33results about How to "Changing the resonance wavelength" patented technology

The invention belongs to the field of microwave photonics, and discloses a system and method for frequency tunable microwave phase shifting. The method comprises the following steps that after a continuous light carrier is splitted, one beam of the continuous light carrier is processed by a MZ Mach-zehnder, and double-sideband optical signals restrained by the carrier are produced; the other beam of the continuous light carrier is processed by a phase modulator, and phase-shifted light carrier signals are produced; two beams of light signals are combined in a wave mode, one one-step sideband is removed through a tunable micro-ring filter in a filtering mode, a frequency-moved carrier signal and a phase-shifted carrier signal are obtained, photovoltaic conversion is carried out through a photoelectric detector, and a phase shift microwave electrical signal is produced; the resonant frequency of the tunable micro-ring filter is equal to any one-step sideband of the two one-step sidebands output by the MZ Mach-zehnder by changing the frequency of an input voltage drive signal and the resonant wavelength of the tunable micro-ring filter, and the frequency of the phase shift microwave signal is changed. The system and method for the frequency tunable microwave phase shifting is stable in output performance, fast in phase shift adjusting response, small in output microwave range fluctuation and continuously adjustable in wide frequency range.

The invention provides a novel photoelectric detector with adjustable response spectrum. The novel photoelectric detector is characterized in that the device structure sequentially comprises an insulation substrate, a gate, a first insulation isolation layer, a conductive channel layer, a metal source-drain, a second insulation isolation layer, a plasmon metal nanometer structure, an electro-optical crystal coverage layer and a transparent leading-out electrode from bottom to top. The refractive index of the electro-optical crystal coverage layer is controlled by an externally-applied voltage, so that the refractive index of a coverage substance is changed with the change of the external voltage to further control plasmon resonant wavelength of the metal nanometer structure and response wavelength of the detector. In the detector device structure, the spectrum can be regulated by the voltage, miniaturization and microminiaturization are facilitated, and the novel photoelectric detector has good application prospect in the field of a photoelectric device and optical communication.

The invention discloses a microwave photonic band stop filter based on a Microring-Mach Zehnder interference (MR-MZI) structure, which comprises a semiconductor laser, a polarization controller, a phase modulator, an optical band pass filter, an MR-MZI integrated optical filter unit and a photoelectric detector. Narrow bandwidth filter is realized through adjusting the coupling interval between microring resonators in the MR-MZI integrated optical filter unit; through adjusting the bias voltage of each heating electrode in the MR-MZI integrated optical filter unit, the amplitude and the phase of signals are regulated; the amplitude response and the phase response of the microring are used for being combined with the MZI structure in the MR-MZI integrated optical filter unit to generate fully destructive interference, and an ultra high inhibition ratio is realized. According to the microwave photonic band stop filter provided by the invention, on the basis of the narrow bandwidth, the ultra high inhibition ratio is realized, and the microwave photonic band stop filter performance is improved.

The invention relates to a surface nano grating-based wavelength tunable vertical cavity surface emitting laser and a preparation method, which belong to the field of semiconductor photoelectronic devices. The laser has an inner cavity contact laminated structure; a positive electrode layer (1) is arranged on a P-type ohmic contact layer (5); an air-gap layer (12), a gallium arsenide layer (2a), and a gallium aluminum arsenide layer (2b) are arranged above the ohmic contact layer (5) in turn; a gallium aluminum arsenide oxidation current limitation layer (6), an active region (7), an n-type gallium aluminum arsenide layer (8a), an n-type gallium arsenide (8b), an n-type gallium arsenide substrate (10), and a substrate electrode layer (11) are formed below the ohmic contact layer (5) in turn; and a nano grating (15) is positioned on the surface of the gallium arsenide layer (2a). The thickness of the air-gas layer can be subjected to mechanical adjustment of an electrostatic force and the like, so that photon phase change can be transmitted in the resonant cavity of a laser and an outputted light beam passes through the nano grating (15) immediately; therefore, a wavelength and polarization can be simultaneously controlled.

The invention discloses an optical bandpass filter based on a double microring-Mach Zehnder interference structure. The optical bandpass filter is composed of a first multi-mode interference coupler, a second multi-mode interference coupler, a third multi-mode interference coupler, a first coupling grating, a second coupling grating, a first heating electrode, a second heating electrode, a third heating electrode, a fourth heating electrode, a first upload-download type micro ring, and a second upload-download type micro ring. According to the invention, on the basis of the design of the coupling states of two upload-download type micro rings, fully destructive interference is introduced based on a cascaded adjustable Mach Zehnder interference (MZI) structure; amplitude regulation is realized by adjusting the bias voltage on the heating electrode of the MZI1, so that amplitudes of passband external light signals of an upper arm and a lower arm becomes identical; and phase regulation is realized by adjusting the bias voltage on the heating electrode of the MZI2, so that phases of passband external light signals of the upper arm and the lower arm are opposite. Therefore, the extinction ratio of the filter increases under the circumstance that the passband insertion loss is not increased. The provided optical bandpass filter has advantages of narrow bandwidth, high extinction ratio, and low insertion loss.

The invention discloses a multi-layer wrapped quantum dot core-shell composite particle and a preparation method of the core-shell composite particle. The preparation method comprises wrapping a transparent inorganic insulating layer on the surface of a quantum dot to obtain an inorganic insulating layer wrapped quantum dot; connecting the inorganic insulating layer with a reductive group and performing surface modification to obtain a surface activated inorganic insulating layer wrapped quantum dot; and wrapping a precious-metal nano-particle layer on the surface of the surface activated inorganic insulating layer wrapped quantum dot to obtain the multi-layer wrapped quantum dot core-shell composite particle. The multi-layer wrapped quantum dot core-shell composite particle has characteristics of good stability, low biological toxicity, strong fluorescence intensity and high quantum efficiency. The reaction for preparing the multi-layer wrapped quantum dot core-shell composite particle is performed in a solution; high temperature and high pressure are not needed during the whole process; the operation is simple; the yield is high; a large number of multi-layer wrapped quantum dot core-shell composite particles can be prepared at a time; wrapping layers with different thickness can be obtained by controlling the reaction conditions and reaction parameters; and thus the multi-layer wrapped quantum dot core-shell composite particle has a good application prospect.

The invention discloses a reconfigurable guiding logic device based on a multiple-wavelength single-waveguide multiple-ring cascade structure, which is particularly applicable to the future optical information processing field. The reconfigurable guiding logic device based on the multiple-wavelength single-waveguide multiple-ring cascade structure is formed by n logic device arithmetic elements and a straight waveguide, wherein each logic arithmetic element is formed by N micro-ring MRRs (Multiple Response Resolvers); each micro-ring MRR is coupled with a wire waveguide. According to the device provided by the invention, the natural characteristic of light is utilized, so that a large amount of information can be processed at high speed; meanwhile, the mature process technology is utilized, so that the device is high in integration level, small in size, low in power consumption, good in expansibility, and convenient to integrate with electric components, so as to be expected to play an important role in optical information processing.

The invention relates to a polarization-independent filter based on a guided-mode resonance liquid crystal structure. The polarization-independent filter comprises a first electrode layer, a grating layer, a second electrode layer and a substrate layer. A voltage-adjustable power supply is connected between the first electrode layer and the second electrode layer and is used for adjusting the voltage on nanometer indium tin metal oxide (ITO) of the first electrode layer and the second electrode layer of two ends of the grating layer to coincide the wavelengths of filter waves of a transverse electric mode (TE) and a transverse magnetic mode (TM) so as to realize polarization independent effect. The voltage on the ITO (indium tin metal oxide) at two ends of the crystal can be adjusted, so that resonance wavelengths of different polarization states can be changed, the wavelengths of the filter waves of the transverse electric mode (TE) and the transverse magnetic mode (TM) can be coincident, and adjustable polarization independent effect of the filter can be realized.

The invention discloses a track type micro-ring 2*4 thermo-optic switch prepared based on SOI material. The switch comprises a straight waveguide, a track type micro-ring waveguide prepared based on SOI material, and a thermal electrode arranged at the top layer. For the track type micro-ring waveguide, a bending waveguide and a short straight waveguide forms a closed track; coupling zones are formed between the track type micro-ring waveguide and direct waveguides; and the intersection parts of the direct waveguides employ multimode waveguide intersected structures. A digital electrical signal loaded by the thermal electrode arranged at the top layer is applied to realize rapid switching of optical channels. Therefore, simultaneous switching of the multi-input and multi-output optical signals can be realized; and the track type micro-ring 2*4 thermo-optic switch can be applied to working state detection of unit devices in the optical switch array, the optical routing, the optical logic gate design, and the integrated optical path.

The invention discloses an odd-even check technology in the technical field of optical communication. An electro-optic odd-even checker is formed by N microring resonators (MRRs) and two bent nanowire waveguides, wherein the MRRs are made of semiconducting material on insulators, each MRR is respectively coupled with the two nanowire waveguides, and a spacer or an insulator is arranged between every two adjacent MRRs and can prevent thermal crosstalk between the two adjacent MRRs. Compared with an electric odd-even checker, the electro-optic odd-even checker has the advantages of being small in size, low in power consumption, high in speed, good in expansibility and capable of being integrated with an electric element conveniently, and has excellent application prospects in an optical communication network.

The invention relates to a current detector based on a metal-dielectric-metal waveguide. The current detector comprises a substrate, and a first metal plate, a second metal plate and electrodes whichare arranged on the substrate. The first metal plate and the second metal plate are arranged in parallel, and a gap is formed between the first metal plate and the second metal plate, so as to form ametal-dielectric-metal waveguide. The electrodes are connected to the two ends of the metal plate on either side of the gap. A cavity is formed in the first metal plate, and a magnetic fluid is arranged in the cavity. When a current to be detected flows through the first metal plate or the second metal plate, a magnetic field is generated at the magnetic fluid to change the refractive index of themagnetic fluid and further change the resonance wavelength of the cavity, and the current intensity can be detected by detecting the change of the resonance wavelength. According to the current detector, either metal plate forming the metal-dielectric-metal waveguide is used for conducting a current and generating a magnetic field, so that the current detector has the advantages of small structural size, high detection sensitivity, wide amplitude of current intensity detection, and the like.

The invention discloses a narrow-band metasurface device, and the device comprises a groove antenna metasurface layer, a buffer dielectric layer, an adjustable dielectric layer group and a substrate layer which are sequentially arranged from top to bottom. The adjustable dielectric layer group comprises an adjustable dielectric layer and transparent electrode layers arranged on the upper surface and the lower surface of the adjustable dielectric layer; the groove antenna metasurface layer comprises a groove antenna metasurface structure; the groove antenna metasurface structure comprises metasurface antenna units which are periodically distributed, grooves are formed in the metasurface antenna units, and the aperture opening ratio of the metasurface antenna units is made to be greater than0.7. The refractive index of the buffer dielectric layer and the refractive index of the substrate layer are less than the refractive index of the adjustable dielectric layer. The reflectivity curveof the device provided by the invention has an extremely narrow bandwidth, and the full width at half maximum of the reflection peak is within 2nm; meanwhile, the change of the adjustable dielectric layer in the structure can change the resonance wavelength of a reflectivity curve, so the reflectivity curve can change in a visible light range or a larger range, ultrahigh efficiency and extremely narrow bandwidth are kept, and the structure can be applied to the fields of spectrum detection, spectrum inspection and the like.

The invention provides a Fabry-Perot cavity filter for dynamic color regulation and control and a preparation method and a tuning method. The Fabry-Perot cavity filter sequentially comprises a first metal film layer, a second non-conductive dielectric layer, a third transparent conductive oxide layer, a fourth metal layer and a fifth substrate layer from top to bottom, wherein the second non-conductive dielectric layer is used as a barrier layer to block metal ion migration after electrochemical metallization of a material with a dielectric constant tending to 0; the third transparent conductive oxide layer is made of a material with a dielectric constant tending to 0; and the refractive index can be changed under the action of an electric field, so that the refractive index of the Fabry-Perot cavity is adjusted. According to the invention, the effective refractive index of the ENZ material is changed based on the ECM effect, so that the resonance wavelength of the FP cavity is changed, the problem can be effectively solved, and the resonance condition can be memorized while the voltage is removed.

The invention relates to the field of two-dimensional material photothermal characteristic detection, and particularly provides a resonant cavity type two-dimensional material photothermal effect measuring device. During measurement, the two-dimensional material is arranged on a sensitive material part, the two-dimensional material absorbs the energy of incident light to generate heat, the sensitive material part absorbs heat to increase the temperature, the refractive index of the sensitive material part is changed, the resonant wavelength of the resonant cavity is changed, and the photothermal characteristic of the two-dimensional material is determined according to the relationship between the intensity of the incident light and the resonant wavelength. Since the resonance wavelength ofthe resonant cavity is very sensitive to the refractive index of the material in the resonant cavity, the device has the advantage of high detection sensitivity of the photothermal effect of the two-dimensional material. The light path is based on the metal-medium-metal waveguide, and the light path is simple. In addition, when the photothermal effect of the two-dimensional material is tested, only the two-dimensional material to be tested needs to be arranged on the sensitive material part, and the experimental operation is simple.

The invention relates to a sound wave detector and system based on the acousto-optic effect and particularly relates to the field of sound wave detection. When the sound wave detector detects sound waves, the sound wave detector is arranged under an illumination condition, a semiconductor layer is made of an acousto-optic material, so the optical refractive index of the semiconductor layer can bechanged under the action of sound waves, furthermore, coupling between the first metal layer and the second metal layer is changed, so resonance wavelength between the first metal layer and the secondmetal layer is changed, through the change of the resonance wavelength between the first metal layer and the second metal layer and the corresponding relation between the changed resonance wavelengthand the sound waves, the sound waves to be measured can be directly obtained, as the sound waves are characterized through optical resonance, loss of the sound waves can be reduced, and measurement of the sound waves is more accurate.

The invention provides a graphene waveguide type terahertz pulse energy detection device. The device is characterized in that a first fixing part and a second fixing part are arranged on a substrate,a first waveguide part, a sensing part and a second waveguide part are sequentially connected to form a waveguide structure, and one end of the first waveguide part of the waveguide structure is fixedon the first fixing part; and one end of the second waveguide part of the waveguide structure is fixed to the second fixing part, the waveguide structure is in a suspended state, and the first waveguide part, the second waveguide part and the sensing part are made of graphene. During application, the terahertz source emits terahertz waves and couples the terahertz waves into the first waveguide part, the terahertz waves are propagated along the waveguide structure, and the terahertz detector detects a transmission terahertz spectrum propagated to the second waveguide part; the terahertz pulseto be detected irradiates the sensing part, and terahertz pulse energy detection is realized by measuring the change of the resonance wavelength in the transmission terahertz spectrum. The detectiondevice has the advantage of high terahertz pulse energy detection sensitivity.

The invention relates to the technical field of hydrogen detection, in particular to a hydrogen detector based on precious metal coupling, which comprises a substrate, an elastic layer and a sensing unit, the elastic layer is arranged on the substrate, the sensing unit is periodically arranged on the elastic layer, the sensing unit comprises a palladium block, a first precious metal part and a second precious metal part, the palladium block is arranged on the elastic layer, and the first precious metal part is arranged on the first precious metal part. The first precious metal part and the second precious metal part are arranged on the palladium block, and a gap is formed between the first precious metal part and the second precious metal part. During application, in a to-be-detected hydrogen environment, the continuous spectrum light source irradiates the first noble metal part and the second noble metal part, the palladium block adsorbs hydrogen to generate expansion, and hydrogen or hydrogen concentration detection is realized through movement of resonant wavelength. In the invention, the size of the palladium block for adsorbing hydrogen is large, and the sizes of the first noble metal part and the second noble metal part which cause the resonance wavelength to move are small, so that the adjustment force of the hydrogen on the resonance wavelength is large, and the hydrogen detection with higher sensitivity is realized.