57 results about "Distributed feedback laser" patented technology

The invention provides a distributed feedback laser with a double-layer grating structure, and relates to the technical field of lasers, the laser forms an InGaAlAs multi-quantum well active region, an upper sampling grating layer and a lower phase shift grating layer on an n-type InP substrate in sequence, the upper grating layer is designed based on a reconstruction equivalent chirp technology, and the lower phase shift grating layer is designed based on a reconstruction equivalent chirp technology. Two sections of asymmetric modulation areas with sampling periods linearly gradually changing in opposite directions are arranged in the axial direction of the resonant cavity, and the lower grating layer is a quarter-wave phase shift grating matched with the period of the upper seed grating. Through the synergistic effect of equivalent phase modulation and phase shift generated by the double-layer grating, the photon density distribution in the cavity can be improved, the longitudinal space hole burning effect can be weakened, the sensitivity to end face phase fluctuation can be reduced, high single-mode power and large modulation bandwidth can be realized in a wide temperature range, and the double-layer grating is suitable for a high-speed optical communication and coarse wavelength division multiplexing transmission system.

The invention provides an on-chip integrated laser light source and an optical coupling integration method thereof.The on-chip integrated laser light source comprises a silicon optical substrate and a light source chip assembly integrated on the silicon optical substrate, and the silicon optical substrate comprises an optical signal transmission waveguide; the light source chip assembly comprises a surface-emitting distributed feedback laser chip so as to generate laser beams emitted in the direction perpendicular to the surface of the chip. The on-chip integrated laser light source further comprises a grating coupling structure arranged between the surface emission distributed feedback laser chip and the optical signal transmission waveguide. The light-emitting surface of the surface-emitting distributed feedback laser chip is arranged towards the silicon light substrate, and a laser beam generated by the surface-emitting distributed feedback laser chip is directly projected and coupled into the light signal transmission waveguide through the grating coupling structure; the surface-emitting distributed feedback laser chip is fixedly combined on the silicon optical substrate through a flip chip technology, so that the high-precision end face alignment requirement of the heterogeneous integrated waveguide is converted into high-efficiency grating coupling based on a surface light emitting mode. In this way, harsh end face coupling is converted into efficient grating coupling.

The application discloses a phase-sensitive pre-amplification method based on an electro-absorption modulated laser, and is applied to a star-ground laser communication system receiving end. A distributed feedback laser in the electro-absorption modulated laser amplifies weak pump light after long distance transmission, and generates idler light under the nonlinear effect of a laser cavity; an electro-absorption modulator in the electro-absorption modulated laser detects phase error information between signal light, pump light and idler light, and constructs an optical injection phase-locked loop through a feedback loop, so that stable control of the three-wave phase relationship is realized. Under the phase stability condition, the output light of the electro-absorption modulated laser is fed into a later-stage nonlinear medium to complete phase-sensitive pre-amplification. The phase-sensitive pre-amplification method based on the electro-absorption modulated laser has the advantages of simple structure and easy integration, can realize pump light amplification, idler light generation and phase error suppression under the condition of weak pump light, and effectively improves the receiving sensitivity performance of the star-ground laser communication system.

The application discloses a kind of switch cabinet partial discharge monitoring device and method, wherein, method includes: when the partial discharge of switch cabinet cabinet wall occurs, vibration signal is generated;Distributed feedback laser is affected by vibration signal, deformation occurs, cause the wavelength of distributed feedback laser to change;Interferometer receives the laser emitted by distributed feedback laser, and the wavelength change of laser is converted into phase change, by monitoring phase change to realize the partial discharge monitoring of switch cabinet cabinet wall.The pin is made of rigid material, is easily affected by the vibration generated by the partial discharge of switch cabinet cabinet wall, so that the DFB laser inside pin is affected by vibration, the wavelength of output laser changes, by converting the monitoring of vibration signal into the monitoring of laser signal, avoid the interference caused by electromagnetic influence and noise influence in the environment when monitoring electromagnetic wave and sound wave in conventional means, improve the reliability of the partial discharge monitoring of switch cabinet cabinet wall.

Apparatuses, methods, and systems for a modulated laser are disclosed. The modulated laser includes a substrate including a plurality of laser segments, a first laser segment comprising a DC electrode, a second laser segment comprising an AC electrode, an isolation barrier formed between the first laser segment and the second laser segment, and a modulated laser cavity spanning from a rear face to a front face of the modulated laser inclusive of the plurality of laser segments, wherein a primary injection current supporting stimulated emission at a desired optical output power out of the front face of the modulated laser is generated when a DC bias is applied to the DC electrode, and wherein a carrier signal of the modulated laser is modulated when an AC signal is applied to the AC electrode, wherein the AC bias is independent of the DC bias.

In one embodiment, a distributed feedback laser includes a laser comprising a waveguide, the waveguide having a variable width from a first end to a second end, the laser to generate optical energy of a plurality of lasing wavelengths. Other embodiments are described and claimed.

The present invention provides an integrated distributed optical fiber sensing system comprising: an on-chip integrated laser (1), an injection locking unit (3), a distributed feedback laser (2), a semiconductor optical amplifier (5), an optical circulator (6), a sensing optical fiber (7), and a coherent detection unit (4), wherein the on-chip integrated unit (10a) is obtained by on-chip integration of the injection locking unit (3) and the coherent detection unit (4).

According to the present invention, techniques for high power gallium and nitrogen containing laser diode devices are provided. Such high-power devices include straight lasers, tapered lasers, distributed feedback lasers, distributed Bragg reflector laser devices, and power amplifier devices configured with improved mode quality, each of which can be modulated using a modulator device.

To provide an optical integrated laser element capable of reducing the occurrence of a mode hop while increasing the intensity of an output laser beam.SOLUTION: The optical integrated laser element includes a distributed feedback laser part, a semiconductor optical amplification part, and a high reflection film. The distributed feedback laser portion includes a diffraction grating and a first optical waveguide. The first optical waveguide is provided along the diffraction grating and has a gain. The semiconductor optical amplifier unit is provided on the substrate, is provided on a first side of the distributed-feedback laser unit, is optically connected to the first optical waveguide, has a gain, and includes a second optical waveguide having a width wider than a width of the first optical waveguide. The high reflection film is provided on an end surface on a second side opposite to the first side of the distributed feedback laser portion. The distributed feedback laser portion and the semiconductor optical amplification portion are integrated on the substrate. The length of the first optical waveguide in the optical waveguide direction is 1000 μm or less, and the length of the second optical waveguide in the optical waveguide direction is 1.5 times or more and 7 times or less the length of the first optical waveguide in the optical waveguide direction.SELECTED DRAWING: Figure 1

The application belongs to the technical field of optical fiber gas sensing, and discloses a kind of optical fiber photoacoustic gas sensing system and method suitable for low pressure environment.System includes programmable logic gate array circuit, distributed feedback laser, laser transmission optical fiber, optical fiber photoacoustic sensing probe, super radiation emitting diode light source, optical fiber circulator and spectrometer.According to the linear relationship between the cantilever beam resonance frequency and the ambient pressure, the gas pressure is monitored, and the acoustic sensitivity at the resonance of the cantilever beam is enhanced at low pressure to compensate for the attenuation of the signal in the photoacoustic excitation process.Combined with the measured pressure of the cantilever beam, the sensitivity is corrected, so as to realize the high precision and high sensitivity detection of trace gas under low pressure environment.The system only uses a single cantilever beam and a single demodulator, and has the functions of pressure and gas concentration detection, and can realize accurate detection of trace gas in a changing pressure environment.The all-fiber scheme has the characteristics of intrinsic safety, and is easy to remote measure and multi-point network detection.

The application discloses a Rydberg atom electric field sensing device and system, and is applied to the field of quantum sensing.The device comprises an atom chamber, a first distributed feedback laser and a second distributed feedback laser.The first distributed feedback laser and the second distributed feedback laser each comprise a laser source resonant cavity formed inside.The first distributed feedback laser and the second distributed feedback laser generate laser based on optical feedback and optical amplification of the laser source resonant cavity inside each of them, and the laser is used as probe light and pump light respectively, and enters from one side of the atom chamber, so that the atoms in the atom chamber reach the excited state and the Rydberg state in turn.The application uses the distributed feedback laser as the pump light and the probe light for exciting the Rydberg atom, provides a miniaturized light source for the Rydberg atom electric field sensing device, improves the integration of the device, has the advantages of miniaturization, is easy to move, is suitable for a harsh outdoor environment, and can realize large-scale integration of chips.

The application provides a frequency stabilized laser device and a quantum communication system, and relates to the technical field of lasers.The frequency stabilized laser device comprises: a first distributed feedback laser for generating a first laser; a second distributed feedback laser for generating a second laser; an inner closed loop for cavity mode locking of the first distributed feedback laser and the second distributed feedback laser respectively, so as to suppress noise and cavity length disturbance and complete short-term stable regulation; and an outer closed loop for beat frequency processing of the first laser and the second laser according to a reference frequency, so that the frequencies of the first laser and the second laser remain stable, the long-term thermal drift of the first distributed feedback laser and the second distributed feedback laser is suppressed, and short-term and long-term stability is unified.The application can solve the technical problems that the existing laser cannot simultaneously realize short-term low noise and long-term low drift, the stable cavity effect is poor, and frequency difference monitoring is difficult, and realizes the unification of short-term stability and long-term stability of the laser signal.

An apparatus comprising (a) a distributed feedback laser (DFL), (b) a photonic integrated circuit (PIC) comprising a PIC trench within which the DFL is positioned, (c) PIC trench contacts formed within the PIC trench, (d) an adapter wherein the adapter is attached to a region of the PIC and the DFL using one or more bonding elements, and (e) one or more traps, and an adapter for receiving excess bonding material formed during attachment of the adapter to at least one of the areas of the DFL and the PIC, and preventing the excess bonding material from electrically coupling the DFL distal contact to the DFL proximal contact.

The application discloses a kind of directly modulated multi-section tunable laser, which is composed of multiple laser units in series, both ends of the tunable laser are coated with anti-reflection film, the front end of the first laser unit is integrated with an optical amplifier, the sampling grating periods of adjacent laser units are different, and the lasing wavelength difference is 2-5 nm;The laser unit includes: a laser light-emitting active gain region and a feedback compensation region arranged before and after the laser light-emitting active gain region, the laser light-emitting active gain region is inserted with an equivalent π phase shift sampling grating structure through the reconfiguration-equivalent chirp technology, and the feedback compensation region adopts a uniform sampling grating period, which is different from the sampling period of the sampling grating structure of the laser light-emitting active gain region.This tunable laser is beneficial to improve the modulation rate of the laser and the single-mode output characteristics of the laser, and simultaneously cascades multiple distributed feedback laser units to realize wavelength tuning coverage.

The invention discloses a flat low-noise multi-wavelength laser generation system and method based on a Brillouin cavity. The system comprises a multi-wavelength pumping laser generation branch, a Brillouin optical fiber ring cavity and a frequency shift injection locking branch. The multi-wavelength pumping laser generation branch is used for generating and outputting flat multi-wavelength pumping laser and comprises a first distributed feedback laser, a first polarization controller, a first optical fiber circulator, a first multi-wavelength generator and a spectrum shaper; and the Brillouin optical fiber ring cavity is connected with the multi-wavelength pumping laser generation branch and the frequency shift injection locking branch through a second circulator, and is used for generating and finally outputting multi-wavelength Brillouin laser. The invention generates multi-wavelength laser with the advantages of low noise, flat spectrum and the like, and is suitable for application scenes of low-phase noise signal generation, high-dynamic range signal processing and the like in a microwave photon system.

The application relates to the technical field of electro-optical frequency comb generation, and discloses a super-narrow-line-width, wide-band, flexible-repetition-frequency and adjustable electro-optical comb generation system and method, which comprises a pump laser generation branch, a fiber ring cavity, and a frequency shift injection locking branch.The pump laser generation branch comprises a distributed feedback laser, a first polarization controller and a first circulator; the fiber ring cavity comprises a second circulator, a Brillouin gain fiber, a fiber delay line, a fiber coupler, a second polarization controller, an electro-optical modulator, a dispersion compensation fiber, an optical amplifier, a flat filter and an isolator; and the frequency shift injection locking branch comprises a narrow-bandwidth filter, a polarization controller and a frequency shifter.The electro-optical frequency comb generation device of the application has a novel structure, realizes super-narrow-line-width, wide-band, flexible-repetition-frequency and adjustable electro-optical comb output, solves the limitations of narrow bandwidth and wide comb line width of a traditional electro-optical frequency comb generated based on electro-optical modulation, and does not need complex active optoelectronic feedback to maintain stable operation of the system.

A method of manufacturing a distributed feedback laser apparatus has the steps: fabricating (512) a plurality of distributed feedback lasers on a wafer substrate, each laser comprising a respective laser cavity; on-wafer testing (514) the lasers to generate respective lasers' parametric test results (516); determining (518), using the respective lasers' parametric test results, different respective fabrication modifications (520) customised to respective lasers to adjust each respective laser cavity nonuniformly to compensate for variation in the parametric test results; and performing (522) one or more wafer-level fabrication step comprising lithographic patterning on the wafer substrate having the plurality of the lasers fabricated on it, to apply the different respective fabrication modifications to the respective lasers.

The embodiment of the invention discloses a distributed feedback laser and a distributed feedback laser preparation method, the distributed feedback laser comprises a laser main body, a first dielectric layer, a heating resistor and a heating electrode, and the distributed feedback laser can realize the working function of the distributed feedback laser through a ridge waveguide on a semiconductor function lamination structure. In the working process of the distributed feedback laser, the heating resistor can be powered on through the heating electrode, current flows through the heating resistor, the heating resistor can generate heat under the resistance effect of the heating resistor, and the heat can directly act on the active area of the semiconductor function laminated structure through the ridge waveguide. According to the distributed feedback laser provided by the embodiment of the invention, the heating resistor is directly positioned above the ridge waveguide and can be further positioned right above the active region, the heat transfer path is shortest, and the heat loss is small, so that the heat efficiency is extremely high, and the response speed is far higher than that of a TEC and back integrated heating scheme.

The invention provides a distributed reflector (DR) semiconductor laser, comprising two cavity sections which are composed of a distributed feedback (DFB) laser section and a distributed Bragg reflector (DBR) section.

The invention discloses an optical gyroscope based on photon orbital angular momentum, which belongs to the field of photoelectric sensing and comprises a thin-film lithium niobate integrated optical chip, and a distributed feedback laser and a photoelectric detector are integrated on the thin-film lithium niobate integrated optical chip in a hybrid manner. And a photon orbital angular momentum demodulator and a photoelectric detector array are packaged outside the thin film lithium niobate integrated optical chip. An annular cavity structure with a grating is integrated on the thin film lithium niobate integrated optical chip, so that a function of radiating a photon orbital angular momentum mode from an in-ring resonance echo wall mode from the grating is realized. Different from a traditional gyro chip which observes the change of the angular velocity based on the Sagnac phase change, the micro-ring integrated on the thin film lithium niobate chip can cause the change of a photon orbital angular momentum mode during rotation, and the corresponding angular velocity during rotation of the ring is measured by identifying the change of the photon orbital angular momentum. The scheme has the advantages of higher precision and integration level and no need of using an optical fiber ring.

The invention provides a manufacturing method of an antimonide distributed feedback laser. The manufacturing method comprises the following steps: S1, forming an N-type first InAs buffer layer on a substrate; s2, forming an N-type lower InAsSb limiting layer on the N-type first InAs buffer layer; s3, forming an N type lower InAlAsSb waveguide layer on the N type lower InAsSb limiting layer; s4, an InGaAs / InAlGaAsSb quantum well layer is formed on the N type lower InAlAsSb waveguide layer; s5, a P type upper InAlAsSb waveguide layer is formed on the InGaAs / InAlGaAsSb quantum well layer; s6, forming a P type upper InAsSb limiting layer on the P type upper InAlAsSb waveguide layer; s7, forming a second P-type InAs buffer layer on the upper P-type InAsSb limiting layer; s8, forming a P-type corrosion barrier layer on the P-type second InAs buffer layer; s9, forming a P-type grating layer on the P-type corrosion barrier layer; s10, forming a P-type barrier layer on the P-type grating layer; s11, forming a P-type ohmic contact layer on the P-type barrier layer; wherein the steps from S1 to S11 are executed by adopting an MOCVD (Metal Organic Chemical Vapor Deposition) method. The invention also provides an antimonide distributed feedback laser manufactured by using the manufacturing method.

The invention provides a distributed feedback laser and a performance verification method thereof, and a grating structure, the grating structure of the distributed feedback laser comprises a first grating section and a second grating section, a phase shift grating is arranged between the first grating section and the second grating section, and the grating transverse width of the first grating section is smaller than the grating transverse width of the second grating section. The coupling coefficient of the first grating section is smaller than that of the second grating section. The distributed feedback laser comprises a high-reflection film coating end and an anti-reflection film coating end, the first grating section is close to the high-reflection film coating end, and the second grating section is close to the anti-reflection film coating end. The grating sections with different coupling coefficients are designed in a segmented manner, and the phase shift grating is introduced between the grating sections, so that the photon distribution can be homogenized, the longitudinal space hole burning effect is effectively inhibited, the line width is narrowed, and the single longitudinal mode stability is enhanced.

The invention discloses a distributed feedback laser based on an asymmetric sampling grating and a manufacturing method thereof, and belongs to the technical field of laser, in a grating structure of the laser, the position of equivalent pi phase shift deviates from the center of a cavity, and the duty ratio of the sampling grating, namely the ratio of the length of a sampling window to a sampling period, is less than 0.5. According to the invention, the reconstruction equivalent chirp technology is adopted, and the design of asymmetric phase shift and asymmetric coupling coefficient is combined, so that the forward output power is remarkably improved. In the structure of the laser, asymmetric regulation and control of photon density distribution are realized by optimizing the phase shift position and the duty ratio of the sampling grating, so that the forward output power is improved on the premise of keeping the stability of a single longitudinal mode. According to the method, the sampling structure is prepared by adopting a micron-sized photoetching technology, so that the dependence on high-precision electron beam photoetching is reduced, and the manufacturing tolerance and the cost effectiveness are improved. Experimental results show that the laser is stable in spectrum when working at the C wave band, and the side mode rejection ratio is higher than 50 dB.

The application discloses an electrically pumped complex-coupled distributed feedback laser resonant cavity and a laser, and the laser resonant cavity comprises a gain material layer; a first doped cladding buffer layer is arranged above the gain material layer, the first doped cladding buffer layer is formed into a waveguide ridge with a middle protrusion through etching, a surface layer of a remaining area on both sides of the waveguide ridge is provided with a dielectric isolation layer, and a top surface of the dielectric isolation layer is a plane; a second doped cladding buffer layer is arranged below the gain material layer; a first Bragg array is arranged on a surface layer of both sidewalls or both sides of the remaining area of the waveguide ridge; a second Bragg array is arranged on the dielectric isolation layer; a first electrode is arranged on a top surface of the waveguide ridge; and a second electrode is arranged on a bottom surface of the second doped cladding buffer layer. When the current is injected through the N-type metal electrode and the P-type metal electrode and the current density of the laser reaches above a threshold value, the laser can realize stable single-frequency laser output and has strong resistance to external echoes.

The application discloses a weak light signal heterodyne coherent detection system based on wavelet transform and belongs to the technical field of microwave photonics. The detection system comprises a distributed feedback laser, a 90 / 10 coupler, a 50 / 50 coupler, an optical attenuator, an acousto-optic modulator, an arbitrary signal generator, a photodetector, an amplifier, a band-pass filter, an oscilloscope and a data processing unit. The application utilizes the low-noise amplification characteristics of the coherent detection technology, realizes an ideal signal-to-noise ratio through the interference effect of signal light and local oscillator light, and gets rid of the dependence of single-photon detection on an ultralow-temperature environment. Meanwhile, a data processing method combining variational mode decomposition, continuous wavelet transform, cross-correlation analysis and phase analysis is adopted to extract single-photon signals from noisy signals, so that the weak signals reaching the single-photon level can be efficiently detected at room temperature, and the application range of single-photon detection devices is expanded.

The invention relates to the technical field of photoelectrons, and discloses a distributed feedback laser and a preparation method thereof, and the distributed feedback laser comprises a substrate layer, a separation limiting heterostructure, a coupling grating layer, a dielectric layer, an anode and a cathode. Bragg gratings are sectionally arranged on the side wall of the ridge waveguide of the coupling grating layer along the cavity length, each grating at least comprises two grating sections with different coupling coefficients, and a quarter-wavelength phase shift region is arranged at the center of the cavity; the end face of the cavity can adopt an anti-reflection or high-reflection coating film combination. The coupling coefficient and length ratio of each section is determined according to the end face reflectivity, target coupling coefficient distribution is achieved by changing parameters such as the side wall etching depth, the uniformity of photon density distributed along the cavity length is improved, the longitudinal space hole burning effect is restrained, and narrower line width is achieved while single longitudinal mode output is kept; the distributed feedback laser is simple in structural technological process, low in requirement for mask and etching precision and suitable for narrow-linewidth light sources with different cavity lengths and end face reflection conditions.

A distributed feedback laser (DFB) is a type of laser diode in which the active region of the device contains a periodically structured element or diffraction grating, which may include periodic changes in refractive index that cause reflection back into the laser cavity. Conventional DFB lasers used in optical networks may exploit either loss-modulated or index-modulated gratings. In the case of complex-coupling, index-modulated and loss-modulated gratings may be combined together.

The invention relates to the technical field of atom magnetometer detection and quantum sensing, and discloses a helium atom metastable state excitation density detection method, which comprises the following steps: constructing a detection system comprising a distributed feedback laser, a helium atom gas chamber, an excitation circuit and an oscilloscope; respectively acquiring an unexcited state transmission light signal, an excited state transmission light signal and a background signal by using an oscilloscope; spontaneous radiation interference is eliminated through background subtraction, laser power fluctuation is eliminated through normalization, and the helium atom metastable state excitation density is obtained through inversion according to the Lambert-Beer law. According to the invention, the helium atom metastable state excitation density inverted in real time is used as a feedback basis, and the density change is monitored to lock the optimal resonance point and impedance matching parameters of the excitation circuit. According to the invention, the influence of plasma discharge interference and laser power fluctuation is effectively eliminated, the measurement signal-to-noise ratio and accuracy are improved, and the preparation efficiency of metastable helium atoms is maximized.

The embodiment of the invention provides a high-speed modulation distributed feedback laser chip and a preparation method thereof, and the preparation method comprises the steps: carrying out first material reduction processing in a preset region of a contact surface of an initial wafer to form a first ridge waveguide, and obtaining a first wafer; arranging a first metal piece on the contact surface of the first ridge waveguide to obtain a second wafer; performing second material reduction processing on the first ridge waveguide to form a second ridge waveguide, and obtaining a third wafer; a second metal piece is arranged on one side, deviating from the second ridge waveguide, of the first metal piece. According to the manufactured chip, only metal exists in the horizontal plane where the ridge waveguide is located, no metal exists in the channel and the side wall of the ridge waveguide, meanwhile, the BCB is used as the insulating layer of the chip, the parasitic capacitance of the chip can be effectively reduced, and the bandwidth of the chip is increased.

This invention provides a method for fabricating an antimonide distributed feedback laser, comprising the following steps: S1, forming an N-type first InAs buffer layer on a substrate; S2, forming an N-type lower InAsSb confinement layer on the N-type first InAs buffer layer; S3, forming an N-type lower InAlAsSb waveguide layer on the N-type lower InAsSb confinement layer; S4, forming an InGaAs / InAlGaAsSb quantum well layer on the N-type lower InAlAsSb waveguide layer; S5, forming... S6. Forming a P-type InAlAsSb waveguide layer on the P-type InAlAsSb waveguide layer; S7. Forming a P-type second InAs buffer layer on the P-type InAsSb confinement layer; S8. Forming a P-type etch barrier layer on the P-type second InAs buffer layer; S9. Forming a P-type grating layer on the P-type etch barrier layer; S10. Forming a P-type barrier layer on the P-type grating layer; S11. Forming a P-type ohmic contact layer on the P-type barrier layer; wherein steps S1-S11 are performed using the MOCVD method. This invention also provides an antimonide distributed feedback laser fabricated using this method.