Abstract: The present invention relates to a multi-core fiber having a structure for effectively suppressing crosstalk increase between cores caused by bending within an allowable range. The multi-core fiber comprises a plurality of types of cores respectively extending along an optical axis and a cladding region, and the effective refractive index of each core is set so that, in all pairs of cores of different types, a relative refractive index difference between an effective refractive index of a core of a certain type and an effective refractive index of a core of another type satisfies a condition regulated according to a core spacing between cores and a bending radius.

Abstract: An optical fiber (10) includes: a core (11); a first cladding (12) surrounding the core (11) and having a lower refractive index than the core (11); and a second cladding (13) surrounding the first cladding (12) and having a lower refractive index than the first cladding (12). The first cladding (12) is doped with light attenuating dopant so that a concentration of the light attenuating dopant in the first cladding (12) increases from an inner surface of the first cladding (12) toward an outer surface of the first cladding (12).

Abstract: An optical fiber connection structure which reduces MPI in the use of an optical fiber with a bend resistance improved by forming holes in the fiber, and a single-mode fiber which reduces MPI are provided. A second cladding portion of a second single-mode fiber 20 includes holes 28, and thus, the second single-mode fiber 20 has low bending loss. A portion of the second single-mode fiber 20 connected to a first single-mode fiber 10a is made solid by filling corresponding portions of the holes 28 over the length L0, and light in a mode LP11 is significantly attenuated in this portion, thereby reducing MPI.

Abstract: A photonic bandgap fiber includes a first core having a refractive index equal to or smaller than a refractive index of a cladding, a second core that is provided to surround the first core and has a refractive index smaller than the refractive index of the first core, the cladding that surrounds the second core, and a periodic structure portion that is provided in the cladding around the second core, and in which high-refractive index portions having a refractive index larger than the refractive index of the cladding form a periodic structure. The periodic structure is configured such that at least the propagation constant of the fundamental mode at a wavelength to be used is in a photonic bandgap, and the propagation constant of a higher-order mode at the wavelength to be used is outside of the photonic bandgap.

Abstract: Optical fibers and optical transmission systems, which are capable of broadband and large capacity single-mode optical transmission, and have low macrobends are provided. The optical fiber made from pure silica comprising a core region, a cladding region at the circumference of the core region a coating layer made from a resin at the circumference of the cladding region, and having a cutoff wavelength of shorter than 1530 nm, and positive dispersion at 1550 nm, bending loss of less than 10 dB/m at a bending diameter of 20 mm, and an effective core area of 120 ?m2.

Abstract: An optical fiber includes a glass fiber having a glass core and a cladding which contains voids spaced apart from the core. The voids act as trapping sites for ingressing molecules from the surrounding environment, thereby reducing the effect of such molecules on the fiber's light-transmission properties.

Abstract: Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

Abstract: Included among the many structures described herein are photonic bandgap fibers designed to provide a desired dispersion spectrum. Additionally, designs for achieving wide transmission bands and lower transmission loss are also discussed. For example, in some fiber designs, smaller dimensions of high index material in the cladding and large core size provide small flat dispersion over a wide spectral range. In other examples, the thickness of the high index ring-shaped region closest to the core has sufficiently large dimensions to provide negative dispersion or zero dispersion at a desired wavelength. Additionally, low index cladding features distributed along concentric rings or circles may be used for achieving wide bandgaps.

Abstract: There is a problem that in the connection portion between a rare-earth-doped double clad fiber and a single mode fiber, pumping light leaks in a portion having the coating, and the fiber generates heat partially with this energy and deteriorates. Also, there is another problem that the output is limited as the oscillation wavelength becomes shorter. Accordingly, in a laser light source device formed by combining a fiber laser and a fiber amplifier, by using the residual pumping light in the fiber laser as the pumping light in the fiber amplifier, it is possible to enhance the reliability by preventing the fiber deterioration caused by the residual pumping light. Further, by amplifying the output in the fiber amplifier in the latter stage without any limitation on the pumping light output, it is possible to increase an output of the oscillation light.

Abstract: The present invention embraces a single-mode optical fiber that, at a wavelength of 1550 nanometers, has bending losses of 0.15 dB/turn or less for a radius of curvature of 5 millimeters.

Abstract: A bidirectional fiber optic probe comprises an optical in/out coupler and a single fiber or a bundle of fibers, each fiber having a proximal end and a distal end and a numerical aperture NA=sin ?. The numerical aperture NA describes the range of angles over which the optical fiber's proximal end can accept or emit light. The numerical aperture depends on the refractive index n of the fiber core and is given by NA=n sin* ?. ? is the acceptance angle being defined as the half angle of the acceptance cone of the fiber at its proximal end.

Abstract: An all-fiber optical pulse compression arrangement comprises a concatenated arrangement of a section of input fiber (e.g., a single mode fiber), a graded-index (GRIN) fiber lens and a section of pulse-compressing fiber (e.g., LMA fiber). The GRIN fiber lens is used to provide mode matching between the input fiber (supporting the propagation of chirped optical pulses) and the pulse-compressing fiber, with efficient pulse compression occurring along the length of the LMA fiber. The dispersion and length of the LMA fiber section are selected to provide the desired degree of pulse compression; for example, capable of reconstituting a femtosecond pulse as is used in supercontinuum generation systems.

Abstract: An optical fiber with a glass core extending from a centerline to a radius R1 wherein R1 is greater than about 5 ?m; a glass cladding surrounding and in contact with the core. The cladding has a depressed annular region, the inner radius of said depressed annular region is spaced from said core a distance greater than 1 ?m and less or equal to than 5 ?m. The core and the cladding provide a fiber with cable cutoff less than 1550 nm, and an effective area at 1550 nm greater than 120 ?m2 and bend loss of ?0.7 dB/turn on a 20 mm diameter mandrel.

Abstract: A phase-engineered fiber is described for generating a cylindrically polarized beam. The fiber includes a core region, a ring region surrounding the core region, and an outer cladding region surrounding the ring region. The fiber regions are configured to cause the fiber to have a refractive index step proximate to the peak amplitude value of the mode intensity profile of an LP11 mode guided by the fiber. The refractive index step is sufficiently steep such that at least one of the cylindrically polarized TM01 and TE01 eigenmodes has an effective refractive index neff that is sufficiently separated from the respective effective refractive index of the other eigenmodes to allow coupling to the at least one cylindrically polarized eigenmode with minimal coupling to the other eigenmodes.

Abstract: In one embodiment, a fiber optic link includes a combined optical link for transmitting high optical power and wide bandwidth signal through a single optical fiber. In one embodiment, a means is provided for combining a high power optical signal and a low power data signal with wavelength selective directional couplers so as to inhibit the low power data transmitter and the low power data receiver from being overloaded with too much power. In one implementation, a method of using double clad fiber is provided, which includes transmitting an optical data signal at an optical data wavelength along an inner core, the inner core being single mode at the optical data wavelength and simultaneously transmitting an optical power signal at a optical power wavelength through a cladding, the cladding serving as a multimode core for a power optical link at the optical power wavelength.

Abstract: Optical apparatus, comprising an optical fiber having a wavelength of operation, the optical fiber comprising an inner core, the inner core supporting a fundamental mode and at least first and second higher order modes (HOMs) at the wavelength of operation; a first ring-shaped core region spaced from and disposed about the inner core; a second ring-shaped core region spaced from and disposed about the ring-shaped core region; and wherein the optical fiber is configured and arranged such that the first HOM optically interacts with the first ring-shaped core region and the second HOM optically interacts with the second ring-shaped core region.

Abstract: Optical fiber probe tips and methods for fabricating the same are presented. One method entails immersing a distal end of an optical fiber having a cladding and a core into an etching solution and simultaneously etching the cladding and the core using the etching solution for tapering the cladding and the core to form a tapered cladding and a tapered core tip. The optical fiber probe tips are suitable for near-field, scanning, optical microscopy (NSOM).

Abstract: Optical fiber apparatus having a wavelength of operation, that comprises an optical fiber including a core comprising an active material for providing light having the operating wavelength responsive to the optical apparatus receiving pump optical energy having a pump wavelength; a cladding disposed about the core; at least one region spaced from the core; and wherein the optical fiber is configured and arranged such that at the wavelength of operation the optical fiber can propagate a plurality of modes and wherein the optical fiber comprises a fundamental mode that is primarily a mode of the core and at least one higher order mode (HOM) that is a mixed mode of a selected mode of the core and of a selected mode of the at least one region.

Abstract: An optical fiber apparatus having a wavelength of operatic comprises an optical fiber comprising a core; a pump cladding disposed about the core for receiving pump optical energy having a pump wavelength; and a second cladding disposed about for tending to confine pump optical energy to the pump cladding. The core can comprise a rare earth material for providing optical energy having the wavelength of operation responsive to the optical fiber receiving the pump optical energy, and the fiber can further comprise at least one ring core spaced from the core, the ring core defined by inner and outer diameters and comprising the cross sectional area therebetween. The ring core can comprise an absorbing material for absorbing optical energy having the wavelength of operation.

Abstract: A core includes a center core region, a core layer that is formed around the center core region and that has a refractive index lower than that of the center core region, and at least one buffer core layer that is formed between the center core region and the core layer and that has a refractive index lower than that of the center core region and higher than that of the core layer. A cladding is formed around the core layer and that has a refractive index lower than that of the center core region and higher than that of the core layer. An effective core area at a wavelength of 1550 nm is equal to or smaller than 18 ?m2.

Abstract: The present invention relates to a single mode optical fiber comprising a first central region having a radius r1, a maximum refractive index value n1 and at least one second ring surrounding said first central region, which second ring has a radius r2 and a minimum refractive index value n2, wherein n2<n1. The present invention furthermore relates to an optical communication system for multi-channel signal transmission.

Abstract: In an optical fiber (1) for the transmission of high-power laser radiation, with a fiber core (2), with an inner fiber cladding (3) surrounding the fiber core (2) for carrying the laser radiation in the fiber core (2), with a first outer fiber cladding (4) surrounding the inner fiber cladding (3), which has a smaller refractive index than the inner fiber cladding (3) as a result of longitudinally aligned air-filled capillaries (5), and with a second outer fiber cladding (6) surrounding the first outer fiber cladding (4), wherein the first outer fiber cladding (4) has a capillary-free longitudinal section (8), the second outer fiber cladding (6) has according to the invention scattering centers (7) at least in the region of the capillary-free longitudinal section (8) for scattering the laser radiation emerging from the inner fiber cladding (3) along the capillary-free longitudinal section (8).

Abstract: Various embodiments described herein comprise a laser and/or an amplifier system including a doped gain fiber having ytterbium ions in a phosphosilicate glass. Various embodiments described herein increase pump absorption to at least about 1000 dB/m-9000 dB/m. The use of these gain fibers provide for increased peak-powers and/or pulse energies. The various embodiments of the doped gain fiber having ytterbium ions in a phosphosilicate glass exhibit reduced photo-darkening levels compared to photo-darkening levels obtainable with equivalent doping levels of an ytterbium doped silica fiber.

Abstract: A waveguide includes a cladding region that has a refractive index that is substantially uniform and surrounds a wave-guiding region that has an average index that is close to the index of the cladding. The wave-guiding region also contains a thin ring or series of rings that have an index or indices that differ significantly from the index of the cladding. The ring or rings enable the structure to guide light.

Abstract: The invention relates to an optical waveguide capable of extracting light especially from arbitrary positions of the same. An object of the invention is to provide an optical waveguide capable of extracting light efficiently from arbitrary positions of the same. To achieve the above object and according to one aspect of the invention, an optical waveguide is provided with a core for guiding light, a clad and a displacing structure for the core to contact the clad. The core has a first refractive index. The clad has a second refractive index higher than the first refractive index.

Abstract: Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

Abstract: A double-clad optical fiber includes a core, an inner cladding and an outer cladding of silica-based glass. The core may have a radius of less than about 5 ?m, a first index of refraction n1 and does not contain any active rare-earth dopants. The inner cladding may surround the core and includes a radial thickness of at least about 25 ?m, a numerical aperture of at least about 0.25, and a second index of refraction n2 such that n2<n1. The relative refractive index percent (?%) of the core relative to the inner cladding may be greater than about 0.1%. The outer cladding may surround the inner cladding and include a radial thickness from about 10 ?m to about 50 ?m and a third index of refraction n3 such that n3<n2. The relative refractive index percent (?%) of the inner cladding relative to the outer cladding may be greater than about 1.5%.

Abstract: The present invention relates to an optical fiber which has a structure for further increasing an FOM (=|dispersion|/loss) and which can be applied to a dispersion compensation module. The optical fiber is mainly composed of silica glass and has a core region including a center of an optical axis, a depressed region surrounding the core region, a ring region surrounding the depressed region, and a cladding region surrounding the ring region and doped with F. As compared with the refractive index of pure silica glass, a relative refractive index difference of the core region is greater than 2% but less than 3%, a relative refractive index difference of the depressed region is ?1% or more but ?0.5% or less, a relative refractive index difference of the ring region is 0.01% or more but 0.24% or less, and a relative refractive index difference of the cladding region is ?0.3% or more but ?0.1% or less. The FOM at the wavelength of 1550 nm is 250 ps/nm/dB or more.

Abstract: An improved optical fiber achieves both reduced bending and microbending losses, as well as a much higher Brillouin threshold, as compared to standard transmission fibers. The optical fiber comprises a core including at least two dopants and having a refractive index difference ?n1 with an outer optical cladding, a first inner cladding having a refractive index difference ?n2 with the outer cladding, and a depressed, second inner cladding having a refractive index difference ?n3 with the outer cladding of less than ?3×10?3. The radial concentration of at least one of the core dopants varies continuously over the entire core region of the optical fiber.

Abstract: A chalcogenide multi-clad optical fiber having a core, a first cladding and one or more subsequent claddings including a chalcogenide glass. The optical fiber may be capable of transmitting visible and inferred light and may be used for a wide variety of semiconductor applications.

Abstract: A single-mode optical fiber includes a central core, an intermediate cladding, a depressed trench, and an external optical cladding. The central core has a radius r1 and a positive refractive index difference ?n1 with the optical cladding. The intermediate cladding has a radius r2 and a refractive index difference ?n2 with the optical cladding, wherein ?n2 is less than the central core's refractive index difference ?n1. The depressed trench has a radius r3 and a negative index difference ?n3 with the optical cladding. The optical fiber has a nominal mode field diameter (MFD) between 8.6 microns and 9.5 microns at a wavelength of 1310 nanometers, and at a wavelength of 1550 nanometers, the optical fiber has bending losses less than 0.15 dB/turn for a radius of curvature of 5 millimeters and cable cut-off wavelengths of less than or equal to 1260 nanometers.

Abstract: Device for the emission or amplification of a signal, comprising an optical fibre (1) having a solid core (2) of refractive index nc, made of a silica glass doped with a rare earth, such as erbium, ytterbium or neodymium, said core being surrounded by an optical cladding (3, 4, 5, 6, 7, 8) comprising at least a pair of silica layers composed of a first, inner layer (3), having a refractive index greater than the refractive index nc of the core (2), covered by a second, outer layer (4). The optical fibre (1) comprises several pairs of silica layers (3, 4; 5, 6; 7, 8) around the core (2), each pair comprising an inner layer (3, 5, 7) of refractive index ni and an outer layer (4, 6, 8) of refractive index ne, the refractive index ne of the outer layer being lower that the refractive index ni of the inner layer of the same pair.

Abstract: A highly flexible water-proof, rodent-proof cable, comprising an optically or electrically conductive center region, a layer of a yarn of high tensile strength and water blocking properties overlying the center region, a layer of soft annealed steel wires in the form of a braid overlying the yarn layer, and an outer jacket of a polymeric material overlying the steel-wire layer.

Abstract: An optical fiber that concurrently satisfies G.657 and G.652 standards comprises a core region and a cladding region configured to support and guide the propagation of light in a fundamental transverse mode, the cladding region including (i) an outer cladding region having a refractive index nout less than the refractive index n1 of the core region, (ii) an inner cladding region have a refractive index n2 less than nout, (iii) a pedestal (or ring) region having a refractive index n4 approximately equal to nout, (iv) an inner trench region disposed between the inner cladding region and the pedestal region, the inner trench region having a refractive index n3 much less than that of the pedestal region, and (iv) an outer trench region disposed between the pedestal region and the outer cladding region, the outer trench region having a refractive index n5 less than that of the pedestal region and relatively close to that of the outer cladding region.

Abstract: An optical fiber which reduces transmission loss increase even in a high humidity environment or under water is provided. To solve the above issue, an optical fiber according to the present invention comprises a glass optical fiber coated with at least two coating layers, soft and hard layers. The optical fiber is further coated by a colored resin to make a colored optical fiber. The hard layer and the color layer of the colored optical fiber have a free volume radius of at least 0.290 nm according to positron annihilation lifetime spectroscopy.

Abstract: An optical waveguide fiber is provided that includes a core and a cladding, where the core includes an alpha profile, wherein alpha (?) is greater than 2.5 and less than 3.0. The core and the cladding provide a fiber with an attenuation of less than 0.331 dB/km at a wavelength of 1310 nm, an attenuation of less than 0.328 dB/km at a wavelength of 1383 nm, an attenuation of less than 0.270 dB/km at a wavelength of 1410 nm, and an attenuation of less than 0.190 dB/km at a wavelength of 1550 nm. Methods for producing the optical fiber are also provided.

Abstract: The invention consists in an amplifying optical fiber comprising a core containing a dopant and a cladding, wherein said core comprises a monomode core intended to propagate an optical signal, quantum dots of a semiconductor material being disposed in or near said monomode core, and a multimode core surrounding the monomode core, intended to receive a pumping signal.

Abstract: Described are multimode optical fibers in which the differential in the mode delay for higher order modes is reduced for bending insensitive MMF. The result is preservation of low differential mode delay and high bandwidth while low bend loss is achieved. The designs are based on choosing a combination of a core profile and a cladding structure with a negative trench positioned at a radius related to the core profile. A feature of the preferred embodiments is a core with a hybrid refractive index profile. The hybrid refractive index profile is essentially a combination of a standard alpha profile and a step profile at the outer edge of the alpha profile.

Abstract: Various embodiments described herein include rare earth doped glass compositions that may be used in optical fiber and rods having large core sizes. Such optical fibers and rods may be employed in fiber lasers and amplifiers. The index of refraction of the glass may be substantially uniform and may be close to that of silica in some embodiments. Possible advantages to such features include reduction of formation of additional waveguides within the core, which becomes increasingly a problem with larger core sizes.

Abstract: An optical fiber comprising: (i) a glass core (20) extending from a centerline and including a central core region (22) with an alpha value of less than 2, a first annular core region (24)surrounding the central core region (22), and a second annular core region (26) surrounding the first annular core region (24), wherein the second annular core region (26) has a higher maximum relative refractive index percent ?26MAX than that maximum relative refractive index percent ?24MAX of the first annular core region (24); and (ii) a glass cladding (30) surrounding and in contact with the core (20), the cladding comprising: (a) a first annular cladding region (32) extending from a radius RC3 to a radius R32, (b) a second annular cladding region (34) extending from the radius R32 to a radius R34, (c) a third annular cladding region (36) surrounding the second annular region (34) and extending from the radius R34 to an outermost glass radius R36; wherein the core (20) comprises a maximum relative refractive index percen

Abstract: A single mode optical fiber comprises: (i) a segmented core having at least three segments and (ii) a silica based clad layer surrounding and in contact with the core, the clad layer having a refractive index nc. The first segment has a ?max % in the range of about 0.75 to 1.1, and ?0%?0.6?max %, and an outer radius r1 in the range of about 1.5 to 3.0 ?m. The second segment has a ?2% in the range of 0.00 to 0.15%. The third segment has a ?3% in the range of less than 0.35%, an outer radius r3 in the range of about 7 ?m to 11 ?m, a width w3 in the range of about 1.5 to 3 ?m, and volume V3<7% ?m2. The refractive index profiles of the core segments are selected to provide: zero dispersion wavelength in the range of about 1565 nm to 1600 nm; total dispersion at 1550 nm in the range of about ?6 to ?0.5 ps/nm-km; and dispersion slope at 1550 nm is greater than 0.1.

Abstract: A phase-engineered fiber is described for generating a cylindrically polarized beam. The fiber includes a core region, a ring region surrounding the core region, and an outer cladding region surrounding the ring region. The fiber regions are configured to cause the fiber to have a refractive index step proximate to the peak amplitude value of the mode intensity profile of an LP11 mode guided by the fiber. The refractive index step is sufficiently steep such that at least one of the cylindrically polarized TM01 and TE01 eigenmodes has an effective refractive index neff that is sufficiently separated from the respective effective refractive index of the other eigenmodes to allow coupling to the at least one cylindrically polarized eigenmode with minimal coupling to the other eigenmodes.

Abstract: An optical fiber adapted to carry optical power for powering an electrical device and also optionally adapted to carry optical data for signal processing. The optical fiber capable of carrying both optical data and optical power includes a central data waveguide region that carries data light and an annular power waveguide region concentrically surrounding the data waveguide region and adapted to carry relatively large amounts of optical power. A first annular isolation region between the data and power waveguide regions and that includes microstructures serves to optically isolate the waveguide regions. An outer annular isolation region serves to confine power light to the power waveguide region and contributes to the bend-resistance of the optical fiber. An optical power and optical data distribution system that utilizes the optical fiber is also described.

Abstract: A cable is provided including an inner member, an outer member and an intermediate member. The intermediate member may be positioned between the inner member and the outer member and include a number of disconnection sections spaced apart from one another. In some cases, the cable may include two or more inner members. In addition, a method for preparing an end of a cable may be provided, including the steps of removing a portion of an outer member of the cable and applying a tensile force to an intermediate member of the cable comprising a plurality of disconnection sections.

Abstract: An optical fiber suitable for high-capacity transmission having a large effective core area, a low bending loss, and capable of single mode operation at 1550 nm is provided. The optical fiber 10 has an effective core area?175 ?m2 at 1550 nm, a bending loss?10 dB/m at a bending diameter of 20 mm at 1550 nm, and a cut-off wavelength ?c?1550 nm. The optical fiber has a first core 11 at the center, which has a refractive index higher than that of the cladding 13; and a second core 12 around the first core 11, which has a refractive index lower than that of the cladding 13; a primary medium portion; and secondary medium portions, which have a refractive index lower than that of the primary medium portion and the secondary medium portions have a plurality of first secondary medium portions 15 around the first core 11 and a plurality of second secondary medium portions 16 around the first core 11 and outside of the first secondary medium portions 15.

Abstract: An optical fiber is constituted by: a three-layer structured core which includes, a first core (having a relative refractive index difference of ?1 in a region of a radius of R1), a second core (having a relative refractive index difference of ?2 in a region from the radius R1 to a radius of R2), and a third core (having a relative refractive index difference of ?3 in a region from the radius of R2 to a radius of R3), wherein the relative refractive index differences have relationships of ?1>?2, ?3>?2, and ?3>?1, when ?1??2=X and ?3??2=Y, (X+Y)>0.4% is satisfied, and X and Y satisfy 0.25%<X<0.6%, 0.1%?Y?0.6%, and a relationship of (2*X?0.7)%<Y<(X/2+0.4)%, thereby satisfying the G652 standard and having an SBS threshold equal to or higher than that of an optical fiber having the same MFD by +3 dB or higher.

Abstract: The present invention relates to an optical fiber which has a structure for further increasing an FOM (=|dispersion|/loss) and which can be applied to a dispersion compensation module. The optical fiber is mainly composed of silica glass and has a core region including a center of an optical axis, a depressed region surrounding the core region, a ring region surrounding the depressed region, and a cladding region surrounding the ring region and doped with F. As compared with the refractive index of pure silica glass, a relative refractive index difference of the core region is greater than 2% but less than 3%, a relative refractive index difference of the depressed region is ?1% or more but ?0.5% or less, a relative refractive index difference of the ring region is 0.01% or more but 0.24% or less, and a relative refractive index difference of the cladding region is ?0.3% or more but ?0.1% or less. The FOM at the wavelength of 1550 nm is 250 ps/nm/dB or more.

Abstract: An optical waveguide has a refractive index variation that is structured to provide the fiber, over a wavelength operating range, with an effective area supporting multiple Stokes shifts and with a negative dispersion value at a target wavelength within the wavelength operating range. The refractive index variation is further structured to provide the fiber with a finite LP01 cutoff at a wavelength longer than the target wavelength, whereby the LP01 cutoff wavelength provides a disparity, for a selected bending diameter, between macrobending losses at the target wavelength and macrobending losses at wavelengths longer than the target wavelength, whereby Raman scattering is frustrated at wavelengths longer than the target wavelength.

Abstract: Optical die structures and associated package substrates are generally described. In one example, an electronic device includes a package substrate having a package substrate core, a dielectric layer coupled with the package substrate core, and one or more input/output (I/O) optical fibers coupled with the package substrate core or coupled with the build-up dielectric layer, or combinations thereof, the one or more I/O optical fibers to guide I/O optical signals to and from the package substrate wherein the one or more I/O optical fibers allow both input and output optical signals to travel through the one or more I/O optical fibers.

Abstract: An optical fiber amplifier includes a laser pump source for generating laser pump light; a fiber including an inner cladding layer optically coupled to a laser pump source for receiving laser pump light; a large mode area (LMA) core surrounded by the inner cladding, the LMA core including a confined region having a predetermined doping concentration of rare-earth ions for undergoing excitation to generate laser light when pumped by the laser pump light; and an outer cladding layer surrounding the inner cladding layer for substantially confining the laser pump light to the inner cladding and the LMA core. In a method of forming the optical fiber amplifier, a ratio of an area of the confined region to an area of the LMA core, and the predetermined doping concentration of the rare earth ions are selected so as to achieve a quantum efficiency (QE) gain factor of approximately 2, but such that the heat dissipation per unit length can be controlled by adjusting the area of the confined region.