51results about How to "Large wavelength tuning range" patented technology

The invention provides an adjustable laser, comprising a stop band filter module with a plurality of stop bands which are spaced; a gain medium connected to the stop band filter module, wherein emitted light of the gain medium has a plurality of longitudinal modules one of which is overlapped with the stop band of the stop band filter module; a wavelength adjusting module used for adjusting the longitudinal module position of the emitted light of the gain medium during wavelength adjustment of the adjuatable laser, such that the longitudinal modules shift to align with another stop band corresponding to a target wavelength in the stop band filter module. The invention also provides an optical module and a passive optical network system.

The invention discloses a tunable ytterbium-doping double-clad fiber mode-locked laser which belongs to the technical field of lasers. The tunable ytterbium-doping double-clad fiber mode-locked laser is in an annular cavity structure, takes a large-core diameter double-clad ytterbium-doping fiber as a gain medium and works on a total positive dispersion area. The tunable ytterbium-doping double-clad fiber mode-locked laser realizes the mode locking self-starting and stably carries out mode locking by dint of a nonlinear polarization rotation technology and a spectrum filter, is adjustable in filtering bandwidth because the spectrum filter comprises a grating and a slit with adjustable width, has a tuning function and can continuously tune the center wavelength of an output pulse within a gain bandwidth range. The tunable ytterbium-doping double-clad fiber mode-locked laser disclosed by the invention realizes the total positive dispersion mode locking of the large-core diameter double-clad fiber by adopting nonlinear polarization rotation and a spectrum filter technology, obtains the ultrashort-pulse laser output supporting high power and high single-pulse energy, is continuously tunable in center wavelength and is convenient to operate and large in tuning range by composing the spectrum filter by adopting the grating and the slit.

A super Gaussian pulse generation method on the basis of gain reshaping includes the following steps: firstly, a wideband linear chirp laser pulse is generated, and the central wavelength of the wideband linear chirp laser pulse is adjusted to be longer than the intrinsic emission line peak wavelength of the doped gain ion of an optical fiber amplifier; secondly, the gain-narrowed lower triangular chirp laser pulse is obtained after the linear chirp laser pulse is gain amplified by a pre-amplifier selected with the gain coefficient spectral lines all presenting triangular shapes; finally, the super Gaussian pulse is formed by injecting the lower triangular chirp pulse into a main amplifier selected with the gain optical fiber length being 1 to 3 times of that of the pre-amplifier and the central wavelength of the gain spectrum lines being longer than the pre-amplifier. The device capable of realizing the method comprises an optical fiber femtosecond laser oscillator (9-1), a dispersion compensator (9-2), an optical fiber self-similarity pulse amplifier (9-3), a positive dispersion optical fiber pulse stretcher (9-4), a frequency spectrum filter (10), and a front optical fiber amplifier (11) with at least one stage and a main optical fiber amplifier (12).

The invention discloses a distributed Bragg feedback tunable laser and a manufacturing method thereof. The method comprises the following steps: a lower waveguide layer, a multiple quantum well active area and an upper waveguide layer sequentially grow on a substrate; materials of a distributed Bragg feedback area and a phase area are obtained, wherein the band gap wavelengths of the materials of the distributed Bragg feedback area and the phase area are less than the light emitting wavelength of the laser; a grating is manufactured in the feedback area; the cladding and electrical contact layer materials grow on the whole surface of a tube core; an inverted frustum-shaped shallow ridge waveguide structure is manufactured on the cladding and the electrical contact layer of the feedback area, the phase area and a gain area, wherein the waveguide side wall of the structure is a (111) A crystal plane; electrical isolation grooves are etched in the electrical contact layer and ion implantation is carried out on the isolation grooves at the same time to realize electrical isolation between the gain area and the phase area and between the phase area and the feedback area. Through the adoption of the distributed Bragg feedback tunable laser and the manufacturing method thereof, the purpose that the feedback area has low series resistance when the concentration of implanted charge carriers is improved is achieved, and the device wavelength tuning range can be increased and the wavelength tuning sensitivity is improved.

The invention discloses a detection system of photoacoustic spectrometry gas in a fiber laser device cavity, and belongs to the technical field of optical fiber gas detection. The detection system comprises a pump light source, a wavelength division multiplexer and a computer. The annular fiber laser device cavity is jointly composed of the wavelength division multiplexer, rare earth doped fibers, an opto-isolator, a gas chamber, a tunable filter and an optical fiber coupler, wherein an input coupling mirror and an output coupling mirror are placed in the gas chamber; a quartz tuning fork is placed in the proper position in the gas chamber and is used for probing acoustic wave signals generated by laser excitation gas in the fiber laser device cavity; the signals probed by the quartz tuning fork are further exacted by a lock-in amplifier, are acquired by a data collection card and are transmitted to the computer, and after gas concentration inversion is conducted on the signals, gas concentration information is acquired. Combined with the optical fiber laser technology and the photoacoustic spectrometry gas detection technology, the detection system of the photoacoustic spectrometry gas in the fiber laser device cavity has the advantages of being high in sensitivity and cost performance, very low in cost and the like.

The invention relates to a fiber optical laser of an L waveband with tunable wavelength, which is characterized by wide tuning range, simple structure, narrow width of output laser ray and high stability and etc. The fiber optical laser of an L waveband with tunable wavelength comprises a light source and an annular laser chamber, wherein the light source is used for transmitting the light into the annular chamber; the light is partially output by a coupler, and the another part of the light is sent to an optical fiber grating filter with mechanical sensing growth cycle which is in transition connection with the interior of the annular chamber, wherein the optical fiber grating filter with mechanical sensing growth cycle comprises a pressure groove template of which the cycle is P; the pressure groove template is matched with a pair of smooth base plates; an optical fiber of an optical fiber grating with a growth cycle to be written and a balance optical fiber are arranged between the two smooth base plates; and the wavelength regulation of the optical fiber grating filter with mechanical sensing growth cycle is realized by changing the cycle of the pressure groove template with the cycle P under the under that the preset pressure is maintained. The fiber optical laser of an L waveband with tunable wavelength provided by the invention has the advantages that the inhibition band within the annular chamber can be regulated, the gain peak of the annular chamber is changed, and the laser with wavelength tunable is realized.

An optical transmitter includes a reflective semiconductor optical amplifier (RSOA) coupled to an input end of a first optical waveguide. An end of the first optical waveguide provides a transmitter output for the optical transmitter. Moreover, a section of the first optical waveguide between the input end and the output end is optically coupled to a ring modulator that modulates an optical signal based on an electrical input signal. A passive ring filter (or a 1×N silicon-photonic switch and a bank of band reflectors) is connected to provide a mirror that reflects light received from the second optical waveguide back toward the RSOA to form a lasing cavity. Moreover, the ring modulator and the passive ring filter have different sizes, which causes a Vernier effect that provides a large wavelength tuning range for the lasing cavity in response to tuning the ring modulator and the passive ring filter.

The invention discloses a multi-mode interference effect-based widely-tunable single-frequency fiber laser. The laser comprises a high-reflectivity chirped fiber grating, a high-gain fiber, a low-reflectivity chirped fiber grating, a pumping source, an optical isolator, an optical circulator, a fiber etalon and an SMS fiber structure device, wherein the high-reflectivity chirped fiber grating, thehigh-gain and the low-reflectivity chirped fiber grating are sequentially connected to form a short-line resonant cavity part, the optical circulator, the fiber etalon and the SMS fiber structure device form an annular cavity, a stress loading device is fixedly arranged on an upper surface of the SMS fiber structure device, the transmitting wavelength is changed and the tunable filtering is achieved by loading stress onto the SMS fiber structure device, and single-frequency fiber laser output with stable power and wide tuning range is finally achieved. The laser combines the advantages of a composite cavity structure, has the advantages of all-fiber structure, wide wavelength tuning range and the like and can be widely applied to the fields of optical communication, sensing and spectrum.

The invention discloses a V-shaped coupled cavity tunable semiconductor laser unit capable of directly conducting modulation at a high speed. The V-shaped coupled cavity tunable semiconductor laser unit comprises a semi-wave coupler, a wave length reference FP resonant cavity and a wave length tuning FP resonant cavity, wherein short cavity active waveguide and short cavity passive waveguide are connected in series to form the wave length reference FP resonant cavity, long cavity active waveguide and long cavity passive waveguide are connected in series to form the wave length tuning FP resonant cavity, the ratio of the optical length of the short cavity active waveguide to the optical length of the short cavity passive waveguide is equal to the ratio of the optical length of the long cavity active waveguide to the optical length of the long cavity passive waveguide, and therefore the mode jump does not occur when the laser unit directly conducts modulation at the high speed. The laser unit can further comprise a section of thin film resistor added to the top of the semi-wave coupler so that the tuning range can be enlarged, and comprise two sections of active waveguide added outside cavities and deep etching grooves so that the threshold of the laser unit can be reduced, and an optical power meter integrated on a piece is provided. According to the V-shaped coupled cavity tunable semiconductor laser unit, the C wave section and sections in a wider range can be tuned, and performance of conducting direct modulation on each communication wave with the wave length more than 10Gbps is achieved.

A high pulse repetition frequency mode-locking optical fiber laser comprises a pump laser and a laser resonator, wherein the laser resonator is of an FP (Fabry-Perot) cavity structure. A gain medium and a mode-locking component are positioned between end faces of two optical fiber connectors, a bicolor film is plated on the end face of each optical fiber connector, a gain optical fiber is a phosphate optical fiber doped with rare earth ions, the mode-locking component is grapheme, one end of the laser resonator directly outputs via a laser isolator, the other end of the laser resonator is connected with an output end of a wavelength division multiplexer, an input end of the wavelength division multiplexer is connected with the pump laser, the other output end of the wavelength division multiplexer is connected with the laser isolator to output laser light, and the temperature of the laser resonator is controlled by a temperature control system. The high pulse repetition frequency mode-locking optical fiber laser can generate stable picosecond and even femtosecond without external additional modulation, the repetition frequency is larger than 1GHz ultra-short pulse sequence, and the optical fiber laser is simple in structure and capable of realizing all-fiber integration.

The invention provides a single-mode tunable terahertz quantum cascade laser device structure and a manufacturing method. The single-mode tunable terahertz quantum cascade laser device structure at least comprises a semi-insulating GaAs substrate, a GaAs buffer layer, a first contact layer, an active area, a second contact layer, a first metal layer and a second metal layer. The active layer, the second contact layer and the first metal layer form a ridge structure on the first contact layer. The side face of the ridge structure is inclined relative to the end face. The ridge structure is cut into a first sub-ridge structure and a second sub-ridge structure through an interstitial structure in the length direction. By the adoption of the oblique waveguide structure, the transverse mode selection capacity can be improved; on the premise that device single transverse mode output is ensured, the device width is larger, the outgoing beam far-field divergence angle is decreased, the refractive index is changed by injecting current of different magnitudes into two waveguides of a coupled cavity structure THz QCL, the Vernier effect is utilized for achieving the tunable wavelength, and the wavelength tunable range of the single-mode tunable terahertz quantum cascade laser device structure is larger than that of an existing device structure changing the refractive index only through current injection.

The invention discloses a tunable narrow linewidth external cavity semiconductor laser, comprising: a semiconductor gain chip as a laser source; An optical waveguide located on the same optical axis as the gain chip; A grating structure positioned behind the optical waveguide and positioned on the same optical axis as the gain chip and the optical waveguide; A thermistor located on one side of thegain chip and the optical waveguide centerline, avoiding the optical path, the thermistor being located close to the gain chip; An electrode attached to the optical waveguide; A heat sink, a gain chip, a thermistor, an optical waveguide and a grating structure are placed on the same heat sink; A heat sink is placed on the same semiconductor cooling sheet. The invention solves the problems of wavelength jitter and linewidth instability caused by external environment and injection current fluctuation of external cavity laser, thereby realizing accurate control of wavelength and linewidth, and realizing rapid adjustment of wavelength.

The invention discloses a multi-wavelength tunable laser based on a polarization-maintaining chirped phase-shift fiber grating, and belongs to the field of optical communication and instruments. A pumping light source (101) firstly passes through a wavelength division multiplexer (102) and enters the annular cavity structure of a laser; through gain of a doped fiber (103) with a length of 2 meters, the pumping light source passes through a polarization controller (104) and then passes through a polarization-maintaining chirped phase-shift fiber grating filter based on a piezoelectric ceramic; the polarization-maintaining chirped phase-shift fiber grating filter is composed of a polarization-maintaining chirped fiber grating (105), the piezoelectric ceramic (106) and an electric signal generator (107); signals in a bandwidth range are reflected back to a laser resonant cavity through a circulator (108) and a polarization-maintaining even fiber grating (109); and finally multi-wavelength lasers are output from a coupler (110). The multi-wavelength laser mainly is realized through that the signals generated by the polarization-maintaining even fiber grating (109) act on the polarization-maintaining chirped fiber grating (105) so as to import phase shifts. Through changing the locations and number of the imported pi phase shifts, the laser wavelengths and the number of the laser wavelengths can be tuned by the multi-wavelength laser.

The invention, which belongs to the technical field of fiber gratings, in particular relates to a liquid-clad micro-nano fiber long-period grating with the adjustable broadband. The liquid-clad micro-nano fiber long-period grating comprises a micro-nano fiber, a quartz capillary and cladding liquid. The micro-nano fiber and the cladding liquid are encapsulated in the quartz capillary; the micro-nano fiber is horizontally suspended at the center of the quartz capillary; and the space around the micro-nano fiber is filled with the cladding liquid. The micro-nano fiber is an intermediate nano-fiber portion after tapering of a single-mode fiber; and single-mode fibers are formed at the end portions of two sides extending out of the quartz capillary symmetrically after single-mode fiber tapering. A long-period grating is engraved at the middle part of the micro-nano fiber. Therefore, a problem of poor tunability of the long-period fiber grating in the prior art is solved.

The invention discloses a mid-infrared femtosecond pulse laser which comprises an ytterbium-doped fiber oscillator, a pulse stretcher, a spectrum shaping module, a crystal regenerative amplifier module, a pulse compressor, a second-order cascade nonlinear compressor module and a pulse internal difference frequency module which are arranged according to an optical path sequence. The ytterbium-doped fiber oscillator is used for generating initial laser pulses; the spectrum shaping module is used for performing spectrum shaping on the broadened laser pulse and generating a first laser pulse; the crystal regenerative amplifier module is used for amplifying the first laser pulse; the compressor module is used for carrying out nonlinear compression on the amplified and linearly compressed first laser pulse to generate a second laser pulse; the in-pulse difference frequency module is used for generating a third laser pulse of a middle infrared band from the second laser pulse through nonlinear conversion; and according to the invention, the structure of the laser is greatly simplified, the output efficiency of the pump pulse is improved, the wavelength tuning range of the mid-infrared femtosecond laser is expanded, and the cost of the mid-infrared femtosecond laser is reduced.

The invention discloses a Laguerre Gaussian optical parametric oscillator with tunable broadband topological charges. The oscillator comprises a nanosecond pulse laser, a beam shaping device, a coating cavity mirror, a periodically poled lithium niobate crystal, a temperature control device, a polarization element and a vector vortex wave plate, wherein the coating cavity mirror comprises a coating front cavity mirror and a coating rear cavity mirror which form a resonant cavity. The oscillator is advantaged in that relative positions of a vector vortex wave plate and the coating front cavitymirror meet the condition that a ratio of a concave mirror to a concave mirror is 1: 1, a self-reproduction cavity mode with smooth transition from a solid light beam to the hollow Laguerre Gaussian light beam is formed according to the imaging relation of the solid light beam and the hollow Laguerre Gaussian light beam, coupling efficiency of the cavity mode and the pump light is improved, intra-cavity loss is reduced, and finally high-efficiency, high-purity and wavelength and topological charge tunable Laguerre Gaussian light beam output is achieved.

The embodiment of the invention provides a hybrid integrated tunable outer cavity laser device and a wavelength tuning method. The laser device comprises an outer cavity and an output assembly, wherein the outer cavity comprises a reflection type semiconductor gain chip, a first collimation lens, a controlled optical grid filter, a converging lens and a semiconductor integrated chip, wherein a high-reflection film and an anti-reflection film are plated on two end faces of the reflection type semiconductor gain chip respectively; the first collimation lens, the controlled optical grid filter, the converging lens and the semiconductor integrated chip are arranged on the end face plated with the anti-reflection film of the reflection type semiconductor gain chip in sequence along a light path; a phase modulation region, a sampling optical grid region and a gain active region are integrated on the semiconductor gain chip, and are used for carrying out outer cavity phase modulation and control, cavity mode selective filtering and light power control respectively; the output assembly is arranged at a laser output side of the outer cavity and is used for outputting laser transmitted fromthe gain active region. The laser device is compact in structure, small in volume, small in coupling loss and relatively high in integration degree.

The invention discloses a microchip ridge waveguide laser, a tunable laser and a preparation method of the microchip ridge waveguide laser. According to the microchip ridge waveguide laser, by takinga ridge-shaped optical waveguide as a gain medium of the laser, the volume of a laser resonant cavity can be reduced, and the optical power density in the laser resonant cavity can be increased, so that the stable waveguide output can be realized; a traditional piezoelectric ceramic control manner is replaced with a temperature control manner, so that the disadvantage that a microchip is easily damaged through pressure control is overcome, and the microchip ridge waveguide laser has the advantages of high reliability and large wavelength turning range; the microchip ridge waveguide laser is prepared by virtue of a soft proton exchange method, so that the damage caused to lattices in crystals is reduced, and the laser frequency conversion efficiency is improved; and the microchip is prepared from waveguide, and two ends of the microchip are coated with films, so that a lens and a reflection mirror are not used, the numbers of components and parts required by the laser are reduced, the size and cost of the laser are greatly lowered, and the integration level and stability of a laser system can be improved.

A tunable two-micrometer pulse fiber laser device comprises a pulse pumping source with an output tail optical fiber, a single mode passive optical fiber, a band-pass filter, an isolator and an optical fiber amplifier, wherein the pulse pumping source with the output tail optical fiber, the single mode passive optical fiber, the band-pass filter, the isolator and the optical fiber amplifier are connected along an optical path in sequence. The tunable two-micrometer pulse fiber laser device achieves tuning output of pulses with wavelengths ranging from 1810 nanometers to 2170 nanometers by changing transmission wavelengths of the band-pass filter, has the advantages of being simple and compact in structure and the like, has a wavelength tuning range wider than that in the prior art and has wide application prospects in fields such as medical treatment and optoelectronic countermeasures.

The invention relates to the field of laser array coherent combination, and discloses a coherent combination system based on a mid-infrared optical parametric amplifier. The system is composed of a phase-controllable optical parametric amplifier laser beamlet module, an active phase control module and a beam combination and photoelectric detection feedback control module; the optical parameter amplifier laser beamlet comprises three parts, namely a pumping source, a seed source and an optical parameter amplifier; and, when the power density ratio of the seed light to the pump light in the optical parametric amplifier meets a certain condition, the phases of the seed light and the output light have a determined relation, the phase of the seed light is adjusted through a phase modulator arranged in a seed source so as to lock the phase between light beams of the mid-infrared band optical parametric amplifier array, and active phase-locked coherent combination of mid-infrared light wavesis achieved. The optical parametric amplifier beamlet in the system has the advantages of high single-path output power, high conversion efficiency, high polarization degree, wide wavelength tuning range, easiness in line width control and the like.

The invention discloses a double-frequency CARS measuring device and method based on a bound-state light soliton. The device at least comprises a femtosecond laser (1), an ultra-short pulse beam splitting adjusting part, a Stokes light pulse generating and transmitting light path, a pump light transmitting light path, a beam combiner (15) and a CARS microimaging system (16) which are connected insequence. Based on a soliton self-frequency-shift effect and a birefringence effect when an ultrashort pulse is transmitted in a high-nonlinearity photonic crystal fiber, a bound-state light soliton with overlapped time domains and separated wavelengths are generated. When the bound-state light soliton is used as a Stokes light pulse of a CARS system, the bound-state light soliton can simultaneously act with a pump light pulse to realize simultaneous excitation and detection of resonant frequencies of two molecules to be detected. In the invention, a system structure of the traditional CARS measurement system is simplified, system cost is reduced, and a chemical selective imaging capability and a multi-molecule simultaneous detection capability of the CARS system are improved.

The invention discloses a wavelength-tunable external cavity laser device. The device comprises a laser gain chip, a collimating lens, an optical path compensation sheet, a first adjustable filter, asecond adjustable filter, a partial reflector, an optical isolator, a converging lens and a receiving optical fiber which are sequentially arranged along an optical path; the partial reflecting surface of the partial reflector and the high reflecting surface at the back of the laser gain chip form a laser resonant cavity, and the external cavity laser device achieves tuning output of single-wavelength lasers by controlling the first adjustable filter and the second adjustable filter. The laser device can not only reduce the bandwidth of output wavelength but also enlarge the wavelength tuningrange and simultaneously lower the manufacturing difficulty of a standard distance. In addition, the coupling optical path of the whole external cavity laser device with the structure is relatively compact, and the miniaturization of the size of the whole laser device can be achieved.

Wavelength sweepable laser source is disclosed, wherein the laser source is a semiconductor laser source adapted for generating laser light at a lasing wavelength. The laser source comprises a substrate, a first reflector, and a second reflector. The first and second reflector together defines an optical cavity, and are arranged to support light oscillation in the optical cavity along an optical path in a direction normal to the substrate. The optical cavity comprises a void in the optical path. The second reflector is resiliently suspended by a suspension in a distance from the first reflector and having a rest position, the second reflector and suspension together defining a microelectromechanical MEMS oscillator. The MEMS oscillator has a resonance frequency and is adapted for oscillating the second reflector on either side of the rest position. The laser source further comprises electrical connections adapted for applying an electric field to the MEMS oscillator. Furthermore, a laser source system and a method of use of the laser source are disclosed

The embodiment of the invention discloses a manufacturing method of a laser and the laser. The manufacturing method comprises the following steps: sequentially dividing a first distributed feedback (DFB) region, a tuning region and a second DFB region on a substrate; respectively preparing selected area dielectric mask strip pairs on the first DFB region and the second DFB region, or preparing selected area dielectric mask strip pairs on the tuning region; sequentially epitaxially growing a lower respective limiting layer, a multi-quantum well layer and an upper respective limiting layer in a first DFB region and a tuning region which are provided with selected region dielectric mask strip pairs, and a second DFB region which is provided with selected region dielectric mask strip pairs, or in the first DFB region, the tuning region and the second DFB region which are provided with selected region dielectric mask strip pairs; the components of the multi-quantum well layer in the tuning region are respectively deviated from the components of the multi-quantum well layer in the first DFB region and the second DFB region; removing the selected area medium mask strip pairs; the laser manufactured through the manufacturing method is high in reliability, and the wavelength tuning range of the laser can be enlarged.

An improvement in a method of controlling lasing in a semiconductor laser fabricated in a photonic crystal laser having a plurality of holes into which a birefringent material with low refractive losses and low optical loses with controllable spatial refractive index orientation has been infiltrated comprises the step of rotating the molecular orientation or changing the physical orientation of the birefringent material infiltrated into the holes of the photonic crystal laser to switch cavity modes. The liquid crystal is aligned by use of an alignable photo addressable polymer layer adjacent to the liquid crystal. The cavity modes are optically switched within the laser without any requirement of external energy to maintain the lasing state of the laser, which allows its use as a memory element.

The disclosure provides a micro electro mechanical system for a vertical cavity surface emitting laser. The system comprises an injection electrode arranged at one end of the surface of an ohmic contact layer, a sacrificial layer arranged at the other end of the surface of the ohmic contact layer so as to be opposite to the injection electrode, an upper reflecting mirror layer arranged on the surface of the sacrificial layer, an a tuning electrode. A uniform fan blade cantilever structure is formed on the upper reflecting mirror layer, and the uniform fan blade cantilever structure comprises acircular reflecting mirror and a plurality of fan blade cantilevers; the plurality of fan blade cantilevers are spaced through air, and the sacrificial layer below the uniform fan blade cantilever structure is removed through corrosion, so that the uniform fan blade cantilever structure is suspended; and the tuning electrode is arranged on the surface of the upper reflecting mirror layer. The disclosure also provides a vertical cavity surface emitting laser and a preparation method thereof.

The invention discloses a terahertz source and application thereof. The terahertz source comprises a seed light source and a frequency modulation medium, wherein the seed light source generates seed light, the seed light enters the frequency modulation medium and then emits terahertz waves, the frequency modulation medium is a laser medium with Raman characteristic peaks, the frequency vout of theterahertz wave is equal to (c / [lambda]inp-c / [lambda]d) / 1, [lambda]d is equal to 1 / Raman characteristic peak position of the laser medium, [lambda]inp is the wavelength of the seed light, and the light speed c is 3.0*10<8> m / s. The terahertz source is small in size, few in parts, low in cost, capable of working at normal temperature and beneficial to improving application of terahertz waves in various fields, and obtains the terahertz waves based on light wave frequency conversion.

A tunable filter based on selective filling of quasi-dual-core photonic crystal fiber, characterized in that a quasi-dual-core structure is obtained by filling the air hole in the cladding of solid-core photonic crystal fiber with a high refractive index liquid, and the liquid column and quartz The core region constitutes two waveguides, which can realize the energy coupling of the optical field from the core to the liquid column when the refractive index matching coupling condition is met, and then generate a series of resonance peaks in the transmission spectrum. The device can be applied to the fields of multi-band tunable filtering, wavelength division multiplexing / demultiplexing, multi-parameter simultaneous sensing, vector sensing and the like. Compared with previously reported liquid-filled photonic crystal fiber filters, the present invention has a wide sensing range for external parameters, resonant peaks with different temperature and stress characteristics in multiple bands, and good linear tuning of resonant wavelengths. It has the characteristics of high resonance wavelength tuning rate, wide tuning range, low insertion loss, simple implementation, and high spectral stability.

The invention discloses a tunable laser, and relates to the field of optical communication devices. The tunable laser includes a silicon substrate, wherein the length direction, width direction and height direction of the silicon substrate are respectively defined as a first direction, a second direction, and a third direction; an optical input port, a first optical waveguide, a photonic crystal cavity, a second optical waveguide, an optical beam splitter, an optical emission port, an optical output port and an optical gain assembly which are formed on the silicon substrate. The optical inputport and the optical output port are connected through an optical fiber link to form a loop, and the optical gain assembly is arranged on the loop. According to the tunable laser, electrodes are respectively arranged at the two sides of a photonic crystal cavity in the second direction, or electrodes are arranged above the photonic crystal cavity in the third direction. The tunable laser providedby the invention is high in adjustment efficiency, large in tuning range, stable in output wavelength, small in structural size and beneficial to large-scale integration.