refraction greater than said outer cladding;
- soaking said fiber in a rare earth element-containing solution to dope the soot material and form a composite preform fiber;
- heating said composite preform fiber to form a consolidated fiber;
- grinding in said consolidated fiber a pair of slots equal in magnitude and opposing one another about an axis of said inner core;
- and
- heating said slot ground fiber to a temperature at which the silica flows to form an inner cladding about said inner core.
6 more elements
A fiber laser comprising:
- an optical pumping means for generating an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing refection of said laser signal of a selected magnitude;
- and
- a second reflector positioned adjacent said second optical fiber end for providing refection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector.
6 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said inner cladding has about 4 mm by 100 mm cross sectional dimensions.
7 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said inner core is centered in said inner cladding which has a cross section between 50 mm and 100 mm as a diameter.
7 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said fiber inner core is doped with Ytterbium (Yb) and said optical pumping signal has a wavelength of approximately 917 nm and a power of about 1.5 W.
7 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said optical pumping means further comprises a broad area multi-transverse mode diode laser.
7 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said laser signal has a wavelength of approximately 974 nm.
7 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said outer cladding has a circular geometry directly compatible with a receiving end of a 125 mm optical fiber.
7 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said optical pumping signal is sufficient to enable 3-level transition operation.
7 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said laser signal has a wavelength of approximately 1.5 mm.
7 more elements
A fiber laser comprising:
- an optical pumping means for providing an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing reflection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing reflection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- and
- wherein said inner cladding optically communicates sufficiently with said optical pumping signal to enable 3-level transition operation.
7 more elements
A laser amplifier for amplifying an input optical signal, comprising:
- a rare earth element doped optical fiber for receiving the input optical signal;
- an optical coupler for coupling a coherent optical pumping signal to said rare earth doped optical fiber;
- a fiber laser for providing said coherent optical pumping signal to said optical coupler, said fiber laser having
- an optical pumping means for generating an optical pumping signal in response to command signals;
- a dual clad optical fiber having a first end for receiving said optical pump signal and a second end for presenting a laser signal, said fiber including
- an inner core for providing single mode transmission of said laser signal;
- an inner cladding disposed adjacent said inner core for providing a pump core configured to match a laser mode field geometry of said optical pumping signal to optically couple said optical pumping signal to said inner core;
- and
- an outer cladding disposed adjacent said inner cladding having an index of refraction less than said inner cladding for confining said optical pumping signal;
- a first reflector positioned adjacent said first optical fiber end for providing refection of said laser signal of a selected magnitude;
- a second reflector positioned adjacent said second optical fiber end for providing refection of said laser signal of a magnitude selected to be substantially less than the reflection magnitude of said first reflector;
- a pickoff coupler adapted to receive said laser signal from said second reflector for providing a feedback signal indicative of said laser signal power;
- and
- a controller for providing command signals to said optical pumping means in response to said feedback signal to operate said optical pumping means at a select power.
11 more elements
Dependencies are inferred from the claim text.