471 results about "Optical fibre amplifiers" patented technology

One or more single mode few-moded or multimode fibers are incorporated into a bundle to carry input to a fiber amplifier or output from a fiber amplifier or a fiber laser. The input is at the signal wavelength, which is the wavelength where amplification or lasing occurs. Each of the fibers in the bundle is cleaved individually or as a group and fiber ends are aligned in the same plane. The fiber amplifier or fiber laser may include a double clad fiber and the other fibers of the bundle couple light for cladding pumping. The device may also include a mode filter for controlling the output mode.

The inventive optical fiber coupler array is capable of providing a low loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Alternatively, the novel coupler array may be configured for utilization with at least one of an optical fiber amplifier and an optical fiber laser.

The effect of bending is anticipated in an optical fiber design, so that resonant coupling remains an effective strategy for suppressing HOMs. The index profile of the fiber and its bend radius are configured so that there is selective resonant coupling of at least one HOM, but not the fundamental mode, in the bent segment of the fiber. In an illustrative embodiment, the bend radius (or predetermined range of bend radii) of an optical fiber is known a priori. The core and cladding regions are configured to support (guide) the propagation of signal light in a fundamental transverse mode and at least one higher-order transverse mode in the core region. The cladding region includes an outer cladding region and an annular trench region. The trench region includes at least one axially extending, raised-index pedestal (waveguide) region having a refractive index higher than that of the outer cladding region. Within at least the bent segment the at least one pedestal region is configured (i) to support the propagation of at least one transverse mode and (ii) to resonantly couple at least one of the higher-order transverse modes (HOMs) of the core region to at least one transverse mode (e.g., the fundamental mode) of the pedestal region when the fiber is bent to a radius within the predetermined range of radii. In effect, the pedestal regions are configured so that the fiber is pre-compensated for the effect of bending; that is, an uncompensated bent fiber segment suffers high fundamental mode loss due to resonant coupling, whereas the pre-compensated bent fiber segment selectively couples any unwanted HOM from the core region into the pedestal region. In a preferred embodiment, the optical fiber is a LMA fiber incorporated in an optical fiber amplifier or laser package.

The present invention relates to an optical component comprising an acceptance fibre, e.g. a photonic crystal fibre, for propagation of pump and signal light, a number of pump delivery fibres and a reflector element that reflects pump light from the pump delivery fibres into the acceptance fibre. It is an object of the invention to provide a fibre coupler for coupling two or more light sources into a multi-clad (e.g. double clad) optical fibre, which has practical advantages with respect to handling, loss and back reflection. An object of the invention is achieved by an optical component comprising a) a first fibre having a pump core with an NA1, and a first fibre end; b) a number of second fibres surrounding said pump core of said first fibre, at least one of said second fibres has a pump core with an NA2 that is smaller than NA1, said number of second fibres each having a second fibre end; and c) a reflector element comprising an end-facet with a predetermined profile for reflecting light from at least one of said second fibre ends into the pump core of said first fibre. The invention further relates to articles comprising the optical component (e.g. a laser or amplifier), to methods of its production and use. The invention further relates to a rod-type optical fibre with optimized stiffness to volume ratio. The invention may e.g. be useful in applications such as fibre lasers or amplifiers, where light can be coupled efficiently from pump sources to an acceptance fibre, e.g. a double clad fibre, using the optical component. The invention specifically addresses optical fibre amplifiers where pump light and signal light are propagating in different directions (counter-propagating pump) within a double-clad optical fibre.

An optical fiber amplifier utilizing a phosphate glass optical fiber highly doped with rare-earth ions such as erbium to exhibit high gain per unit length, enabling the use of short fiber strands to achieve the needed gain in practical fiber optical communication networks. The high-gain phosphate optical glass fiber amplifiers are integrated onto substrates to form an integrated optics amplifier module. An optical pump such as a semiconductor laser of suitable wavelength is used to promote gain inversion of erbium ions and ultimately provide power amplification of a given input signal. Gain inversion is enhanced in the erbium doped phosphate glass fiber by co-doping with ytterbium. A phosphate fiber amplifier or an integrated optics amplifier module utilizing this power amplification can be combined with other components such as splitters, combiners, modulators, or arrayed waveguide gratings to form lossless or amplified components that do not suffer from insertion loss when added to an optical network. The fiber amplifier can be a single fiber or an array of fibers. Further, the phosphate glass fibers can be designed with a temperature coefficient of refractive index close to zero enabling proper mode performance as ambient temperatures or induced heating changes the temperature of the phosphate glass fiber. Large core 50-100 .mu.m fibers can be used for fiber amplifiers. The phosphate glass composition includes erbium concentrations of at least 1.5 weight percentage, preferably further including ytterbium at 1.5 weight percentage, or greater.

An exposure apparatus has a light source comprising a laser device that is small and easy to maintain. The laser device comprises a laser oscillator for generating a single-wavelength laser beam (LB3) within a wavelength range including infrared and visible regions; an optical amplifier (18) for amplifying a laser beam (LB3); and a wavelength converter for converting the amplified laser beam into ultraviolet light using a nonlinear optical crystal. The optical amplifier (18) includes a plurality of stages of optical fiber amplifiers (22, 25) for sequential amplification of the laser beam (LB3), and a narrow-band filter (24A) and an isolator (IS3) arranged between optical fiber amplifiers.

The invention discloses a novel method for realizing spectral combination amplification based on the frequency division multiplexing technology, which comprises the following steps of: (a), pre-amplifying and broadening laser pulse generated by an ultra-short pulse oscillator; (b), segmenting the frequency spectrum of a super-continuous broad-band spectrum into multiplex optical pulses with different central wavelengths; (c), amplifying each optical pulse, outputting a part of amplified seed light to a self-reference zero-frequency detection device by using a splitting slice, and taking a beat frequency signal output by the self-reference zero-frequency detection device as the driving frequency of an acousto-optic frequency shifter after filtering and amplifying; (d), coherently synthesizing amplification pulses output by various multi-stage optical fibre amplifiers through a wavelength division multiplexing beam combiner; and (e), carrying out dispersion compensation and pulse width compression of coherently synthesized pulses by using a compressor so as to obtain ultra-short pulse output with high peak power. According to the invention, the frequency division multiplexing technology and the coherent synthesizing technology are organically combined; therefore, the pulse synchronization problem and the spectrum coherent problem in the ultra-short pulse optical fibre laser coherent synthesizing process are solved.

A laser apparatus that includes a laser light generation section, an optical amplification section, a wavelength conversion section and a suppressing section is provided. The laser light generation section includes a single wavelength oscillatory laser and generates pulsed light having a single wavelength within a wavelength range ranging from about 1.51 to 1.59 μm. The optical amplification section includes an optical fiber amplifier and is optically connected to the laser light generation section to amplify the pulsed light. The wavelength conversion section includes a nonlinear optical crystal and is optically connected to the optical amplification section to perform wavelength conversion of the amplified pulsed light into ultraviolet light. The suppressing section suppresses expansion of a wavelength width of light originated in a nonlinear effect of an optical element between the single wavelength oscillatory laser and the wavelength conversion section.

The invention relates to the technical field of fiber sensing, and especially to a pre-pumped pulse and Gray code based BOTDA instrument. The BOTDA instrument comprises a narrow-linewidth semiconductor sensor, a coupler, a first erbium doped fiber amplifier, a first polarization controller, a single sideband modulator, a microwave source, an optical isolator, a sensing fiber, an optical annular device, a second erbium doped fiber amplifier, a polarization scrambler, an electro-optical intensity modulator, a second polarization controller, an arbitrary waveform generator, an optical filter, a photoelectric detector and a signal collecting and processing system. On the premise that the high spatial resolution of a BOTDA system is maintained, the BOTDA instrument ensures the sensing distance and the measuring precision of the system, and improves the sensing performance of the system.

The invention relates to an optical fiber array phase array deflection transmission system based on SPGD algorithm, belonging to the technical field of photoelectric detection. The system includes a driving and temperature control circuitry, an optical wave phase control system based on SPGD algorithm, a continuous fiber laser, an optical fiber, an electro-optic modulator, a phase modulator, an optical isolator, a continuous fiber amplifier, a collimating beam expander and a sampler. In the invention, the power of N continuous optical fiber lasers can be amplified by using a feedback fine stable driving and temperature control circuit, the N ways of the synthesized light beams can be increased without limit according to the requirement of detection power, At the same time, by using SPGD algorithm , the closed-loop feedback regulation and phase real-time compensation of the phase of the power amplified pulse light changes of N-way can be realized, It can realize the phase locking of theN-way pulsed beam while meeting the beam coherent synthetic deflection under a certain angle. And it can solve the problem of great inertia of traditional mechanical scanning, low sensitivity, closedetection distance and its traditional SPGD method not realizing the deflection of scanning beam.

The invention discloses a high-speed demodulation method for a high-capacity weak grating sensing network. The method comprises the following steps: (1) inscribing a plurality of weak gratings FBGr, FBG1, FBG2, FBG3 and the like in sequence on an optical fiber, wherein the FBGr is taken as a reference grating, and the FBG1, FBG2, FBG3 and the like are divided into m (m is more than or equal to 1) groups of identical weak grating arrays for constructing a sensing network; (2) generating pulse light by using a pulse laser, introducing the pulse light into the reference grating and the sensing network through an optical circulator, returning the reflected signal of each weak grating to the optical circulator, and introducing the reflected signals into an erbium-doped optical fiber amplifier for amplifying; (3) feeding the amplified reflected signals into a dispersion compensation optical fiber, receiving the time of the reflected signal of each weak grating by using a photoelectric detector, and performing signal processing through a high-speed data acquisition system to obtain the wavelength change of each weak grating in the sensing network in order to realize demodulation. A high-speed demodulation device for the high-capacity weak grating sensing network mainly comprises a pulse laser, an optical circulator, an optical fiber inscribed with a plurality of weak grating, am erbium-doped optical fiber amplifier, a dispersion compensation optical fiber, a photoelectric detector and a high-speed data acquisition system.

The invention discloses an all-optical wavelength converting device based on non-linear optical waveguide. The device comprises a first optical coupler, an erbium-doped optical fiber amplifier, a polarization controller, a PPLN waveguide, an optical isolator, a second optical coupler and a pump optical wavelength selector, which are connected in sequence by optical paths in clockwise direction to form an annular cavity laser with the built-in PPLN optical waveguide. The first optical coupler and the second optical coupler respectively provide a signal light input port and a converted idle light output port for the external. The non-linear optical waveguide is the PPLN optical waveguide and the pump optical wavelength selector is a dual wavelength selector or a multiple wavelength selector. The pump light produced by signal light and the inner of the annular cavity by lasing carries out non-linear mutual interaction in the PPLN optical waveguide to generate converted idle light, so as to realize wavelength converting. The device can realize tunable wavelength converting of single-channel to dual-channel and single-channel to multi-channel (broadcasting type) and input and output tunable wavelength converting with the advantages of flexible converting function, compact and easily realizable structure and low cost.

A fiber amplifier having two erbium doped fiber coils and a pump laser diode optically coupled, through a fiber array, to a planar lightwave circuit, is described. A photodetector array, a multiport free-space optical isolator, and a strip of thin-film gain flattening filter are attached to a side surface of the planar lightwave circuit, which has a tunable optical power splitter for variably splitting the optical pump power for the laser diode between the two erbium doped fiber coils, and variable tilters for correcting the gain tilt of the amplifier. The variable splitter and the tilters are thermally tunable Mach-Zehnder interferometers.

A feedback-type optical fiber amplifier using hybrid pumping light beams disclosed, including: an optical line through which an optical signal is propagated; a plurality of rare-earth-doped fibers, doped with a predetermined rare earth ion, being coupled to the optical line in series; a plurality of pumping light sources for outputting pumping light beams having wavelengths different from each other; a plurality of optical coupling means for coupling the pumping light beams to the optical line; and feedback means for dividing the pumping light beam outputted through at least one of the rare-earth-doped fibers, and looping it back to corresponding rare-earth-doped fiber as its input. Therefore, the length of fiber constructing the optical fiber amplifier is reduced, and the amplification efficiency is improved.

An optical fiber can efficiently excite metallic ions by a pump lightwave, and an optical fiber amplifier and an optical fiber laser light source both incorporate the optical fiber. The optical fiber comprises (a) a solid region that has a first region doped with metallic ions and a second region surrounding the first region and that allows a lightwave for exciting the metallic ions to travel in a multiple mode and (b) a third region surrounding the second region and having a plurality of holes stretching along the length of the optical fiber. The optical fiber has a structure in which the first region is supplied with the power of a lightwave that is included in the pump lightwave and that is in a mode having no intensity peak at the center axis of the solid region.

The invention discloses a microwave photonic zero-intermediate-frequency receiving device and method. The method relates to the technical field of microwave and the technical field of optical communication. The method is as shown in the drawings. The device comprises a laser (LD), a polarization multiplexing Mach-Zehnder modulator (PDM-MZM), an erbium-doped optical fibre amplifier (EDFA), a wavelength division multiplexer (WDM), polarization controllers (PCs), a polarization beam splitter (PBS) and balance photoelectric detectors (BPDs). Modulation and polarization multiplexing of radio-frequency (RF) and local oscillator (LO) signals are carried out by utilization of the PDM-MZM; the WDM separates upper and lower optical sidebands; the PCs are respectively utilized for adjusting the polarization states of optical signals; and finally, the two BPDs respectively output I-channel and Q-channel baseband signals. By means of the microwave photonic zero-intermediate-frequency receiving device and method disclosed by the invention, zero-intermediate-frequency receiving is realized through a photonic method; the electronic bottleneck in the traditional electric field technology can be overcome; and the microwave photonic zero-intermediate-frequency receiving device has the advantages of being wide in working band, high in IQ balance degree, inhibited in direct-current offset and even-order distortion, electromagnetic-interference-resistant and the like.

The invention discloses a method and device for monitoring and controlling a high-precision optical fiber optical frequency comb. The method and device are used for monitoring and controlling working conditions of links of the optical fiber optical frequency comb and improving the long-term stability, the operation reliability and the product replicability of the optical fiber optical frequency comb. By means of the device, pulse carrier-envelope phases output by an optical fiber laser oscillator and optical fiber amplifiers in all stages are monitored, transmission and fluctuation of laser phase noise in the power amplification process are observed and controlled, carrier-envelope phase output signals of the main amplifier are negatively fed back to a carrier-envelope phase control unit in the laser oscillator, namely an electronic control polarization controller modulates the pulse polarization evolution process or modulates the pump light strength of the laser oscillator, and stable control over the carrier-envelope phases is achieved. By means of the method and device, the working conditions of the laser oscillator and the amplifiers in all stages can be monitored and controlled in real time, monitoring indexes are timely and comprehensive, and a stable and reliable feedback mechanism is provided.

The invention discloses an optical fiber amplifier dynamic gain slope equalizer and a manufacturing technology thereof. The equalizer comprises an MEMS optical micro mirror driver chip and a double-optical fiber collimator through optical package; the MEMS optical micro mirror driver chip comprises an first optical micro reflecting mirror, a second optical micro reflecting mirror and a micro displacement regulating unit; the micro displacement regulating unit is used for controlling micro displacement motion of the first optical micro reflecting mirror and / or the second optical micro reflecting mirror in the horizontal direction or / and vertical direction, MZI splitting ratio and interference arm phase tuning can be realized, and spectral slope with inputted WDM optical signals can be dynamically controlled. The dynamic gain slope equalizer provided by the invention is manufactured by adopting the MEMS technology, has the advantages of low insertion loss, wide equalized range, small size, quick tuning speed, micro driving power and the like, can be directly integrated in the EDFA for realizing dynamic gain slope equalization, and can also be applied to the problem that signal power in the DWDM channel is not equalized due to transmission optical fiber, an optical fiber dispersion compensation module, optical fiber SRS effect and the like.

The invention relates to an optical fiber amplifier and a production method thereof, as well as an optical fiber communication system, which pertain to the field of optical fiber communication technology. The optical fiber amplifier comprises at least one pump laser, at least one section of gain medium and at least one integrated optical device; wherein the integrated optical device comprises a plurality of light input ports and light output ports, which are directly or indirectly connected with the pump laser or the gain medium. The invention solves the problems of a prior optical fiber amplifier such as a large number of discrete devices and combined devices, and instability in performances and difficulty in compression of the volume due to the large quantity of optical fiber fusion splices. At the same time, the invention reduces the complexity and the cost of the production, and improves the production efficiency of the optical fiber amplifier.

Optical pump modules comprising VCSEL and VCSEL array devices provide high optical power for configuring fiber optic gain systems such as fiber laser and fiber amplifier particularly suited for high power operation. Pump modules may be constructed using two reflector or three reflector VCSEL devices optionally integrated with microlens arrays and other optical components, to couple high power pump beams to a fiber output port. The pump module having a fiber output port is particularly suited to couple light to an inner cladding of a double-clad fiber, often used to configure high power fiber laser and fiber amplifier. The pump modules may be operated in CW, QCW and pulse modes to configure fiber lasers and amplifiers using single end, dual end, and regenerative optical pumping modes. Multiple-pumps may be combined to increase pump power in a modular fashion without significant distortion to signal, particularly for short pulse operation.

Apparatus comprising an optical fibre (1) having a waveguide (2) and at least one stress applying region (3): in which the waveguide (2) is defined by a numerical aperture; the stress applying region (3) has a depressed refractive index; the optical fibre (1) is configured such that the waveguide (2) supports at least two polarised fundamental modes, two polarised first second-order modes, and two polarised second second-order modes; the waveguide (2) comprises a gain medium (4); and the stress applying region (3), the waveguide (2)and the disposition of the gain medium (4) are such as to provide preferential guidance to at least one of the modes at an operating wavelength.

The invention discloses a producing method which is easily implemented and can output stable single-longitudinal-mode multi-wavelength broadband-tunable brillouin laser, and a brillouin laser device. The method uses the brillouin laser device which is composed of an optical passive resonant cavity and an erbium-doped fiber amplifier arranged at the outer part of the optical passive resonant cavity, brillouin stokes light generated in the optical resonant cavity is fed back to the erbium-doped fiber amplifier, and therefore the single-longitudinal-mode multi-wavelength broadband-tunable brillouin laser is obtained. The brillouin laser device comprises the erbium-doped fiber amplifier, a tunable laser device and the optical passive resonant cavity, wherein the erbium-doped fiber amplifier is arranged at the outer part of the optical passive resonant cavity; the tunable laser device is connected with the erbium-doped fiber amplifier through a fiber coupler; and the optical passive resonant cavity is connected with the output end of the erbium-doped fiber amplifier. Meanwhile, the optical passive resonant cavity is connected with the input end of the erbium-doped fiber amplifier through the fiber coupler.

The invention relates to a filter feedback reusable millimeter wave subcarrier light controlled microwave beam forming network, which belongs to the technical field of millimeter wave subcarrier optical controlled microwave beam forming, and is characterized in that a wavelength selecting reusable module transforms wide-spectrum light output by wide-spectrum light source to a comb-like spectrum; the comb-like spectrum is modulated by microwave signals which need to be transmitted, and the comb-like spectrum most energy of which is concentrated in the peak wavelength is formed after dispersive delay and amplification; then an adjustable filter in the wavelength selecting reusable module is utilized for inverse filtering to obtain each required signal; amplification efficiency of an erbium-doped optical fibre amplifier is greatly enhanced, and then the power level of useful spectra of the entire link is enhanced; and compared with that traditional wide-spectrum light passes through the light controlled microwave beam forming network, the invention enhances energy utilization.

The invention relates to s double-clad optical fiber comprising a fiber core and a cladding. The optical fiber is characterized in that the fiber core is a silica-base glass core layer doped with ions, the cladding comprises an inner cladding body and an outer cladding body, the inner cladding body is a total solid silica-base glass layer composed of two doping stress areas with the low refractive index, the doping stress areas are symmetrical about the fiber core, the outer cladding body is an annular silica-base glass layer formed by air holes, the outer cladding body is provided with a supporting layer, the supporting layer is a total solid silica-base glass layer, and the outermost layer of the optical fiber is a coating layer. Special coating with the lower refractive index is needless to serve as the outer cladding body, so that coating cost is greatly reduced. The outer cladding body is silica-base glass with air holes, and is resistant to high temperature, safe, suitable for being used in a high-power optical cable laser and an optical fiber amplifier, and meanwhile suitable for optical fiber preparation in a large mode field area. The double-clad optical fiber has the advantages of being high in birefringence rate, keeping linear polarization, being large in mode filed area and the like.

The invention discloses a method and a device for controlling a mode light power, and relates to the technical field of mode division multiplexing transmission. The device comprises a sending end, a transmission link, a receiving end and a feedback control unit, wherein the sending end, the transmission link and the receiving end are sequentially connected; the feedback control unit is connected with the sending end and the receiving end respectively; the transmission link further comprises a few-mode optical fibre and an optical fibre amplifier. According to the method and the device disclosed by the invention, the receiving power or the light signal-to-noise ratio of the light beam of each mode are acquired through the receiving end, an input power ratio is determined by the feedback control unit according to the receiving power or the light signal-to-noise ratio, the input power of the light beam is adjusted by the sending end according to the input power ratio, thus realizing control on the input power of each mode, and improving the overall transmission performance of the system.

The present invention mainly utilizes the spontaneous raidation noise of backward pump, i.e. light power level of ASE to implement autoamtic control of Raman gain of Raman optical-fibre amplifier andcompensation. Its Raman optical-fibre amplifier is characterized by that at the signal light detection place a combination of filter and photoelectric detector for detecting the backward ASE power ofRaman optical fibre amplifier nearby dirrerent wavelength is added, the output of the photoelectric detector is connected with control unit of automatic regulation of gain of Raman amplifier.

The invention relates to an optical fiber beam combiner and a preparation method thereof, and the technical problem that reverse isolation performance for protection of a pump laser is poor is solved. The optical fiber beam combiner is composed of an input multimode fiber, an input signal optical fiber and an output optical fiber. After fused biconical tapering is carried out on a bare fiber of the input multimode fiber and a bare fiber of the input signal optical fiber to some extent, the bare fiber of the input multimode fiber and the bare fiber of the input signal optical fiber are perpendicularly cut from the middle to be connected with a bare fiber of the output optical fiber in a fused mode. The input signal optical fiber is an optical fiber having a cladding is formed by random optical fibers with claddings in a fused connection mode. The optical fiber beam combiner of the structure has excellent reverse isolation performance, well protects the pump laser, is especially applied to a high-power fiber laser and an optical fiber amplifier, and has the advantages of being simple in manufacturing process, high in coupling efficiency, stable in performance and the like.

The invention is light-path mixer in optical communication field, in which wave-division multiplexer, optical isolator and spectral coupler are integrated, used in fibre-optical amplifier. In light-path direction, it in turn includes the first double fiber-optical ocillator whose output end face is pasted with WDM filtering piece, wedge-shape isolator composed of two double-fraction crystal wedgepieces and one Faraday rotation crystal, hexagon-section spectral prism and the second double fibre-optical collimator; and the wedge-shape isolator and the spectral prism can be clamped between two glass pieces and together placed in permangnet magnetic ring.