Method and optical gain fiber having segments of differing core sizes
First Claim
1. An apparatus comprising:
- an optical-fiber amplifier having a plurality of optically coupled gain-fiber segments, including;
a first gain-fiber segment, wherein the first segment has a first core that is surrounded by a first inner cladding, wherein the first inner cladding is surrounded by a first outer cladding;
a second gain-fiber segment that is joined to the first segment at a first junction, wherein the second segment includes a second core that is surrounded by a second inner cladding, wherein the second inner cladding is surrounded by a second outer cladding, wherein an outer diameter of the first inner cladding of the first gain-fiber segment at the first junction is smaller than an outer diameter of the second inner cladding of the second gain-fiber segment at the first junction, wherein signal light of a signal-light wavelength is coupled into the first core, and wherein the signal light is coupled from the first core into the second core; and
a first plurality of pump-light-input ports joined to the optical-fiber amplifier at the first junction.
4 Assignments
0 Petitions
Accused Products
Abstract
Apparatus and method for amplifying laser signals using segments of fibers of differing core diameters and/or differing cladding diameters to suppress amplified spontaneous emission and non-linear effects such as four-wave mixing (FWM), self-phase modulation, and stimulated Brillouin and/or Raman scattering (SBS/SRS). In some embodiments, different core sizes have different sideband spacings (spacing between the desired signal and wavelength-shifted lobes). Changing core sizes and providing phase mismatches prevent buildup of non-linear effects. Some embodiments further include a bandpass filter to remove signal other than the desired signal wavelength and/or a time gate to remove signal at times other than during the desired signal pulse. Some embodiments include photonic-crystal structures to define the core for the signal and/or the inner cladding for the pump. Some embodiments include an inner glass cladding to confine the signal in the core and an outer glass cladding to confine pump light in the inner cladding.
-
Citations
20 Claims
-
1. An apparatus comprising:
an optical-fiber amplifier having a plurality of optically coupled gain-fiber segments, including; a first gain-fiber segment, wherein the first segment has a first core that is surrounded by a first inner cladding, wherein the first inner cladding is surrounded by a first outer cladding; a second gain-fiber segment that is joined to the first segment at a first junction, wherein the second segment includes a second core that is surrounded by a second inner cladding, wherein the second inner cladding is surrounded by a second outer cladding, wherein an outer diameter of the first inner cladding of the first gain-fiber segment at the first junction is smaller than an outer diameter of the second inner cladding of the second gain-fiber segment at the first junction, wherein signal light of a signal-light wavelength is coupled into the first core, and wherein the signal light is coupled from the first core into the second core; and a first plurality of pump-light-input ports joined to the optical-fiber amplifier at the first junction. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
8. A method comprising:
-
providing a plurality of amplifying fiber segments includes a first amplifying segment and a second amplifying segment that are joined to one another at a first junction, and a first plurality of pump-light-input ports connected at the first junction, wherein the first amplifying segment includes a first core that is surrounded by a first inner cladding, wherein the first inner cladding is surrounded by a first outer cladding, wherein the second amplifying segment includes a second core that is surrounded by a second inner cladding, wherein the second inner cladding is surrounded by a second outer cladding, wherein an outer diameter of the first inner cladding of the first amplifying segment at the first junction is smaller than an outer diameter of the second inner cladding of the second amplifying segment at the first junction; injecting pump light through the first plurality of pump-light-input ports at the first junction; coupling signal light of a signal-light wavelength into the first core; amplifying the signal light in the first amplifying segment to generate first-amplified signal light; coupling the first-amplified signal light from the first core into the second core; and further amplifying the first-amplified signal light in the second segment to generate second-amplified signal light. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. An apparatus comprising:
-
a plurality of amplifying fiber segments that includes a first amplifying segment and a second amplifying segment that are joined to one another at a first junction, wherein the first amplifying segment includes a first core that is surrounded by a first inner cladding, wherein the first inner cladding is surrounded by a first outer cladding, wherein the second segment includes a second core that is surrounded by a second inner cladding, wherein the second inner cladding is surrounded by a second outer cladding, wherein an outer diameter of the first inner cladding of the first amplifying segment at the first junction is smaller than an outer diameter of the second inner cladding of the second amplifying segment at the first junction; means for injecting pump light at the first junction; means for coupling signal light of a signal-light wavelength into the first core; means for amplifying the signal light in the first amplifying segment to generate first-amplified signal light; means for coupling the first-amplified signal light from the first core into the second core; and means for further amplifying the first-amplified signal light in the second amplifying segment to generate second-amplified signal light. - View Dependent Claims (16, 17, 18, 19, 20)
-
Specification