18 results about "Fibre amplifier" patented technology

The invention relates to a double-optical-comb laser and a laser spectrum measurement system, and the double-optical-comb laser comprises a pumping source which is used for generating pumping light. The optical fiber amplifier is connected with the output end of the pumping source, and the output end of the optical fiber amplifier is connected with the first optical fiber coupler. The first optical fiber coupler is connected with the first mode-locked laser cavity and the second mode-locked laser cavity. An output light path of the first mode-locked laser cavity is connected with the second optical fiber coupler, an output light path of the second mode-locked laser cavity is connected with the second optical fiber coupler, and the second optical fiber coupler is used for carrying out beam combination and frequency beating on the two paths of laser. The optical path delay line is used for adjusting the laser repetition frequency difference between the first mode-locked laser cavity and the second mode-locked laser cavity. The double-optical-comb laser not only overcomes the defects that an existing double-optical-comb system is complex, expensive and inconvenient to tune, but also has the advantages of being compact in structure, high in stability, high in output pulse energy and tunable in repetition frequency difference.

The invention discloses an ultra-wideband weak signal detection method and system based on all-optical oscillation and phase-amplitude conversion. The method comprises the steps that spontaneous radiation light generated by an erbium-doped optical fiber amplifier is used as an optical carrier; modulating a weak radio frequency signal to be measured received by an antenna to the optical carrier through an optical modulator to form a modulated optical signal; the modulated optical signal is injected into an all-optical oscillation circuit composed of double loops, the all-optical oscillation circuit generates multimode optical oscillation by adjusting an optical attenuator, and the all-optical oscillation circuit comprises a double-loop interference structure; performing phase-amplitude conversion by adjusting the delay difference of the two light paths in the double loops to form an equivalent microwave photon filter so as to select and amplify the modulated light signal corresponding to the radio frequency signal of the set frequency band; and converting the selected and amplified modulated optical signal into an electric signal, and performing spectral analysis to detect the weak radio frequency signal to be detected.

The invention relates to a device (102, 402, 502, 602, 702, 802) for generating a signal (103) for illuminating a fibre Bragg grating (101) in a fibre Bragg grating sensor (10), in particular for detecting traction axes, wherein the device (102, 402, 502, 602, 702, 802) comprises a pump laser (109), a laser medium (110), in particular an erbium-doped fibre amplifier, and a chirped fibre Bragg grating (111), wherein the pump laser (109) is designed to pump the laser medium (110) for emitting light, wherein the chirped fibre Bragg grating (111) is designed to reflect a portion of the light into the laser medium (110), wherein the laser medium (110) is designed to amplify the portion of the light for the signal (103) for illuminating the fibre Bragg grating (101) in the fibre Bragg grating (10). The invention also relates to a method for generating the signal (103).

The utility model provides an in-band pumping optical fiber amplifier. The optical fiber amplifier comprises a first isolator, a first gain optical fiber and a second isolator which are sequentially arranged along the direction of an optical path, at least one first beam combiner is arranged between the first isolator and the second isolator and is connected with at least one pumping device in a beam combining mode, and the pumping device is an amplifier structure pumping device or an oscillator structure pumping device. According to the utility model, the design is reasonable, the 1535nm pumping wavelength selected by the optical fiber amplifier and the target L-band laser wavelength (1565nm-1625nm) are in the same energy band of erbium ions, the quantum loss between the 1535nm pumping wavelength and the target L-band laser wavelength is small, the pumping efficiency of the laser can be effectively improved, and the thermal load of the laser can be reduced, so that the light output power and efficiency of the laser are improved, and the noise characteristic of the laser is improved.

The application discloses a kind of adjustable terahertz wave sources based on soliton mode-locked fiber laser resonant sideband, including sequentially arranged fiber laser, fiber amplifier, aspheric lens, photoconductive antenna and terahertz wave filter along optical path, the lens is bonded at the back of the photoconductive antenna, fiber laser is connected with fiber amplifier, the light output by fiber amplifier enters aspheric lens, the output beam of aspheric lens is irradiated on photoconductive antenna, and outputs electrical signal, and terahertz wave is filtered out after electrical signal passes through terahertz wave filter.The application utilizes the tunability of resonant sideband spacing in soliton mode-locked fiber laser, and obtains adjustable terahertz signal by optical mixing, avoids the complexity of the previous terahertz wave generation system pumped by two lasers, and the instability of output terahertz wave caused by double-wavelength laser as pump source, so that the system structure is more compact, adjustment is convenient, and the conversion efficiency of optical to terahertz wave of terahertz wave generation system is improved.

The invention discloses a temperature control system and method for an L + + EDFA Erbium fiber heat preservation box, and relates to the technical field of automatic control, and the system comprises a temperature sensor, a controller, a PWM drive circuit, and a heating sheet in the Erbium fiber heat preservation box. The core lies in that the controller operates an improved PID control algorithm, and the algorithm integrates an integral anti-saturation mechanism and differential item smoothing processing. The method comprises: sampling the temperature of a heating sheet and calculating an error; calculating items P, I and D; pre-calculating the sum of the three items and limiting the output; the key of output limitation is to carry out integral anti-saturation processing, and when the output is saturated, integral accumulation is suspended to prevent an integral item from being saturated; and finally outputting a PWM signal to control the heating power. According to the invention, the problems of overshoot and continuous oscillation caused by residual heat in a thermal hysteresis system in traditional PI control are effectively solved, and rapid, stable and high-precision temperature control in a wide environment temperature range is realized.

The invention provides a design method and system of an erbium-doped optical fiber amplifier with a high signal-to-noise ratio, and relates to the technical field of optical fiber amplifiers, an electrical system and an optical system are connected through a pump laser, and the erbium-doped optical fiber amplifier with the high signal-to-noise ratio is obtained; temperature error control and current supply are carried out on the pump laser through the electrical system; carrying out two-characteristic fusion processing and optimization adjustment on an optical signal output by the pump laser through an optical system to obtain optimization adjustment information; acquiring temperature error information, supply error information, simulation error information and adjustment error information; according to the invention, the requirement for the size of the pump light is reduced, the requirement for the energy consumption is reduced, the dual-wavelength high signal-to-noise ratio fusion is realized, and the stability of the current is adjusted according to the fluctuation temperature influence coefficient, so that the method and the device have the advantages that the requirements for the size of the pump light and the energy consumption are reduced; and meanwhile, influence analysis of current stability on temperature is realized.

This invention discloses a wide-tunable single-passband microwave photonic filter and its construction method. The filter includes a light source device for generating a supercontinuum light source, comprising a generator, an RF power amplifier, a DFB laser, a first erbium-doped fiber amplifier, a first variable optical attenuator, and a highly nonlinear fiber connected in sequence. An optical filter for selecting a certain width of supercontinuum light source is connected between the light source device and a MZI structure for spectral segmentation of the supercontinuum light source. The MZI structure is connected to a photodetector via a single-mode fiber and a second erbium-doped fiber amplifier. The photodetector is connected to the MZI structure via a vector network analyzer. This application features a simple structure, low cost, and the constructed complex coefficient filter eliminates the fundamental frequency response.

The invention discloses a coherent suppression interference signal generation method based on optical time stretching. The method relates to the technical field of optical communication, the technical field of microwaves and the technical field of electronic countermeasures. The method comprises a mode-locked laser MLL, a dual-drive Mach-Zehnder modulator DDMZM, an arbitrary waveform generator AWG, a vector signal generator VSG, an erbium-doped fiber amplifier EDFA, a dispersion compensation fiber DCF and a photoelectric detector PD. An MLL and a DDMZM are adopted to copy a radar signal and a phase step signal in a frequency domain, controllable delay inequality is applied to the copied signal by utilizing the time stretching capability of a DCF, a coherent suppression interference signal is generated through PD beat frequency, coherent suppression interference can be carried out on a synthetic aperture radar (SAR), an inverse synthetic aperture radar (ISAR), a pulse Doppler radar and a continuous wave radar, and the method has the advantages of being simple in structure, convenient to operate and high in practicability. The requirements for transmitting power and parameter reconnaissance are reduced, the limitation of frequency bands and bandwidths of a traditional electronic interference system is overcome, and the future development trend of an electronic countermeasure system is met.

The application discloses a single-seed-source-based all-fiber flat ultraviolet-mid-infrared supercontinuum laser, which comprises a seed laser, two-stage ytterbium-erbium-doped fiber amplifiers, a high-nonlinear fiber NL-1550, a large-mode-field ytterbium-erbium-doped fiber amplifier, a large-mode-field ytterbium-doped fiber amplifier, a photonic crystal fiber and a passive fluorine-doped fiber which are connected in sequence; wherein the seed laser outputs seed pulse laser of 1.55 mu m, and finally outputs supercontinuum laser with a spectral range of 370-4500 nm, covering ultraviolet-mid-infrared bands. The application adopts an all-fiber structure, has high stability and portability, reduces the loss in the process of light transmission and the system complexity, realizes double-wavelength pumping through a seed source, and realizes super-flat spectral output covering ultraviolet to mid-infrared through a multi-stage amplification structure and a multi-stage nonlinear medium structure.

An ultra-narrow laser spectral width measurement and calibration instrument relates to the fields of laser communication and optoelectronic technology. The ultra-narrow laser spectral width measurement and calibration instrument includes: an ultra-narrow laser source under test (1), a 3dB optical coupler (12), an erbium-doped fiber amplifier (2), a polarization controller (3), a polarization beam splitter (4), first to fourth optical circulators (31), (32), (33), and (34), a first fiber grating reflector (51), a second fiber grating reflector (52), a first polarization-maintaining fiber (61), a second polarization-maintaining fiber (62), a first optical isolator (71), a second optical isolator (72), a 1:9 optical coupler (6), a first adjustable Faraday polarization mirror (81), a second adjustable Faraday polarization mirror (82), a 3×3 optical coupler (7), a spectrum analyzer (9), and a digital signal processor (10).

The invention discloses a miniature integrated Brillouin fiber laser based on a resonant cavity, and belongs to the technical field of fiber lasers. The fiber laser comprises a laser main body which comprises a first laser, an erbium-doped fiber amplifier, a first dense wavelength division multiplexer, a circulator and a resonant cavity; the homodyne phase locking structure comprises a second laser, a bias control panel, an intensity modulator, a signal source, a photoelectric detector, a frequency mixer, a homodyne phase locking plate and a piezoelectric ceramic driver; the probe signal is shot down by the photoelectric detector after surrounding the resonant cavity for a circle, and is subjected to frequency beating with the reference signal to obtain an error signal carrying resonant cavity delay jitter; the homodyne phase-locked plate processes the error signal and outputs a control signal; and the piezoelectric ceramic driver receives the control signal and controls the small integrated piezoelectric ceramic compensation device. Rapid and high-precision compensation of the cavity length jitter of the resonant cavity is realized through the small integrated piezoelectric ceramic compensation device, and the absolute stability of the resonant cavity of the Brillouin fiber laser is finally improved.

The invention discloses an erbium-doped fiber amplifier performance automatic test system, and relates to the technical field of optics, in the system, a light source is respectively connected with a first light input end of a 2 * 2 optical switch and a light input end of a tested EDFA through an optical calibration module and a 50: 50 optical splitter, and a second light input end of the 2 * 2 optical switch is connected with a light output end of the tested EDFA; two light output ends of the 2 * 2 optical switch are respectively connected with a spectrograph and a power meter OPM2; in the system calibration stage and the test stage, the test host performs unified control and scheduling, and the test host calibrates the measurement results of the power meter and the spectrometer by using the system calibration value determined in the system calibration stage, so that multiple performance indexes including the output optical power, the gain flatness and the noise spectral line of the tested EDFA can be obtained. Manual intervention is not needed in the testing process, and EDFA multi-performance testing can be automatically completed with high efficiency, high precision and high consistency.

Provided in the embodiments of the present disclosure are a method for amplifying optical transmission, an optical amplifier, a computer program product, and a storage medium. It is proposed to design a new operating mode in an erbium-doped fiber amplifier; when a line fault is detected, the erbium-doped fiber amplifier can enter said operating mode. In the operating mode, an input optical signal can be blocked on a transmission link within the erbium-doped fiber amplifier, so that an output unit which is not affected by the input optical signal can be isolated within the erbium-doped fiber amplifier; on this basis, during a fault period, the output unit can be controlled to generate an output optical signal on the basis of an expected output power.

The application provides a design method and system of an erbium-doped fiber amplifier with high signal-to-noise ratio, relates to the technical field of fiber amplifiers, and connects an electrical system and an optical system through a pump laser to obtain the erbium-doped fiber amplifier with high signal-to-noise ratio; the electrical system is used for temperature error control and current supply of the pump laser; the optical system is used for two characteristic fusion processing and optimal adjustment of optical signals output by the pump laser to obtain optimal adjustment information; temperature error information, supply error information, simulation error information and adjustment error information are obtained; a fluctuation current influence coefficient and a current temperature influence coefficient are obtained, and then a fluctuation temperature influence coefficient is obtained; current stability is adjusted according to the fluctuation temperature influence coefficient; the application reduces the requirements for the size of pump light and energy consumption, realizes high signal-to-noise ratio fusion of dual wavelengths, and realizes analysis of the influence of current stability on temperature.

The invention provides a terahertz signal frequency mixing device and method based on a microwave photon technology. The device comprises a seed laser, a phase modulator, a signal generator, an optical coupler, a slave laser, an erbium-doped optical fiber amplifier, a photoelectric semiconductor device, a coplanar probe, a terahertz signal generator, a direct current bias device, a direct current voltage source and a signal analyzer. Wherein the phase modulator is used for performing phase modulation on a laser signal output by the seed laser to obtain a main laser frequency comb; the signal generator is used for providing a modulation signal; the subordinate laser is used for performing interference on the optical signal passing through the optical coupler and a laser signal generated by the subordinate laser; the terahertz signal generator is used for feeding a generated terahertz signal into the photoelectric semiconductor device through the coplanar probe to act with a local oscillator signal generated by the photoelectric semiconductor device to realize frequency mixing, an intermediate frequency signal is obtained, and through the device, the integration is improved, and the physical size and complexity of the system are reduced.

The invention discloses an all-fiber LP11 mode laser based on a single-mode erbium-doped fiber amplifier. A single-mode erbium-doped fiber amplifier, a single-mode fiber circulator, a single-mode fiber grating, a first self-focusing lens group, a few-mode fiber, an LP11 mode coupler, a second self-focusing lens group and the like which are cascaded form an oscillation circuit, and high-purity LP11 mode laser is directly generated, wherein the first self-focusing lens group, the few-mode fiber, the LP11 mode coupler, the second self-focusing lens group and the like are connected in a staggered mode. Wherein the single-mode erbium-doped fiber amplifier is a gain part of the laser; the single-mode fiber circulator and the single-mode fiber grating form a filtering part of the laser; the input end of the first self-focusing lens group is connected with the single-mode optical fiber, the output end of the first self-focusing lens group is connected with the few-mode optical fiber, an LP11 mode is excited in the few-mode optical fiber through staggered connection, LP11 mode light is output through one output end of the LP11 mode coupler, and the other output end of the LP11 mode coupler is connected to the second self-focusing lens group through the few-mode optical fiber; the input end of the second self-focusing lens group is connected with the few-mode optical fiber, the output end of the second self-focusing lens group is connected with the single-mode optical fiber, LP11 mode light in the few-mode optical fiber is converted into LP01 mode light of the single-mode optical fiber through dislocation connection, finally, the LP01 mode light returns to the input end of the single-mode erbium-doped optical fiber amplifier, and optical feedback is completed. After the light in the optical loop is subjected to feedback amplification for several times, oscillation of the LP11 mode light is finally formed and output through the LP11 mode coupler.

A low-hardware-complexity optical channel estimation method based on a cascade MZM framework comprises a continuous wave laser, a polarizer, a multi-channel arbitrary waveform generator, a Mach-Zehnder modulator, a voltage source, an erbium-doped optical fiber amplifier, an optical attenuator, a photoelectric detector, an oscilloscope and the like, and high-speed and high-parallelism real-time channel estimation is achieved under low hardware complexity. According to the method, pilot signals and subcarrier signals are respectively loaded by using the cascaded MZMs, mapping of radio frequency signals is directly carried out in the optical field, a large amount of matrix calculation in channel estimation is processed in the optical field, microsecond time delay consumed in complex signal processing steps such as digital-to-analog conversion and serial-to-parallel conversion is avoided, and the accuracy of channel estimation is improved. An ultra-low nanosecond delay and multi-channel parallel channel estimation effect is realized; the Fourier matrix is simplified by using the matrix condition number theory, and the complexity of the number of hardware devices and the light splitting loss is reduced on the premise of ensuring the channel estimation accuracy, so that the signal noise is improved to a certain extent, and the communication quality is improved.