50results about How to "Achieve tunable" patented technology

The invention discloses a multi-dimensional multiplexing soliton optical fiber laser device which comprises a laser pump source and an annular laser resonant cavity consisting of a gain medium, a dispersive medium, a wavelength division multiplexer, an optical coupler, an optical circulator, a polarization controller and a polarizer. The laser pump source and the gain medium work together so as toprovide a gain amplification mechanism for laser device operation. The dispersive medium can be used for chromatic dispersion compensation of pulse laser so as to achieve chromatic dispersion management of an internal optical path of the laser device, and the optical circulator is a non-reciprocal optical transmission device for coupling the chromatic dispersion medium to construct a bidirectional transmission optical path structure. Via use of the polarization controller, a local polarization state of the internal optical path of the laser device can be changed, and mode-locking operation ofthe pulse laser and adjustment and switching of a mode-locking state can be realized. The multi-dimensional multiplexing soliton optical fiber laser device of the invention can be used for bidirectional transmission, and mode-locking laser pulses can be respectively obtained, generation of polymorphic soliton pulses can be supported, and a wideband wavelengths tuning function and a multiple wavelength switching function can be fulfilled via output laser pulses.

A tunable single-polarization Brillouin erbium-doped optical fiber laser device with super narrow linewidth comprises a narrow linewidth pump laser, a three-port circulator, a wavelength division multiplexer, a section of erbium-doped optical fiber wound on a piezoelectric ceramic ring, an erbium-doped optical fiber pump light source and a narrow-band optical filter and an optical fiber coupler with a coupling mode of 2*2 or 1*2. The narrow linewidth pump laser is connected to a first port of the circulator through an optical fiber, a second port of the circulator is connected with a reflecting port of the wavelength division multiplexer through an optical fiber, the erbium-doped optical fiber pump light source is connected with a passband port of the wavelength division multiplexer through an optical fiber, a common port of the wavelength division multiplexer is connected with the erbium-doped optical fiber and then connected to a third port of the optical fiber coupler, a third port of the circulator is connected to a first port of the optical fiber coupler through the narrow linewidth pump laser, and a fourth port of the optical fiber coupler outputs laser. The tunable single-polarization Brillouin erbium-doped optical fiber laser device with the super narrow linewidth achieves output of tunable single-polarization Brillouin erbium-doped optical fiber laser with the super narrow linewidth.

The invention discloses a microwave photon filter of a multi-wavelength light source and a tuning and reconfiguring method of the microwave photon filter. The microwave photon filter of the multi-wavelength light source comprises a multi-wavelength light source generator and a microwave filter device. The microwave filter device comprises a phase modulator, an adjustable dispersion compensator, a first erbium-doped optical fiber amplifier, a photoelectric detector and a vector network analyzer. A comb-shaped optical fiber of the multi-wavelength light source generator is a programmable optical filter. By observing response curve of the network analyzer, dispersion value of the adjustable dispersion compensator is adjusted, time delay between adjacent optical wavelengths of adjacent multi-wavelength light is changed continuously, and central continuous tuning of the microwave photon filter can be realized. The number of comb-shaped pass bands is set by the programmable optical filter to change the number of emitting wavelengths, and adjustment of the bandwidth of the microwave photon filter is realized. Tunable capacity and reconfigurability of the microwave photon filter are realized, and the microwave photon filter can be more flexibly used for the microwave signal processing system.

The invention discloses a tunable single-core Photonic Crystal Fiber (PCF) SPR single polarization wavelength splitter, relates to a tunable fiber wavelength splitter, belongs to the field of fiber communication and optical devices, and is suitable for the fields of wavelength division multiplexing / demultiplexing, fiber sensing and laser systems. The shortcomings of fixed wavelength splitting of a general PCF wavelength splitter, small bandwidth, insufficient mode coupling and failure to realize beam splitting using a single-core PCF are overcome. In a single-core PCF (7), symmetrical upper (2-1) and lower air holes (2-2) are plated with metal materials (8-1, 8-2) on the inner side walls thereof. According to an SPR mixed mode coupling effect and a single polarization filtering property, when the light containing A and B wavelengths enters the PCF (7), the X polarized light of the light of the A wavelength is lost and Y polarized light is output, the light of the B wavelength is the other way around, and thus the light of the two wavelengths is split. In addition, according to a magneto-optic effect, the magnetic fluid refractive index in an oval air hole (3) varies with a magnetic field, and finally, the single polarization wavelength splitting is enabled to be tunable.

The invention discloses a variable-coefficient microwave photonic filter based on a wavelength interval tunable laser. The variable-coefficient microwave photonic filter based on the wavelength interval tunable laser is mainly composed of the wavelength interval tunable multi-wavelength laser and a Mach-Zehnder interferometer. According to the multi-wavelength laser, a Sagnac ring composed of pohotonic crystal fiber has a frequency selected filter effect, through changing the surrounding temperature of the pohotonic crystal fiber filled with glycerol and tuning the frequency selection characteristics of the Sagnac ring, the multi-wavelength laser outputs laser with different wavelength intervals so as to change the free spectrum range of the filter. Through regulating a variable optical delay line in the Mach-Zehnder interferometer and changing the arm length difference of the Mach-Zehnder interferometer, the transmission characteristics are changed, and carrier signals obtain different tap coefficients to obtain the variable-coefficient microwave photonic filter. The tunable and reconfigurable characteristics of the microwave photonic filter can be simultaneously realized through easily regulating the surrounding temperature of the pohotonic crystal fiber and the variable optical delay line.

The invention provides a tunable narrow-linewidth array single-frequency fiber laser. The fiber laser comprises a semiconductor laser chip array portion, a tunable narrow-linewidth array single-frequency fiber laser array portion and a miniature short fiber power amplification portion. The tunable narrow-linewidth array single-frequency fiber laser can simultaneously achieve output of array single-frequency fiber lasers with 100GHz laser wavelength channel spacing, the single-transverse mode power is larger than or equal to 100mW, the signal to noise ratio is larger than or equal to 65dB, and the narrow-linewidth is smaller than or equal to 10kHz. A tunable function of central wavelength (or output ways) of each narrow-linewidth array single-frequency fiber laser output unit can be effectively achieved based on modes such as precise temperature control technology and selectivity pumping source working control, and accordingly real-time and effective tunable performance of output wavelength covering scopes formed by single-frequency fiber lasers in a narrow-linewidth array mode can be achieved. The tunable narrow-linewidth array single-frequency fiber laser can be widely used for coherent light communication and the application field that high-precision sensing and detection are carried out on a plurality of goals.

The invention discloses a device for generating laser with new wavelength from ultrashort laser pulse with different sum frequencies, comprising at least one picoseconds laser, at least one femto-second laser, at least one nonlinear crystal, a synchronous control system and a light path adjusting system, wherein the picoseconds laser is used for generating picoseconds laser; the femto-second laser is used for generating femto-second laser; the synchronous control system is used for realizing the active synchronization of each laser; the nonlinear crystal is used for generating nonlinear frequency conversion between synchronous lasers; and the light path adjusting system is used for adjusting the length of an oscillating cavity of the femto-second laser and adjusting the beam transmission of the femto-second laser and the picoseconds laser. The invention combines different ultrashort pulse lasers and utilizes an electronic phase-locked loop feedback circuit to control the telescoping degree of a piezoelectric actuator and the displacement of an electric platform so as to realize active synchronization with high precision, and on the basis, sum frequency is performed to the synchronous laser pulse in a nonlinear crystal with a matched phase, thereby generating a broadband ultrashort pulse laser with a new wavelength.

The invention discloses a mobile terminal antenna device, and relates to the technical field of communication antennas. The mobile terminal antenna device comprises a first radiator; the first radiator is connected with the first signal output end of a processor through a signal source; one end of a second radiator is connected with the first radiator through a switch circuit, and the other end ofthe second radiator is grounded through a first active switch; and the second signal output end and the third signal output end of the processor are connected with the control signal input ends of the switch circuit and the first active switch respectively. Through the tuning design of a multi-antenna body by the switch circuit, the design that the parasitic frequency band is tunable, the antennaradiators are reconfigurable and multiple antennas are compatible in a low-radiation environment is realized, and multiple tunable schemes can be provided in a parasitic antenna and reconfigurable radiator mode, so that the broadband / multi-frequency design of the antennas and the near-distance high-isolation design of the multiple antennas are realized.

The invention provides a narrow-linewidth tunable laser system and an operation method thereof. A tunable laser module of the system comprises a semiconductor laser, a driving circuit and a wavelength-tunable control submodule, wherein the driving circuit and the wavelength-tunable control submodule are connected with the semiconductor laser. A switch voltage stabilizer, connected with an inductor and a diode, of a power management submodule enables positive voltage to be converted into negative voltage so as to supply electricity to the system. A microcontroller connected with a host is connected with the driving circuit through digital-to-analog conversion to transmit instructions of the host and states of the laser. The microcontroller and a power failure detection submodule are used for detecting circuit voltage of the laser at regular time, and power is recovered in time when power failure is found out. The operation method of the narrow-linewidth tunable laser system includes the steps that after being initialized, the microcontroller transmits preset default data frames to the laser, the data frames returned by the laser are read, the situation that the data frames have no error is determined, whether power failure occurs or not is detected at regular time, updated instructions of the host are received and transmitted to the laser, and the current working state information of the laser is transmitted to the host. The system only needs to be powered up by a single power supply and can be used easily in an embedded mode. A tuning control interface of the host is simple and visual, and reliable operation is guaranteed through power failure self-detection.

The invention discloses a 2-micron wave band tunable thulium-holmium codoped mode-locking all-fiber laser, and belongs to the field of laser techniques and non-linear optics. The 2-micron wave band tunable thulium-holmium codoped mode-locking all-fiber laser mainly comprises a laser pumping source, a wavelength division multiplexer, thulium-holmium codoped optical fiber, a circulator, an isolator, a saturable absorber, a saturable absorber mirror, a coupler, a polarization controller, a filter, passive optical fiber, and the like. As the thulium-holmium codoped optical fiber is taken as a gain medium and the saturable absorber and the saturable absorber mirror as passive mode-locking devices, and furthermore by changing the penetration wavelength of the tunable filter, output of 2-micro wave band, tunable wavelength and short pulse is achieved. Due to adoption of the whole structure of the 2-micron wave band tunable thulium-holmium codoped mode-locking all-fiber laser, all-fiber welding is achieved, and the 2-micron wave band tunable thulium-holmium codoped mode-locking all-fiber laser has the advantages of simple structure, good environment stability, high efficiency and the like, and is easy in industrial application.

The invention discloses a mid-infrared narrow-band tunable filter. The mid-infrared narrow-band tunable filter comprises a substrate and is characterized in that a first dielectric plating layer is arranged on the substrate, graphene is arranged on the first dielectric plating layer, a second dielectric plating layer is arranged on the graphene, a third dielectric plating layer is arranged on thesecond dielectric plating layer, and the third dielectric plating layer is etched into a grating layer. The novel mid-infrared narrow-band tunable filter has the advantages that graphene Fermi energychange is achieved by using the features of the graphene and changing static bias voltage, and accordingly transverse electric (TE) polarized light tunable narrow-band reflection is achieved, and therequirement of reflection peak position dynamic change is satisfied.

The invention provides a continuously-tunable single-frequency optical fiber laser. The continuously-tunable single-frequency optical fiber laser includes a multi-component glass optical fiber, a broadband optical fiber grating, a narrowband optical fiber grating, a wavelength division multiplexer, a pumping source, an optical isolator and a laser frequency tunable device, wherein the laser frequency tunable device is composed of a first thermoelectric cooler (TEC) and a second thermoelectric cooler (TEC) which are fixed at different positions in a single-frequency laser resonant cavity. According to the continuously-tunable single-frequency optical fiber laser of the invention, a multi-component glass optical fiber-based short linear resonant cavity and an all-optical fiber optical path structure are utilized, such that the laser can perform single-frequency operation stably and reliably; two thermoelectric coolers (TEC), namely double-temperature control tuning technology, are utilized to adjust and change the temperature distribution inside the cavity widely and regionally, and a temperature effect will cause constant changes of the length of the resonant cavity and the reflection spectrum of the narrowband optical fiber grating respectively, and therefore, the frequency of the laser can be tuned continuously and widely in real time. Thus, the continuously-tunable single-frequency optical fiber laser is advantageous in simple structure, low cost and high repeatability.

The invention belongs to the technical field of fiber lasers, and particularly relates to an incoherent super-continuum spectrum light source with controllable spectrum and tunable output power. The incoherent super-continuum spectrum light source comprises a random pulse fiber laser, a single-mode fiber, a double-clad ytterbium-doped / tapered ytterbium-doped fiber amplifier and a highly-nonlinearintermediate infrared soft glass fiber. The incoherent super-continuum spectrum light source can realize three modes of incoherent super-continuum spectrum output such as a near-infrared band or an intermediate infrared band, a visible light-near infrared band or a near infrared-intermediate infrared band and a visible light-intermediate infrared band through selecting different super-continuum generation modules. In addition, through performing combined control on the length of the single-mode fiber, the output power of a pumping source in the double-clad ytterbium-doped / tapered ytterbium-doped fiber amplifier and the length of the highly-nonlinear intermediate infrared soft glass fiber, the incoherent super-continuum spectrum light source not only can realize control on the output spectrum range and shape, but also can realize tunable output power of the super-continuum spectrum under the condition that the output spectrum range and shape are fixed.

The invention discloses a tunable all-fiber mode-locked laser. A fiber laser structure with high repetition rate, high power, simple structure and high efficiency is generated by utilizing rare-earth doped fiber as a laser gain medium, working in a total positive dispersion region, splitting light by a polarising beam splitter, utilizing a band pass tunable long period fiber grating filter as mode-locked laser center wavelength selection and the spectrum filter light impulse compression of the mode-locked laser, and semiconductor saturable absorber as a mode-locked element and the like. The tunable all-fiber mode-locked laser is a mode-locked ultra short laser pulse laser capable of realizing all fiber with environmental stability and novel structure, can output picosecond and femtosecond light impulse polarization laser with laser wavelength more than 1mu m, and can be widely applied in the fields of biology, medication, optical precision finishing and the like.

The invention provides an optical filter, comprising N+1 stages of optical switches, wherein each stage of optical switch comprising a first input end, a second input end, a first output end and a second output end; N stages of second-order micro-ring optical filter units, wherein each stage of second-order micro-ring optical filter unit comprises two micro-ring resonant cavities, the radiuses of the micro-ring resonant cavities of the N stages of second-order micro-ring optical filter units are different, and the kth-stage second-order micro-ring optical filter unit is connected with the first output end of the kth-stage optical switch; an input optical waveguide unit which is used for inputting a received optical signal into the first-stage optical switch; an N-stage first waveguide, wherein a kth-stage first waveguide is connected with the output end of the kth-stage second-order micro-ring optical filter unit and the first input end of a (k+1)th-stage optical switch; an N-stage second waveguide, wherein a kth-stage second waveguide is connected with the second output end of the kth-stage optical switch and the second input end of the (k+1) th-stage optical switch; and an output optical waveguide unit which is connected with the (N+1)th-stage optical switch and is used for outputting the filtered optical signal.

The invention belongs to the field of optoelectronic device manufacture, in particular to an optical channel performance monitoring module (OPM) which comprises basal units such as a collimator, an electrooptical ceramic wafer, an electrooptical probe, a voltage driver, and the like. Both sides of the electrooptical ceramic wafer are respectively plated by reflecting films to form an F-P filter, and the tunability of the F-P filter is realized by changing the refractive index of electrooptical ceramic. The refractive index of the electrooptical ceramic can be changed through changing an electric field on the electrooptical ceramic so that the transmissive wavelength of the F-P filter moves to scan the wavelengths and the power of various optical channels in the whole communication bandwidth and obtain the optical signal-to-noise ratios (OSNR) of the channels by certain algorithms and treatments. Due to the adoption of the rapidly responded electrooptical ceramic, the scanning time of the OPM reaches a sub-millisecond level, the defects of the prior OPMs of diffraction type and interference type are overcome, and the invention has the advantages of high response speed and stability, small size, simple structure, no diffraction influence and no mechanical control.

A tunable multi-wavelength multiplexing spectrum modulation and separation system for high-power fiber laser amplification comprises a narrow linewidth seed source, a wavelength division multiplexing module, a spectrum modulation module, a first pre-amplifier, a wavelength separation module, a second pre-amplifier, a main amplifier and an end cap. The spectrum modulation module injects an electrical signal and adopts a tunable filter and a variable attenuator, so that the tunable spectrum line width can be realized, and the system has important application value in many different fields. According to the multi-wavelength common spectrum modulation broadening and separation system, multi-wavelength beam combination and high-precision and high-signal-to-noise-ratio separation can be achieved within the wave band range of 1.0 micrometer or 2.0 micrometers, meanwhile, the same inhibition effect on stimulated Brillouin scattering in multi-wavelength laser high-power optical fiber amplification is achieved, the consistency is shown in laser output power improvement, and the system has the advantages of being high in integration degree, simple in structure, convenient to control and particularly low in manufacturing cost, and miniaturization integration, array expansion and application of large-scale laser array synthesis are greatly facilitated.

The invention relates to a terahertz spectrum measuring system and a method for analyzing a terahertz spectrum of a substance. The terahertz spectrum measuring system comprises two terahertz quantum cascade lasers whose emission ports are arranged in an opposite manner and a vacuum cover arranged between the emission ports of the two terahertz quantum cascade lasers. According to the terahertz spectrum measuring system and the method for analyzing the terahertz spectrum of the substance, advantages of an on-chip dual-frequency comb system can be reserved, a terahertz dual-frequency comb is separated, and the defect that the on-chip dual-frequency comb fails to directly measure the terahertz spectrum of the substance is overcome.

The invention discloses a micro-ring coupling modulation structure based on graphene fine tuning coupling efficiency and an application method thereof; the micro-ring coupling modulation structure comprises a micro-ring waveguide structure, a signal modulation structure, a phase modulation structure and a modulation coupling structure; the micro-ring waveguide structure is a runway type structureand comprises two arc waveguides and two straight waveguides; a signal modulation structure and a phase modulation structure are integrated in the upper straight waveguide area, a certain distance isfixed between the lower straight waveguide area and the modulation coupling structure, and graphene layers are embedded in the signal modulation structure, the phase modulation structure and the modulation coupling structure respectively. According to the micro-ring modulator based on the structure, the coupling efficiency between the micro-ring and the straight waveguide can be finely adjusted, so that the coupling efficiency can reach a desired specific value, the precision is relatively high, the micro-ring modulator plays a role in an application scene in which the coupling efficiency needs to be accurately controlled, and the working wavelength of the structure is tunable; the structure has important application value for a linearized integrated photonic device.

The invention provides a method for realizing the tunable luminescence of a Ce<3+>, Tb<3+> and Eu<3+> doped dichroite structure Mg2Al4Si5O18 fluorescence material through an ion bridge, and belongs tothe technical field of luminescence materials. A chemical general formula of the fluorescence material is (Mg1-x-y-zCexTbyEuz)2Al4Si5O18, wherein the x, the y and the z are mol percentage; the x is greater than 0 and smaller than or equal to 0.1; the y is greater than 0 and smaller than or equal to 0.4; the z is greater than 0 and smaller than or equal to 0.1; photoluminescence spectra of Ce<3+>,Tb<3+> and Eu<3+> in Mg2Al4Si5O18 are respectively positioned in blue light, green light and red light regions; through the Ce to Tb to Eu energy transmission, the tunable luminescence at three chromatic light intensities of blue, green and red can be realized.

The invention provides a tunable random fiber laser based on two gratings. The tunable random fiber laser comprises a laser source, a 1*2 optical fiber coupler, a first random optical pulse generator, a first electro-optical modulator, a first optical isolator, a first erbium-doped optical fiber amplifier, a single side band modulator, a microwave source, a first polarization controller, a second optical isolator, a second random optical pulse generator, a second electro-optical modulator, a third optical isolator, a delay optical fiber, a second erbium-doped fiber amplifier, a second polarization controller, a polarization beam combiner, a fourth optical isolator, an erbium-doped fiber, a polarization maintaining fiber, a random Brillouin dynamic grating, a pumping laser source, a wavelength division multiplexer, a high-reflection fiber bragg grating and a tuning device. According to the invention, the problem that random laser lasing can only be realized by means of a long-distance grating in the prior art is solved, and the laser capable of outputting tunable random laser without a high-power pumping source is provided.

The invention discloses a repetition frequency adjustable dual-wavelength nano-joule picosecond laser, which comprises a single output mode-locked resonant cavity, a 45-degree reflection light guide mirror, an optical isolator, a reflective electro-optic pulse selector, a frequency doubling crystal, a wavelength beam splitter and a 45-degree reflecting mirror. A quarter-wave plate and a polarizingplate are used for forming a single output mode-locked resonant cavity output mirror with adjustable output rate to output a mode-locked picosecond pulse with high repetition frequency and nano-joulepulse energy; the selection of the mode-locked picosecond pulse is realized via the reflective pulse selector to obtain a picosecond pulse with adjustable repetition frequency; frequency conversion is carried out by the frequency doubling crystal to obtain a dual-wavelength nano-joule picosecond pulse laser. The repetition frequency adjustable dual-wavelength nano-joule picosecond laser in the invention adopts the quarter-wave plate and the polarizing plate as the output rate tunable output mirror in the single output mode-locked resonant cavity, to obtain a mode-locked single output with adjustable nano-joule energy, and adopts the reflective electro-optic pulse selector and an emission angle tunable mirror to reduce the high voltage of the electro-optic crystal and meet the requirementsof the laser divergence angle as needed.

The invention provides a tunable thermo-optical filter, and an adjusting method and a manufacturing method thereof, and the tunable thermo-optical filter comprises a substrate, and a first reflector,a metasurface structure and a second reflector which are sequentially arranged in a manner of deviating from the substrate. The metasurface structure comprises a plurality of microstructures which areperiodically arranged. A heating structure surrounding the plurality of microstructures, and a thermo-optic effect structure covering the plurality of microstructures and the heating structure. The heating structure is used for heating the thermo-optic effect structure. When the thermo-optic effect structure is at a first temperature value, the central wavelength of the tunable thermo-optic filter is a first numerical value, and when the thermo-optic effect structure is at a second temperature value different from the first temperature value, the central wavelength of the tunable thermo-opticfilter is a second numerical value different from the first numerical value. The filter is used for realizing high-performance tunable filtering.

This invention refers to a kind of adjustable fiber grating module, which can be used in optical fiber communication. The existing technology has very large limitation, with bad adjusting ability and bad period adjusting ability. Also the period uniformity is hard to realize. Then intention of the invention is to realize the period continuous, adjustable and homogeneous on the base of all the merits of the existing module (mainly about the character of the transferring spectral line). It is also intended to adjust flexibly the character of long period fiber and raster transferring spectral line. The new double-layer graphite rods can adjust the fiber grating module. It includes the smooth board, on which are arranged parallel double-layer graphite rods, the base on the bottom and the action layer on the top. This module has homogeneous period which can change its own number and is continuous. This invention costs little and has large source of material, so it is easy to realize industrial production and reconstruct. Besides, the quality comparing to the price is satisfying, and it has potential big value in the fields of gaining and smoothening of the erbium-doped optical fiber amplifier and the wave filter making.

The invention discloses a multi-dimensional multiplexing soliton optical fiber laser device which comprises a laser pump source and an annular laser resonant cavity consisting of a gain medium, a dispersive medium, a wavelength division multiplexer, an optical coupler, an optical circulator, a polarization controller and a polarizer. The laser pump source and the gain medium work together so as toprovide a gain amplification mechanism for laser device operation. The dispersive medium can be used for chromatic dispersion compensation of pulse laser so as to achieve chromatic dispersion management of an internal optical path of the laser device, and the optical circulator is a non-reciprocal optical transmission device for coupling the chromatic dispersion medium to construct a bidirectional transmission optical path structure. Via use of the polarization controller, a local polarization state of the internal optical path of the laser device can be changed, and mode-locking operation ofthe pulse laser and adjustment and switching of a mode-locking state can be realized. The multi-dimensional multiplexing soliton optical fiber laser device of the invention can be used for bidirectional transmission, and mode-locking laser pulses can be respectively obtained, generation of polymorphic soliton pulses can be supported, and a wideband wavelengths tuning function and a multiple wavelength switching function can be fulfilled via output laser pulses.

The invention discloses a 2-micron wave band tunable thulium-holmium codoped mode-locking all-fiber laser, and belongs to the field of laser techniques and non-linear optics. The 2-micron wave band tunable thulium-holmium codoped mode-locking all-fiber laser mainly comprises a laser pumping source, a wavelength division multiplexer, thulium-holmium codoped optical fiber, a circulator, an isolator, a saturable absorber, a saturable absorber mirror, a coupler, a polarization controller, a filter, passive optical fiber, and the like. As the thulium-holmium codoped optical fiber is taken as a gain medium and the saturable absorber and the saturable absorber mirror as passive mode-locking devices, and furthermore by changing the penetration wavelength of the tunable filter, output of 2-micro wave band, tunable wavelength and short pulse is achieved. Due to adoption of the whole structure of the 2-micron wave band tunable thulium-holmium codoped mode-locking all-fiber laser, all-fiber welding is achieved, and the 2-micron wave band tunable thulium-holmium codoped mode-locking all-fiber laser has the advantages of simple structure, good environment stability, high efficiency and the like, and is easy in industrial application.

The invention discloses an active inductor capable of working at a Ku waveband. The inductor includes a first Q-enhanced transconductor unit (1), a second Q-enhanced transconductor unit (2), a first adjustable input unit (3) and a second adjustable input unit (4). The first Q-enhanced transconductor unit (1) is connected in series with the first adjustable input unit (3) to form a first-stage impedance conversion circuit. The second Q-enhanced transconductor unit (2) is connected in series with the second adjustable input unit (4) to form a second-stage impedance conversion circuit. The first-stage impedance conversion circuit is cascaded with the second-stage impedance conversion circuit. Total equivalent capacitance of the active inductor is enabled to be reduced, impedance conversion frequency is increased, and finally, the active inductor which has a high Q value and a large inductance value and is capable of working at the Ku waveband is obtained.

The invention provides a narrow-linewidth tunable laser system and an operation method thereof. A tunable laser module of the system comprises a semiconductor laser, a driving circuit and a wavelength-tunable control submodule, wherein the driving circuit and the wavelength-tunable control submodule are connected with the semiconductor laser. A switch voltage stabilizer, connected with an inductor and a diode, of a power management submodule enables positive voltage to be converted into negative voltage so as to supply electricity to the system. A microcontroller connected with a host is connected with the driving circuit through digital-to-analog conversion to transmit instructions of the host and states of the laser. The microcontroller and a power failure detection submodule are used for detecting circuit voltage of the laser at regular time, and power is recovered in time when power failure is found out. The operation method of the narrow-linewidth tunable laser system includes the steps that after being initialized, the microcontroller transmits preset default data frames to the laser, the data frames returned by the laser are read, the situation that the data frames have no error is determined, whether power failure occurs or not is detected at regular time, updated instructions of the host are received and transmitted to the laser, and the current working state information of the laser is transmitted to the host. The system only needs to be powered up by a single power supply and can be used easily in an embedded mode. A tuning control interface of the host is simple and visual, and reliable operation is guaranteed through power failure self-detection.