Abstract: An all-fiber laser oscillator comprises a laser cavity, an amplification fiber, a plurality of diode lasers, and at least one side-pump signal-and-pump combiner (combiner). The combiner comprises a double-clad fiber (DCF) and four or more multimode fibers (MMFs). DCF comprises a first taper portion, whereas each of MMFs comprises a second taper portion fused around DCF. MMFs are configured to carry a portion of combined optical energy (COE) and to couple to DCF. The first taper portion can partially compensate a beam divergence created by the second taper portion, thereby increasing a coupling efficiency of COE coupled from MMFs to DCF with improved thermal performance. In a coupling portion, a refractive index difference between MMFs and DCF is configured to form a backward coupling barrier to suppress an optical energy in DCF from coupling into MMFs, thereby protecting the plurality of diode lasers from damage.

Abstract: An optical fiber component includes a plurality of optical fibers bundled together at one end at least. The plurality of optical fibers includes a first optical fiber centered at the one end and a plurality of second optical fibers disposed around the first optical fiber at the one end. Each of the plurality of second optical fibers has, at the one end, an end face shape including a straight portion and a corner portion.

Abstract: An optoelectronic package is provided. The optoelectronic package includes a photonic component. The photonic component has a bottom surface and a lateral surface. The lateral surface of the photonic component includes a light coupling region and a non-light coupling plane. The non-light coupling plane contacts the bottom surface. The light coupling region and the non-light coupling plane are not aligned.

Abstract: An object is to provide an optical communication system and an optical communication method that are capable of, when assigning wavelengths on a per-service basis and providing services on a per-area basis, preventing degradation of signal quality due to linear crosstalk and preventing an increase in cost and size. An optical communication system according to the present invention includes an optical splitter 300 connecting N first ports and M second ports by a combination of 2×2 fiber optical splitters, N and M each being an integer of two or more, where wavelengths of optical signals to be received are limited for each group of optical receivers 106, by using a correlation between a fused extension length of at least one 2×2 fiber optical splitter directly connected to the first port, among the 2×2 fiber optical splitters, and wavelength output characteristics of the second port of the optical splitter 300.

Abstract: A laser system is provided. The laser system comprises: a seed laser configured to produce a sequence of seed light pulses, wherein the sequence of seed light pulses are produced with variable time intervals in a sweep cycle; a pump laser configured to produce pump light having variable amplitude in the sweep cycle; and a control unit configured to generate a command to the pump laser to synchronize the pump light with the sequence of seed light pulses.

Abstract: An optical transceiver includes a housing and an optical receptacle; optical subassemblies each having a sleeve and being configured to perform a photoelectric conversion, the sleeve facing to the optical receptacle; inner fibers each connected to the sleeve one to one; and a tray having a holding part and a guiding part, the holding part holding the optical subassemblies in line, the guiding part being formed on both outer sides of the holding part and a folding back area on an opposite side of the optical receptacle. The guiding part includes a pair of passage parts. The inner fiber passes through one of the passage parts, the folding back area, and another of the passage parts in this order within the tray so as to face the optical receptacle again when the another of the passage parts is closer to the sleeve than the one of the passage parts.

Abstract: A process of welding a superalloy is provided. The process includes applying a first amount of energy to a substrate comprised of the superalloy to form a melt pool along a length of the substrate and in a weld direction. The process also comprises advancing the melt pool in the weld direction along the length via the first amount of energy, the melt pool having a width transverse to the weld direction. Further, the process includes applying a second amount of energy to the substrate that extends outside the width of the melt pool at a trailing edge of the melt pool, which second amount of energy causes, relative to a process without application of the second amount of energy: broadening of the width of the melt pool at the trailing edge of the melt pool as the melt pool advances in the weld direction; and reducing segregation of artifacts and stress concentration along a centerline of the width.

Abstract: An object is to respectively provide excitations light from a plurality of light sources to an odd number of fiber pairs. Optical amplifiers are disposed in three fiber pairs including two optical fibers through which optical signals are transmitted, respectively. The optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. An optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. In optical multiplexers/demultiplexers, one input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, the other input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, one output is alternatively connected to one optical fiber of any one of the three pairs, and the other output is alternatively connected to the other optical fiber of any one of the three pairs.

Abstract: There is provided an optical axis alignment mechanism between the laser oscillator and the optical fiber. The laser oscillator emits laser light, which then emerges from the emission end of the optical fiber via the axis alignment mechanism. Part of the laser light is received on the light-receiving surface of the CCD camera of a laser light evaluator. Thus, the laser light evaluator acquires a light intensity distribution. The light intensity distribution is used by the optical axis alignment mechanism to align the axis of the laser oscillator with the axis of the optical fiber.

Abstract: An optical transceiver that is hot-pluggable to an external device includes: an IC-TROSA including first to third internal fibers extending from a first surface of a package on a side opposite to the device in the first direction; a first substrate on which the IC-TROSA is mounted; a second substrate electrically connected to a light source and the first substrate and to which the light source is attached to generate reference light; a first sleeve provided on the second internal fiber; a second sleeve provided on the third internal fiber; and a fiber tray in which the substrates are mounted in an upper portion and the fibers are housed in a lower portion by being bent greater than a predetermined radius of curvature. The second substrate is arranged between the first and second sleeves and the first substrate in the first direction.

Abstract: Some embodiments include a MEMS apparatus configured to redirect light in a LiDAR system and includes a support frame and a plurality of mirror elements disposed in a linear array within the support frame including a first mirror element and a second mirror element. Each of the plurality of mirror elements can be rotatable on a rotational axis that is perpendicular to a line defined by the linear array of the plurality of mirror elements and bisects the corresponding mirror element into a first portion and a second portion. The apparatus can include a coupling element having a distal end physically coupled to a first portion of the first mirror element and a proximal end physically coupled to a second portion of the second mirror element such that a rotation of the first mirror element causes a synchronous and equal rotation of the second mirror element.

Abstract: An optical fiber amplifier comprising a first optical fiber, a second optical fiber, a third optical fiber, and an excitation light source, is disclosed. Each optical fiber has cores and a cladding surrounding the cores. The third optical fiber transmits excitation light used for signal amplification in the second optical fiber. A rare-earth element is doped to the second optical fiber that amplifies an optical signal propagating therein by the excitation light. The third optical fiber includes a reduced-diameter portion. A distance between the cores of the third optical fiber in the reduced-diameter portion is shorter than a distance between the cores in other portion of the third optical fiber, and the excitation light entering from the excitation light source to one of the cores of the third optical fiber is mode-coupled with another core of the third optical fiber to distribute the excitation light in the reduced-diameter portion.

Abstract: In a pluggable optical module, to easily and compactly house an optical fiber for connecting optical components in a housing in which a plurality of optical components are mounted. A pluggable optical module includes a first optical fiber housing unit a second optical fiber housing unit, and a housing. The first optical fiber housing unit can house a first optical fiber connected to a first optical component. The second optical fiber housing unit can house a second optical fiber connected to a second optical component. The housing can house the first optical fiber housing unit and the second optical fiber housing unit. The pluggable optical module is configured to be capable of being inserted into and removed from an optical communication apparatus and the housing constitutes an outer shape of the pluggable optical module.

Abstract: An apparatus includes a device interface system having a first connector and second connector, each with a respective optical signal path arrangement operatively aligned when the two connectors are in a connected position. The operative alignment allows a base optical signal to be transmitted from the first connector to the second connector. An optical signal modification arrangement is included in the second connector and is operable to provide a predefined modification to the base optical signal to result in an optical ID signal that is transmitted back to the first connector. An identification processing unit associated with the first connector receives an ID input signal corresponding to the optical ID signal and produces an identification output responsive to the ID input signal.

Abstract: An optical fiber comprising: a core having an outer radius r1; a cladding having an outer radius r4?31 microns; a primary coating surrounding the cladding having an outer radius r5, a thickness tp>10 microns, in situ modulus EP of 0.5 MPa or less, and a spring constant ?P<1 MPa, where ?P=2EP r4/tP; and a secondary coating surrounding said primary coating, the secondary coating having an outer radius r6, a thickness tS=r6-r5, in situ modulus ES of 1200 MPa or greater; tS greater than 9.5 microns, wherein r6 is 50 to 67.5 microns. The fiber has a mode field diameter MFD greater than 8.2 microns at 1310 nm; a fiber cutoff wavelength of less than 1310 nm; and a bend loss at a wavelength of 1550 nm, when wrapped around a mandrel having a diameter of 10 mm, of less than 1.0 dB/turn.

Abstract: An optical fiber comprising: a core having an outer radius r1; a cladding having an outer radius r4<45 microns; a primary coating surrounding the cladding and having an outer radius r5 and a thickness tp>8 microns, the primary coating having in situ modulus EP of 0.35 MPa or less and a spring constant ?P<1.6 MPa, where ?P=2EP r4/tP; and a secondary coating surrounding said primary coating, the secondary coating having an outer radius r6, a thickness tS=r6?r5, in situ modulus ES of 1200 MPa or greater, wherein >10 microns and r6?85 microns. The fiber has a mode field diameter MFD greater than 8.2 microns at 1310 nm; a cutoff wavelength of less than 1310 nm; and a bend loss at a wavelength of 1550 nm, when wrapped around a mandrel having a diameter of 10 mm, of less than 1.0 dB/turn.

Abstract: Apparatus for optically isolating a laser (1) from external reflections, which apparatus comprises a mode filter (19) and a first optical fibre (1), wherein: the first optical fibre (1) is a multimode optical fibre that supports a fundamental mode (3) and at least one higher order mode (4); the mode filter (19) is defined by an optical attenuation which is higher for the higher order mode (4) than for the fundamental mode (3); the mode filter (19) is configured to pass the fundamental mode (3) into the first optical fibre (1); and the apparatus being characterized in that: the first optical fibre (1) comprises a long period grating (10); and the long period grating (10) is defined by a period (13) selected to couple the fundamental mode (3) to the higher order mode (4) of the first optical fibre (1); whereby if the fundamental mode (3) and the higher order mode (4) are reflected back into the first optical fibre (1) as back-reflected fundamental and higher order modes (25), (26), then the mode filter (19) opt

Abstract: Some embodiments include a MEMS apparatus configured to redirect light in a LiDAR system and includes a support frame and a plurality of mirror elements disposed in a linear array within the support frame including a first mirror element and a second mirror element. Each of the plurality of mirror elements can be rotatable on a rotational axis that is perpendicular to a line defined by the linear array of the plurality of mirror elements and bisects the corresponding mirror element into a first portion and a second portion. The apparatus can include a coupling element having a distal end physically coupled to a first portion of the first mirror element and a proximal end physically coupled to a second portion of the second mirror element such that a rotation of the first mirror element causes a synchronous and equal rotation of the second mirror element.

Abstract: A fiber amplifier system including an optical component responsive to a seed beam and causing amplitude modulation that creates a non-uniform spectral transmission having peaks and nulls, and an actuator operable to shift the spectral transmission. The system further includes a fiber amplifier responsive to the seed beam and generating an amplified output beam and a beam sampler responsive to the output beam that provides a sample beam. A detector detects power fluctuations in the sample beam caused by the amplitude modulation, and generates a control metric identifying a magnitude of the fluctuations. A controller uses the control metric to control the actuator to cause it to make adjustments to the seed beam or to the optical component to cause the spectral transmission caused by the optical component to shift so that the peaks or nulls of the spectral transmission align with a center frequency of the seed beam.

Abstract: A fiber amplifier system including a plurality of optical components in an amplification chain that are responsive to a seed beam and that cause frequency modulation (FM) to amplitude modulation (AM) conversion to the seed beam that creates a non-uniform spectral transmission having a transmission function, where one of the optical components is a fiber amplifier generating an amplified output beam. A programmable spectral filter is controlled to pre-distort the seed beam by applying an inverse of the transmission function that creates a net uniform transmission function by equalizing a net spectral transmission profile of the seed beam at an end of the amplification chain to reduce the amplitude modulation.

Abstract: A nonlinear fiber interferometer is disclosed suitable for fiber sensor and other applications. A first nonlinear fiber section amplifies probe and conjugate sidebands of a pump through four-wave mixing. A second section introduces a phase shift to be measured, for example from a sensor. A third nonlinear fiber section amplifies with phase-sensitive gain to increase signal-to-noise ratio. Based on phase-sensitive output power of probe and/or conjugate components, the phase shift can be measured. Superior performance can be obtained by balancing gain between the (first and third) nonlinear sections. Non-fiber, for example photonic integrated circuit, embodiments are disclosed. Differential sensing, alternative detection schemes, sensing applications, associated methods, and other variations are disclosed.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for optical communications. In one aspect, an optical amplifier includes an input port, a wavelength division multiplexing fiber coupled to a pump source and to a bar-cross switch, a first gain stage optically coupled between a first port of the bar-cross switch and to an output port, the first gain stage including a first gain flattening filter, and a secondary gain stage optically coupled between a second port and a third port of the bar-cross switch, the secondary gain stage including a second gain flattening filter. When in a bar-state of the bar-cross switch, the secondary gain stage is bypassed. And when in a cross-state of the bar-cross switch, the secondary gain stage and the first gain stage are applied to an input light beam.

Abstract: Fiber lasers and methods are provided, in which the modal instability threshold is raised to provide more laser power. Fiber lasers comprise an active optical fiber having at least one absorption peak wavelength (?peak) and capable of supporting more than a fundamental mode during operation, and a plurality of pump diodes connected to deliver radiation emitted thereby into the optical fiber. At least one of the pump diodes is a wavelength-locked (WL) diode and at least one of the pump diodes is configured to deliver radiation at at least ???(not necessarily the same diode(s)). The pump diodes may comprise any of WL diode(s) at ???peak, WL diode(s) at ?=?peak and non-WL diode(s). Pumping radiation off the fiber's absorption peak increases the modal instability threshold, most likely by reducing the temperature gradient in the active fiber at the fiber pump entrance point and along the fiber.

Abstract: A low loss high extinction ratio on-chip polarizer is disclosed. The polarizer is formed of a mode convertor followed by a mode squeezer and a dump waveguide, and may be configured to pass a desired waveguide mode and reject undesired modes. An embodiment is described that transmits a TE0 mode while blocking a TM0 mode by converting it into a higher-order TEn mode in a waveguide taper, squeezing out the TEn mode in a second waveguide taper to lessen its confinement, and then dumping the TEn mode in a waveguide bend that is configured to pass the TE0 mode.

Abstract: A pulse light source device (100) for creating fs output laser pulses (1, 1.1, 1.2, 1.3) having CEP stability comprises a pulse source device (10) creating primary ps laser pulses, a first beam splitting device (13) splitting the primary ps laser pulses to first ps laser pulses (2.1) and second ps laser pulses (2.2), a pulse shortening device (20) creating sub-ps laser pulses (3) by shortening and spectrally broadening the first ps laser pulses (2.1), a primary supercontinuum generation device (30) creating primary fs laser pulses (4), a pulse stretcher device (40) creating stretched ps laser pulses (5, 5.1) by stretching the primary fs laser pulses (4), a optical parametric chirped-pulse amplification device (51) creating amplified ps laser pulses (6, 6.1) on the basis of the stretched ps laser pulses (5, 5.1) and the second ps laser pulses (2.2); a phase stabilization device (61) creating CEP stable ps laser pulses (7, 7.1) by difference frequency generation of the amplified ps laser pulses (6, 6.

Abstract: A data center includes a wavelength source, a first optical component, a first communications device, and a second communications device. The wavelength source is configured to generate an N-wavelength laser beam. The first port of the first optical component is configured to receive an M-wavelength laser beam from the wavelength source. The second port of the first optical component is configured to send the M-wavelength laser beam to the first communications device. The M-wavelength laser beam includes at least a first-wavelength laser beam. The second port of the first optical component is further configured to receive a modulated first optical signal from the first communications device, the modulated first optical signal is obtained after the first communications device modulates a service signal onto the first-wavelength laser beam. The third port of the first optical component is configured to send the modulated first optical signal to the second communications device.

Abstract: One example includes an optical fiber device. The device includes an optical fiber core that extends axially along a length of the optical fiber device and an optical fiber cladding that surrounds the optical fiber core and extends axially along a length of the optical fiber device. The device also includes a polymer inner jacket that surrounds the optical fiber cladding and extends axially along a length of the optical fiber device. The device further includes a thermally-conductive outer jacket that surrounds the polymer inner jacket and extends axially along a length of the optical fiber device.

Abstract: A transceiver having an improved transmitter optical signal to noise ratio, and methods of making and using the same.

Abstract: Aspects are generally directed to receivers and methods for actively demodulating optical signals. In one example, a receiver includes an optical resonator to receive an optical signal, the optical resonator including an active optical medium interposed between first and second semi-reflective surfaces, where the active optical medium is configured to accumulate resonant optical signal energy inside the optical resonator based on the received optical signal, the second semi-reflective surface is positioned to emit output optical signal energy, and the optical resonator is configured to disturb the output optical signal energy in response to a variation in the received optical signal. The receiver may further include a detector configured to detect the disturbance in the output optical signal energy, and a pump source coupled to the active optical medium to excite the active optical medium to generate an optical gain in the received optical signal.

Abstract: Embodiments of the disclosure relate to reducing out-of-channel noise in a wireless distribution system (WDS). A digital filter in a remote unit is configured to suppress out-of-channel noise in a downlink digital communications signal based on at least one filter configuration parameter received from a control circuit. The control circuit is configured to determine the filter configuration parameter based on physical characteristics of the downlink digital communications signal. By suppressing the out-of-channel noise of the downlink digital communications signal, it is possible to provide a downlink RF communications signal communicated from the remote unit that complies with a spectrum emission mask (SEM).

Abstract: In an example, a tandem pumped fiber amplifier may include a seed laser, one or more diode pumps, and a plural core fiber including a first core and a second core, the second core surrounding the first core. The plural core fiber may include a first section to operate as an oscillator and a second different section to operate as a power amplifier. The one or more diode pumps may be optically coupled to the first section of the plural core fiber, and the seed laser may be optically coupled to the first core.

Abstract: Disclosed is a method of Controlling a gain of an optical amplifier comprising a gain medium and at least one pumping device. The method comprises the following steps: determining or predicting a change of input signal power to the amplifier, changing the pump power from an initial pump power level to a new pump power level at a first time instant, the initial pump power level being the pump power level applied to the amplifier prior to the change in input signal power, setting the pump power to a second pump power level at a second time instant, wherein the pump power level is varied in an oscillatory manner for at least one period of time starting at a third time instant and ending at a fourth time instant, wherein said third time instant is identical with or later than said first time instant and said fourth time instant is identical with or earlier than said second time instant.

Abstract: A fiber optic modulator of pump energy comprising a piece of double clad fiber where the inner cladding layer has a changing cross sectional shape and may have a changing cross sectional area along the length of the fiber. The modulator fiber regulates how pump energy in the inner cladding layer is absorbed into the core of the fiber along the length of the fiber. This regulates how heat is generated in the fiber due to absorption into core.

Abstract: Optical amplifier assembly for spatial division multiplexing (SDM) optical communication systems. Each optical amplifier assembly includes a single pump assembly configured for causing amplification of signals traveling on separate fiber paths in different directions. Each fiber path includes a plurality of spatial dimensions. The single pump assembly includes a plurality of pump sources to provide redundancy and the optical amplifier assembly further includes splitters for splitting outputs of the pump sources to amplifiers coupled to the different spatial dimensions. Different modulation formats may be used on the different spatial dimensions with different pump power being provided to each of the modulation formats. Amplifiers with complementary outputs may be coupled to average out gain deviations.

Abstract: A system for predictive maintenance of at least one optical network element in an optical transport network including a power monitor in communication with the at least one optical network element, the power monitor configured to selectively retrieve an actual power level from the optical network element; the power monitor being in communication with a data store having a specified power level for each of the at least one optical network element and an acceptable tolerance, wherein the specified power level includes a low mark and a high mark defining a specified power level range; wherein the power monitor compares the actual power level to the specified power level; and generates a signal if the actual power level is outside of the specified power level range by an amount greater than the acceptable tolerance.

Abstract: An internally switched fiber laser amplifier is disclosed and claimed. The switch is integrated directly into the fiber amplifier, so that the output power from each fiber amplifier can be switched between N selectable output fibers with minimal (approx. 1%) loss. The switch may be a close coupled pump switch, a spherical mirror or a planar mirror. The fiber laser amplifier may switch both pump and source lights, or may switch only the pump light then combine it with the source light before sending it to a gain amplifier.

Abstract: An exemplary embodiment of the disclosure provides a double fiber optic mode adapter including: a fiber core having a variable core diameter; a fiber cladding having a variable cladding size; a first input interface corresponding to a first core diameter and a first cladding size; a second input interface corresponding to a second core diameter and a second cladding size; a thermally-tapered region wherein the variable core diameter of the fiber core transitions from the first core diameter to the second core diameter and the variable cladding size of the fiber cladding transitions from the first cladding size to a third cladding size; and an etched tapered region wherein the variable core diameter of the fiber core is constant and the variable cladding size of the fiber cladding transitions from the third cladding size to the second cladding size.

Abstract: The present disclosure provides an optical amplifier using an optical fiber. The optical fiber includes a single-mode optical fiber in which a plurality of rare earth elements is doped simultaneously; first and second optical fiber gratings disposed at opposite sides of the optical fiber, respectively, and totally reflecting light having a wavelength in a specific range; a pumping light source configured to generate a pumping light to excite rare earth ions in the optical fiber; and an optical coupler connected to the optical fiber and configured to transmit a light signal generated from a light source and the pumping light generated from the pumping light source to the optical fiber. Therefore, it is possible to obtain efficient amplification of a light signal through a simple configuration using the rare earth elements-doped optical fiber.

Abstract: An optical module includes: a bench part including a bench having a principal surface including first and second areas arranged in a direction of a first axis, a semiconductor optical device disposed on the first area, and a lens disposed on the first area; and a cap including a base made of silicon, the cap being disposed on the bench part. The cap has a cavity containing the semiconductor optical device and the lens, and includes a ceiling extending along a first reference plane, a front wall extending from the ceiling along a second reference plane, and a rear wall extending from the ceiling in a direction from the cap to the bench. The semiconductor optical device, the lens and the cap are arranged along an optical reference plane. The second reference plane is inclined with respect to the first reference plane.

Abstract: Ultrashort pulse fiber amplifier having a pulse width from 200 ps to 200 fs comprising a rare earth oxide doped multicomponent glass fibers for laser amplification, including a core and a cladding, the core comprising at least 2 weight percent glass network modifier selected from BaO, CaO, MgO, ZnO, PbO, K2O, Na2O, Li2O, Y2O3, or combinations; wherein the mode of the core is guided with step index difference between the core and the cladding, a numerical aperture of the fiber is between 0.01 and 0.04; core diameter is from 25 to 120 micron, and a length of the gain fiber is shorter than 60 cm.

Abstract: A fiber light source comprises a laser pump configured to generate a pump laser beam at a predetermined wavelength; a first segment of rare earth doped fiber; a second segment of rare earth doped fiber; and an optical coupler coupled to a first end of the first segment and a first end of the second segment. The optical coupler is configured to split the pump laser beam based on a power coupling ratio. The first segment generates a first stimulated emission having a first mean wavelength sensitivity to pump laser power fluctuations and the second segment generates a second stimulated emission having a second mean wavelength sensitivity to pump laser power fluctuations such that a combined stimulated emission is approximately insensitive to pump laser power fluctuations.

Abstract: The invention is an active double-clad fiber comprising the following four layers: a high refractive index small diameter core; an inner annular clad layer doped with active ions surrounding the core; an outer annular clad layer surrounding the inner clad layer; and an annular low refractive index outer coating layer surrounding the outer clad layer. The structure of the fiber of the invention and the properties of the materials of its layers provides high discrimination against higher modes, thereby maintaining single mode operation in laser systems. The diameter of the core of the fiber of the invention is much smaller than the diameter of the large single transverse mode that it guides, thereby allowing guiding and amplification to take place mainly in the inner doped clad layer.

Abstract: An optical receiver includes a light reception element for receiving an optical signal, a bias voltage supply/monitoring circuit for supplying a bias voltage to the light reception element and generating a monitoring voltage indicating magnitude of an output current of the light reception element, and a constant current source. The bias voltage supply/monitoring circuit is supplied with a remaining current obtained by subtracting the output current of the light reception element from an output current of the constant current source. The bias voltage supply/monitoring circuit converts the remaining current to the monitoring voltage.

Abstract: A universal fiber optic connector includes a housing and a fiber attachment element configured to attach an optical fiber in the housing. The attachment element positions the optical fiber such that an end face of the fiber is held within the housing. The fiber end face is positioned such that a beam of light emerging from the fiber end face has a defined wavefront located at a specified interface.

Abstract: An amplifying device includes a light source configured to output excitation light, a depolarizer configured to change a degree of polarization of the excitation light in accordance with a setting, an amplifier configured to execute Raman amplification so as to amplify a polarized multiplexed optical signal by the excitation light of which the degree of the polarization has been changed by the depolarizer, a measurer configured to measure the power of a plurality of polarized light components multiplexed into the polarized multiplexed optical signal subjected to the Raman amplification and amplified by the excitation light, and an adjuster configured to calculate differences between the power of the plurality of polarized light components and adjust the setting of the depolarizer so as to reduce the differences between the power of the plurality of polarized light components.

Abstract: A spacecraft or satellite optical transmission apparatus (10) including an optical fiber (11) and at least one optical pump source (14) operatively coupled to provide pump energy to the optical fiber (11), the optical fiber (11) comprising an active trivalent dopant such as erbium and at least one passive trivalent dopant such as lanthanum. A method for transmitting electromagnetic radiation in a high radiation environment is also disclosed.

Abstract: A method of operating a Tm:doped fiber amplifier including selecting a length of Tm:doped optical fiber to be less than one hundred meters, doping the optical fiber with active ions at a doping level of greater than one percent, optically pumping the doped optical fiber with a first laser beam having a wavelength longer than the wavelength where a maximum absorption cross section is provided by the active ions, and creating a population inversion between two active ion energy levels with the first laser beam, the active ions providing a gain to a second laser beam.

Abstract: The present invention relates to a pulse laser device, and more particularly, to a pulse laser device which can be operated in a burst mode, in which the output of a low-output laser generator is adjusted so as to enable the uniform control of the profile of the peak output of a final output optical pulse train, and in a variable burst mode, in which the profile of the final output optical pulse train can be controlled into an arbitrary waveform.

Abstract: A universal fiber optic connector includes a housing and a fiber attachment element configured to attach an optical fiber in the housing. The attachment element positions the optical fiber such that an end face of the fiber is held within the housing. The fiber end face is positioned such that a beam of light emerging from the fiber end face has a defined wavefront located at a specified interface.

Abstract: A solid photonic band gap fiber includes: a core area located at a central portion of a cross-section with respect to a longitudinal direction of the fiber, the core area being formed of a solid substance having a low refractive index; cladding areas having base portions formed of a solid substance having a low refractive index, the cladding areas surrounding the core area; and a plurality of fine high refractive index scatterers provided in the cladding areas, and disposed in a dispersed manner so as to surround the core area, the number of fine high refractive index scatterers being formed of a solid substance having a high refractive index, wherein in a state that the solid photonic band gap fiber is held at a predetermined bending radius, propagation in a high-order mode is suppressed by using a difference in a bending loss between a fundamental mode and the high-order mode, and only the fundamental mode is substantially propagated, the fundamental mode and the high-order mode being caused by bending.