Abstract: In an optical amplifier of the present invention, an input light is supplied to one end of an optical fiber connected to an output port, and the power of a light In an opposite direction which is input to the output port from the one end of the optical fiber, is measured, thereby obtaining a stimulated Brillouin scattering (SBS) occurrence threshold in the optical fiber based on the measurement result. Then, using the SBS occurrence threshold, a relation been the input light power and an occurrence amount of the self phase modulation (SPM) or the like in the optical fiber is obtained to be reflected on a control of the optical amplifier, so that an occurrence of the SPM or the like in the optical fiber is suppressed.

Abstract: Control of average wavelength-converted power and/or wavelength converted pulse energy is described. One or more seed pulses may be generated and amplified with an optical amplifier to produce one or more amplified pulses. The amplified pulses may be wavelength converted to produce one or more wavelength converted pulses characterized by an average wavelength-converted power or pulse energy. Wavelength-converted power or pulse energy may be controlled by adjusting wavelength conversion efficiency without substantially changing the amplified power or pulse energy. Average wavelength-converted power may be controlled over a time scale comparable to a pulse period of the amplified pulses without adjusting an average power of the amplified pulses over the time scale comparable to a pulse period of the amplified pulses.

Abstract: An optical amplifier is disclosed having a substantially uniform spectral gain. In an exemplary embodiment, the optical amplifier comprises a planar waveguide including a substrate, which includes a region doped with rare earth element. The optical amplifier also comprises an optical fiber including a core doped with the rare earth element. The optical fiber is optically coupled to the planar waveguide.

Abstract: An optical amplifier comprises a printed circuit board (PCB) having at least one support layer of electrically non-conducting material and at least one conductive layer of electrically conducting material, and a foil heater in the form of a conductive track 20 on the PCB. A specified length of erbium optical fibre is wound around an aluminium spool mounted on the PCB and clamped by a clamp with the interposition of a thermal gasket, so that the optical fibre can be heated by the heater. Cutouts are provided in the PCB surrounding the heater to minimise loss of heat from the heater. The form of the heater enables it to be produced during fabrication of the optical fibre without utilising additional costly fabrication steps.

Abstract: A 2-?m fiber Amplified Spontaneous Emission (ASE) source provides a wide emission bandwidth and improved spectral stability/purity for a given output power. The fiber ASE source is formed from a heavy metal oxide multicomponent glass selected from germanate, tellurite and bismuth oxides and doped with high concentrations, 0.5-15 wt. %, thulium oxides (Tm2O3) or 0.1-5 wt% holmium oxides (Ho2O3) or mixtures thereof. The high concentration of thulium dopants provide highly efficient pump absorption and high quantum efficiency. Co-doping of Tm and Ho can broaden the ASE spectrum.

Abstract: A large mode area optical fiber includes a large diameter core (d1 up to 60 ?m), and a first cladding (diameter d2) wherein the difference between refractive index (n1) in the core and the first cladding (n2) is very small (?n<0.002), thus providing a very low numerical aperture core (NA1 between 0.02 and 0.06). The preferred ratio of d2/d1<2. The fiber further has a second cladding, preferably a layer of air holes, having a very low refractive index n3 as compared to the core and first cladding such that the first cladding has a relatively high numerical aperture (NA2>0.4) (n3 is preferably less than 1.3). The small change in refractive index between the core and inner cladding combined with a large change in refractive index between the first cladding and second cladding provides a significantly improved single mode holding waveguide.

Abstract: A small size and high efficiency laser oscillation apparatus capable of obtaining high output and high beam quality laser light is provided. First waveguide (21) (refractive index=n1) for transmitting excitation light, second waveguide (22) composed of core (23) (refractive index=n3) for generating laser light and clad (24) (refractive index=n2) for transmitting the excitation light, and third waveguide (25) (refractive index=n4) including first waveguide 21 and second waveguide 22 are provided. Light amplifying fiber (20), in which the refractive indices are set so as to satisfy the relation: n1<n4<n2<n3, is used and excised by semiconductor lasers (10a) and (10b).

Abstract: The invention includes optical signal conduits having rare earth elements incorporated therein. The optical signal conduits can, for example, contain rare earth elements incorporated within a dielectric material matrix. For instance, erbium or cerium can be within silicon nanocrystals dispersed throughout dielectric material of optical signal conduits. The dielectric material can define a path for the optical signal, and can be wrapped in a sheath which aids in keeping the optical signal along the path. The sheath can include any suitable barrier material, and can, for example, contain one or more metallic materials. The invention also includes methods of forming optical signal conduits, with some of such methods being methods in which the optical signal conduits are formed to be part of semiconductor constructions.

Abstract: A laser apparatus including a laser generating portion that generates pulse light having a single wavelength within a range from an infrared band to a visible band. An optical amplifier is optically connected to the laser generating portion, and includes a plurality of fiber optical amplifiers to amplify the pulse light a plurality of times. A wavelength converting portion is optically connected to the optical amplifier, and includes cylindrical lenses and a plurality of non-linear optical crystals to wavelength-convert the amplified pulse light into ultraviolet light. The amplified pulse light is incident on the cylindrical lenses through one of the plurality of non-linear optical crystals and is incident on a different one of the plurality of non-linear optical crystals from the one non-linear optical crystal through the cylindrical lenses.

Abstract: Provided is a method of making a self-aligned light guide screen. More specifically, in a particular embodiment, fabrication may commence by providing a first ribbon section of light guides with at least one self alignment feature. A second ribbon section of light guides is provided with at least one self alignment feature configured to mate with the at least one self alignment feature of the first ribbon section. The ribbon sections are then stacked, the alignment features aligning the first and second ribbon sections.

Abstract: An optical fiber coil of sub-micron diameter is shown to exhibit self-coupling between adjacent turns so as to form a three-dimensional optical resonator of relatively low loss and high Q. As long as the pitch of the coil and propagating wavelength remain on the same order (or less than) the fiber diameter, resonance may occur. Resonances can be induced by allowing adjacent turns of the coil to touch each other. Optical devices such as resonators and interferometers may then be formed from such “microcoils” that exhibit superior characteristics to conventional planar devices. A method of forming such a microfiber using indirect laser heating is also disclosed.

Abstract: A laser-active optical fiber for a fiber laser or an optical fiber amplifier contains a laser-active fiber core (2) comprising an undoped inner region (22) which is surrounded by an outer region (24) that is doped with a laser-active material. In this manner a high-power laser beam may be generated which has a mode structure, present in the form of a ring mode, which in particular is suitable for laser machining.

Abstract: A large mode area, gain-producing optical fiber is configured to support multiple transverse modes of signal radiation within its core region. The fiber is a hybrid design that includes at least two axial segments having different characteristics. In a first axial segment the transverse refractive index profile inside the core is not radially uniform being characterized by a radial dip in refractive index. The first segment supports more than one transverse mode. In a second axial segment the transverse refractive index profile inside the core is more uniform than that of the first segment. The two segments are adiabatically coupled to one another. Illustratively, the second segment is a terminal portion of the fiber which facilitates coupling to other components. In one embodiment, in the first segment M12>1.0, and in the second segment M22<<M12. In a preferred embodiment, M12>>1.0 and M22˜1.0.

Abstract: The system of a variable lightwave functional apparatus comprising: an acousto-optical modulator for outputting wavelength multiplexed light containing a plurality of pulses having a first wavelength interval; a coupler arranged at an output of said acousto-optical modulator; a polarization branching/coupling device having a first port to a third port, for branching the output form said coupler, which is entered from said first port into the polarization branching/coupling device, to both said second port and said third port; an optical amplifier connected to said second port of said polarization branching/coupling device; and said variable lightwave functional circuit and arranged between said second port of said polarization branching/coupling device and said optical amplifier; wherein: multi-wavelength oscillation light is outputted from said coupler by laser light from said acousto-optical modulator.

Abstract: The system of a variable lightwave functional apparatus comprising: an optical amplifier for outputting wavelength multiplexed light containing a plurality of pulses having a first wavelength interval; a polarization branching/coupling device having a first port to a third port, for branching output from said optical amplifier, which is entered from said first port into the polarization branching/coupling device, to both said second port and said third port; a coupler arranged at the second port of said polarization branching/coupling device; and said variable lightwave functional circuit, and arranged between said third port of said polarization branching/coupling device and said coupler; wherein: said wavelength multiplexed light containing said plural pulses having said first wavelength interval is converted into wavelength multiplexed light containing a plurality of pulses having a second wavelength interval in response to lateral pressure applied to said polarization-maintaining optical fiber, and said c

Abstract: The invention is in the field of distributed Raman amplification for digital and analog transmission applications and other applications, e.g., instrumentation and imaging applications, including HFC-CATV applications. In particular, the invention uses a high power broadband source of amplified spontaneous emission (ASE) as the Raman pump source for improved system performance. The invention also includes methods for constructing such a high-power broadband Raman pump.

Abstract: The device comprises an optical waveguide and an acoustic wave generating device. The waveguide has an optical band gap and a sharp electronic transition (e.g. an excitonic transition) in the band gap, and the acoustic wave generating device generates acoustic waves within the waveguide. Light passing through the waveguide is of a frequency within the band gap of the waveguide and is nearly resonant with the sharp electronic transition. The wave generating device is arranged to generate acoustic waves so as to induce optical band gas in the polariton spectrum, thereby affecting the transmission of the light passing through the waveguide, the transmission of which is thereby affected.

Abstract: Disclosed is a variable lightwave functional circuit comprising: an applying unit for applying lateral pressure; a polarization maintaining optical fiber having a polarization axis, for inducing a polarization mode coupling by applying the lateral pressure to a predetermined position by said applying unit; and a branching/coupling device having a first port to a fourth port, for branching laser light inputted from the first port to both said second port and said third port, and also for projecting laser light inputted from said second port to the fourth port; wherein one end of said polarization maintaining optical fiber is connected to one of said second port and said third port in such a manner that the polarization axis is inclined at a predetermined angle to an axial direction parallel to a branching plane of said branching/coupling device.

Abstract: The present invention provides a polarization dependency-free, gain-saturated high function semiconductor optical amplifier and optical module at industrially low cost. The gist of the present invention is to structurally separate the optical signal propagating waveguide from another optical waveguide which serves as a lasing optical cavity for optical amplification in such a manner that the two optical waveguides are formed in the same plane but not parallel to each other.

Abstract: The invention describes techniques for the control of the spatial as well as spectral beam quality of multi-mode fiber amplification of high peak power pulses as well as using such a configuration to replace the present diode-pumped, Neodynium based sources. Perfect spatial beam-quality can be ensured by exciting the fundamental mode in the multi-mode fibers with appropriate mode-matching optics and techniques. The loss of spatial beam-quality in the multi-mode fibers along the fiber length can be minimized by using multi-mode fibers with large cladding diameters. Near diffraction-limited coherent multi-mode amplifiers can be conveniently cladding pumped, allowing for the generation of high average power. Moreover, the polarization state in the multi-mode fiber amplifiers can be preserved by implementing multi-mode fibers with stress producing regions or elliptical fiber cores These lasers find application as a general replacement of Nd: based lasers, especially Nd:YAG lasers.

Abstract: An apparatus includes a housing, a first connection interface and an optical amplifier. The housing receives a fiber optic line and an electrical line. The first connection interface is located at least partially inside the housing and is exposed outside of the housing to couple the fiber optic line and the electrical line to a second connection interface. The optical amplifier is located inside the housing and is coupled to the fiber optic line. The optical amplifier receives power from the electrical line.

Abstract: An optical amplifier and a laser generator based on the fiber side-polished technology having a high pumping efficiency, a low noise figure and a small footprint are provided in this application. The optical amplifier and the laser, which have a very long effective interaction length in conjunction with highly doped Erbium glass attached to its surface and an addition of a slanted fiber grating inscribed in the guiding core at the polished region can spatially separate the signal and pump power to simultaneously improve the pumping efficiency and optimize the penetrated depth of the signal evanescent-field. The spontaneous emission is kept from being amplified and therefore a high quality amplified signal is produced.

Abstract: An optically amplifying waveguide that can have a gain having a small wave-length dependency in a wavelength range shorter than the C-band, and the like. The optical amplifier module 1 optically amplifies a signal lightwave that has a wavelength lying in a wavelength range of 1,490 to 1,530 nm and that has entered an input connector 11 to output the optically amplified signal lightwave from an output connector 12. An optical isolator 21, a WDM coupler 31, an Er-doped optical fiber (EDF) 50, a WDM coupler 32, and an optical isolator 22 are provided in this order on a signal lightwave-transmitting path from the input connector 11 to the output connector 12. A pump source 41 connected to the WDM coupler 31 and a pump source 42 connected to the WDM coupler 32 are also provided. In the EDF 50, at least one of the stimulated-emission cross section and the absorption cross section assumes a maximum value at the shorter-wavelength side of a peak at a wavelength range of 1.53 ?m.

Abstract: Single transverse mode fiber amplifier and laser operation is obtained with a multi-mode signal core surrounded by cladding containing irregular microstructuring that causes loss in all of the core modes except the fundamental while maintaining robust guiding of the fundamental mode resulting in higher fiber laser power capacity.

Abstract: The specification describes an optical fiber device wherein a LOM is converted to an HOM prior to entering the gain section. The gain section is a few mode fiber that supports the HOM. The output from the gain section, i.e. the HOM, may be utilized as is, or converted back to the LOM. With suitable design of the few mode fiber in the gain section of the device, the effective area, Aeff, may be greater than 1600 ?m2. The large mode separation in the gain section reduces mode coupling, allowing greater design freedom and reducing the bend sensitivity of the optical fiber.

Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.

Abstract: A module for amplifying a signal light with a remote excitation-light, includes (a) a first optical input/output line through which a signal light is transmitted, (b) a second optical input/output line through which a signal light is transmitted, (c) an optical amplifier which amplifies a signal light on receipt of an excitation light transmitted through the first or second optical input/output line, (d) a bypass circuit which allows the signal light to bypass the optical amplifier, (e) a first optical connector which optically connects the first optical input/output line to the optical amplifier, and further optically connects the first optical input/output line to the bypass circuit, and (f) a second optical connector which optically connects the second optical input/output line to the optical amplifier, and further optically connects the second optical input/output line to the bypass circuit.

Abstract: There is provided a broadly tunable laser beam generator serving as a laser beam source which utilizes a nonlinear optical effect of a silica (glass) fiber and which is broadly tunable in the near-infrared region, having ultra-broad tunability which has not been easily achieved by known tunable lasers, and generating coherent light which can be continuously swept over the entire wavelength region with a simple mechanical operation of a single wavelength selecting element and which is emitted in a constant direction independent of its wavelength. The laser beam source which utilizes a nonlinear optical effect of a silica optical fiber (8) and which is broadly tunable in the near-infrared region has ultra-broad tunability and generates coherent light which can be continuously swept over the entire wavelength region with a single wavelength selecting element (10).

Abstract: An optical transmission system which permits transmission distance to be prolonged without using repeaters and yet ensures economical, high-quality optical transmission. A branch station performs non-repeated communication with an optical branching point and includes a light pumping section for causing pump light to enter an optical fiber through which a branched, receiving optical signal flows, to perform optical amplification by using the fiber as an amplification medium. An optical branching device includes an optical amplification section and an optical branching section. The optical amplification section redirects the pump light originated from the branch station and propagated through a line to the paired line through which an optical signal transmitted from the branch station flows, to excite an amplification medium inserted in the paired line and doped with active material for optical amplification and thereby amplify power of the optical signal transmitted from the branch station.

Abstract: An ultra-low RIN band fiber light source is provided. In one embodiment, the fiber light source includes at least one segment of optical fiber, one or more pump lasers, at least two wavelength division multiplexers and a reflective device. Each pump is adapted to output a power signal having a select wavelength and a select power level. Each wavelength division multiplexer is adapted to couple an associated power signal from at least one of the one or more pumps into the at least one segment of optical fiber to generate amplified spontaneous emission (ASE) signals having select parameters in the at least one segment of optical fiber. The reflective device is coupled to an end of the at least one segment of optical fiber and is adapted to reflect back a portion of the ASE signals.

Abstract: A dispersion compensator and method of dispersion compensation in which an input light is converted to a selected second wavelength, the converted light beam having the second wavelength is dispersion compensated in an amount dependent upon the second wavelength, and the compensated light beam having the second wavelength is converted to the first wavelength.

Abstract: The present invention relates to all optical choppers for shaping and reshaping. A chopper according to some embodiments of the invention may include a threshold device having an input terminal for receiving an optical input signal and an output terminal for emitting an optical output signal in response to a part of the input signal having intensity above a threshold level of the chopping device, wherein the output signal is narrower than the input signal. In other embodiments the device may include a first splitting device having at least first, second and third terminals, and at least one nonlinear element, wherein the second and third terminals form an optical loop including at least one nonlinear element displaced from the center of the optical loop, wherein the splitting device is arranged to receive an input signal for producing a first output signal that is narrower than the input signal. In further embodiments the optical loop includes at least one more attenuator.

Abstract: Characteristics are rendered variable and high-functional by using the side-pressure inductive polarization mode coupling of a PMF to thereby change the position and magnitude of a side pressure. An input light is incident via a polarizer (2), and an outgoing light is output via the PMF (1) and another polarizer (3). Light may enter and go out in an opposite way. The PMF (1) has two polarization axes orthogonal to each other, and the polarization axis of the polarizer (2) is coupled so as to agree with one end of the polarization axis of the PMF (1). The polarization axis of the polarizer (3) is coupled so as to agree with one end of the polarization axis of the PMF (1). The PMF (1) induces polarization mode coupling when a polarization light tilted a specified angle with respect to the polarization axis is incident to apply a side pressure to the PMF (1).

Abstract: Systems and methods for controlling temperature in an optical amplification system are provided. An optical amplification system comprises a pump laser, a multiplexer, an optical fiber, a temperature control device, and processing circuitry. The pump laser generates an optical pump signal. The multiplexer multiplexes the optical pump signal and an input optical signal to generate a multiplexed optical signal. The optical fiber receives the multiplexed optical signal. The temperature control device controls temperature within the optical amplification system based on a control signal. The processing circuitry determines whether to adjust the temperature of the optical amplification system and generates the control signal based on this determination.

Abstract: An object of the invention is to provide an optical multiplexing method and an optical multiplexer, capable of fixing lights of different wavelengths at required wavelengths to stably multiplex them with a simple optical circuit configuration. To this end, in the present optical multiplexer, there is provided a tilted FBG, which is formed on an optical fiber through which a first light is propagated, with a grating direction thereof being tilted to an axial direction of the optical fiber, and has the sufficiently high reflectance to a second light (multiplexed light) of a wavelength different from that of the first light. The multiplexed light emitted from a light source is irradiated to the tilted FBG, via a free space from an angle direction determined according to a grating pitch of the tilted FBG and the wavelength of the multiplexed light, to be coupled within the optical fiber.

Abstract: A method of irradiating ultraviolet light onto an object. The method includes generating pulse light having a single wavelength within a range from 1.51 ?m to 1.59 ?m from a laser generating portion, amplifying the pulse light plural times with an optical amplifier that includes a plurality of fiber optical amplifiers, wavelength-converting the amplified pulse light into ultraviolet light with a wavelength converting portion that includes a plurality of non-linear optical crystals, and irradiating the ultraviolet light onto the object through an optical system.

Abstract: An optically active linear single polarization device includes a linearly birefringent and linearly dichroic optical waveguide (30) for propagating light and having single polarization wavelength range (48). A plurality of active dopants are disposed in a portion (34) of the linearly birefringent and linearly dichroic optical waveguide (30) for providing operation of the waveguide in an operating wavelength range (650) for overlapping the single polarization wavelength range (48).

Abstract: A dual-port broadband light source is disclosed. In the dual-port broadband light source, a first beam splitter splits a first ASE at a first ratio into the second and third light paths and outputs the first ASE received from the second light path to the first light path. A second beam splitter splits a second ASE at a second ratio into the second and fourth light sources and outputs the second ASE received from the second light path to the first light path. A first reflector reflects input first and second ASEs in the first light path, and a second reflector reflects input first and second ASEs in the second light path. A first gain medium generates the first ASE between the first reflector and the first beam splitter, and a second gain medium generates the second ASE between the first reflector and the second beam splitter.

Abstract: An optical amplifier (200) splits an optical signal into two signals (210, 212). A first amplifier section (202) receives the first signal (210). The first amplifier section (202) includes a first optical fiber (220), having a first input, for generating a first output power (230), and a first pump source (222) is coupled to the first input, for supplying a first energy amount to the first optical fiber (220). The optical amplifier (200) also includes a second amplifier section (204) to receive the second signal (212), which is arranged in parallel to, and under common control with, the first amplifier section (202). The second amplifier section (204) includes a second optical fiber (240), having a second input, for generating a second output power (250), and a second pump source (232) is coupled to the second input, for supplying a second energy amount to the second optical fiber (240). A total power (280) of the first output power (230) and the second output power (250) is at least about 600 mill Watts.

Abstract: A rare-earth-doped optical fiber comprises a silica core region doped with a rare earth element and a cladding region adjacent the core region, characterized in that the core region is also doped with aluminum (Al) and fluorine (F). The presence of small amounts of F are effective to lower the refractive index, and hence the NA, of the core region even in the presence of significant amounts of Al (e.g., >8 mol %). Thus, the fiber has both a relatively flat gain spectrum and a low NA (e.g., <0.20). Also described are optical amplifiers that incorporate such fibers. Preferably the rare earth composition of the core includes at least erbium, and the core is also doped with germanium.

Abstract: A Raman amplifier having a microstructured fiber and at least one pump laser, optically connected to one end of the microstructured fiber. The pump laser is adapted for emitting a pump radiation at a wavelength ?p, and the microstructured fiber has a silica-based core surrounded by a plurality of capillary voids extending in the axial direction of the fiber. The core of microstructured fiber has at least one dopant added to silica, the dopant being suitable for enhancing Raman effect.

Abstract: The present invention relates to an analog optical transmission system having a construction for expanding an analog transmittable distance. The analog optical transmission system includes: a light transmitter outputting analog optical signals such as image signals modulated in accordance with electrical signals multiplexed on a frequency domain; a transmission line including a SMF of 20 km or less in the total length; and a light receiver. A dispersion compensating fiber compensating for the chromatic dispersion of the transmission line is arranged on the transmission line, and the dispersion compensating fiber satisfies one of the first condition that the chromatic dispersion is set at ?250 ps/nm/km or less and a length is set at 1.1 km or less, and the condition that the chromatic dispersion is set at ?330 ps/nm/km or less and a length is set at 1.2 km or less. Optical suppressing devices reducing the MPI noise are arranged at the end portion of the dispersion compensating fiber.

Abstract: A broadband light source includes an optical amplifier having amplifying mediums connected in series outputs an amplified spontaneous emission light over a wide wavelength range forward or backward. A circulator connected in series to the optical amplifier returns back to the amplifier spontaneous emission light outputted backwardly from the amplifier. A first pumping means located between the circulator and the optical amplifier pumps a pumping light to the optical amplifier, and a second pumping means located after the optical amplifier pumps a pumping light to the optical amplifier.

Abstract: An input monitoring system is provided in an optical amplifying repeater to monitor a level of an optical input signal. A monitored level of the optical input signal is used to detect a fault on an optical transmission path or to control a bias current for a laser diode which emits and supplies an exciting signal for exciting an optical fiber amplifier. To accurately monitor a level of the optical input signal, the input monitoring system comprises an input terminal supplied with the optical input signal, an optical fiber amplifier for amplifying the optical input signal, a first photo diode for detecting and outputting an electric signal corresponding a level of the optical input signal, and an optical switch operatively connected to the input terminal, the optical fiber amplifier and first photo diode for switching the optical input signal alternatively into the optical fiber amplifier and the first photo diode.

Abstract: Systems, apparatuses, and methods are disclosed that include network control architectures that provide for distributed control of the optical component work functions and network management. The distribution of the work function control in the network element provides for a hierarchical division of work function responsibilities. The hierarchical division provides for streamlined and specically tailored control structures that greatly increases the reliability of the network management system.

Abstract: An optical amplifier system and method are disclosed for amplifying CWDM channels. The optical amplifier system includes a first optical amplifier that includes a fluoride-based optical fiber of a first length and a second optical amplifier that includes a fluoride-based optical fiber of a second length. The first length of fluoride-based optical fiber in the first optical amplifier is different than the second length of fluoride-based optical fiber in the second optical amplifier. When in operation, the first optical amplifier receives optical signals for CWDM channels and amplifies the CWDM channels. The second optical amplifier then receives the optical signals and amplifies the CWDM channels. Between the first optical amplifier and the second optical amplifier, the optical amplifier system generates a continuous gain bandwidth over the CWDM channels.

Abstract: The present invention provides devices and methods for dispersion compensation. According to one embodiment of the invention, a dispersion compensating device includes a negative dispersion fiber having an input configured to receive the optical signal, the negative dispersion fiber having a length and dispersion sufficient to remove any positive chirp from each wavelength channel of the optical signal, thereby outputting a negatively chirped optical signal; an amplifying device configured to amplify the negatively chirped optical signal; and a nonlinear positive dispersion fiber configured to receive the negatively chirped optical signal. The devices of the present invention provide broadband compensation for a systems having a wide range of variable residual dispersions.

Abstract: The present invention provides the following designing method: in a laser diode module or a depolarized laser diode module which has one laser diode and one polarization maintaining fiber connected to the output side thereof, the length of the polarization maintaining fiber is a value obtained by calculation of equation 37 with use of a longitudinal mode spacing ??output light from the Fabry Perot (FP) laser diode, an oscillating center wavelength ?0 of the laser light, a beat length LBeat 1 of the polarization maintaining fiber and an optical wavelength ?Beat used in the measurement of the LBeat 1.

Abstract: Provided is a millimeter wave oscillator for generating a high frequency signal required in wireless communication. The millimeter wave oscillator uses an overwritten fiber Bragg grating and a light detector such that two wavelengths in a certain phase relationship are produced to generate a signal of a millimeter wave band with a high frequency, whereby a light source is readily obtained without signal processing for phase lock.

Abstract: Long-period fiber gratings are placed in a predetermined pattern along a double-clad optical fiber having an outer cladding, an inner cladding and a core. The core is doped with an optically active material such as, for example, a rare earth ion or other laser ion. The long-period fiber gratings couple light between a mode of the inner cladding and a mode of the core. As a consequence of increased coupling into the core resulting from the use of long-period fiber gratings, the length of double-clad optical fiber needed to transfer light between the inner cladding and the core is reduced.