82 results about "Distributed feedback laser" patented technology

The invention discloses a distributed feedback laser and a preparation method thereof, and relates to the field of lasers. The preparation method of the distributed feedback laser comprises the following steps: forming a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an upper limiting layer, a grating layer, a grating buried layer, a corrosion stop layer, an InP cladding, a barrier gradient layer, a contact layer and a sacrificial layer on a substrate, wherein the sacrificial layer comprises an InP layer and an InGaAs layer which are stacked in sequence; etching to form a ridge waveguide structure; forming an insulating layer; removing the insulating layer in a preset area on the ridge waveguide structure to expose the sacrificial layer; wherein the side wall of the InGaAs layer is completely exposed, and the side wall of the InP layer is partially exposed; and etching to remove the InGaAs layer and the InP layer to form an upper electrode layer and a lower electrode layer. According to the invention, the reliability and the electro-optical conversion efficiency of the distributed feedback laser can be improved.

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.

An optical transmitter includes a distributed feedback (DFB) laser having an active region formed as a multiple quantum well (MQW) and a diffraction grating, an electro-absorption (EA) modulator having an absorption region formed as a MQW having a composition different from a composition of the DFB laser, a semiconductor amplifier (SOA) having an active region having a same composition as the composition of the DFB laser, a bent waveguide that rotates a light propagation direction, and a passive waveguide connected to the SOA and including a core having a band gap wavelength shorter than an oscillation wavelength of the DFB laser. A tapered region of the passive waveguide converts a width W1 of the passive waveguide connected to the SOA into a width W2 of a narrow waveguide region of the passive waveguide, and the passive waveguide is in contact with the end surface of the substrate.

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 invention discloses a direct modulation distributed feedback semiconductor laser and a preparation method thereof. An epitaxial layer structure of the direct modulation distributed feedback semiconductor laser sequentially comprises a substrate, a buffer layer, a first limiting layer, an active layer, a second limiting layer, an upper cladding and a top contact layer from bottom to top, the epitaxial layer structure also comprises a variable period grating layer which changes periodically along the cavity length direction. The period of the variable-period grating layer corresponds to refractive index distribution in a laser cavity, the grating period corresponding to a region with a relatively large refractive index is relatively small, and the grating period corresponding to a region with a relatively small refractive index is relatively large; and the variable-period grating layer can realize chirp control of the output signal. The chirp effect formed by the material when the device is modulated is reduced or compensated through the chirp effect of the variable-period grating layer structure, so that the limitation of parasitic chirp of the device on the transmission performance is solved.

The present disclosure relates to a monolithically integrated dual-wavelength transmitter for a passive optical network (PON), which may be suitable for both a gigabit PON (GPON) and a 10-gigabit-PON (XG-PON). The integrated transmitter includes two distributed feedback (DFB) lasers, a first DFB laser to emit a continuous first laser beam at a first wavelength along an optical path, and a second DFB laser to emit a modulated second laser beam at a second wavelength along the optical path in the same direction as the first DFB laser. The transmitter also includes an electro-absorption modulator (EAM) after the first DFB laser in the optical path, which is configured to modulate the first laser beam, and a distributed Bragg reflector (DBR) between the EAM and the second DFB laser in the optical path, which is configured to transmit light at the first wavelength

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.

The invention discloses a distributed feedback laser array line width narrowing device and method based on self-injection feedback, and the device is characterized in that a laser array is connected with an array waveguide grating, the array waveguide grating is connected with an optical fiber circulator, and the optical fiber circulator is connected with an optical fiber coupler; the output of the laser array is combined through the array waveguide grating and then input into the optical fiber circulator, part of laser entering the optical fiber coupler from the optical fiber circulator passes through the optical fiber circulator and the array waveguide grating again and is injected into the laser array in the form of optical feedback, and the working state of the laser array is influenced by the optical feedback. And the line width of the laser array is narrowed. Through the synergistic effect of the laser array, the array waveguide grating, the optical fiber circulator and the optical fiber coupler, a self-injection feedback loop is constructed, part of output laser is re-injected into the laser unit after wave combination and light splitting, and phase noise is suppressed through optical feedback, so that the linewidth is remarkably reduced.

According to a first aspect, the present disclosure relates to a distributed feedback (DFB) laser configured to control a wavelength of emitted light from the DFB laser, the DFB laser comprising a planar substrate, a substantially planar front facet with an anti-reflective coating, the front facet substantially perpendicular to the planar substrate, a substantially planar rear facet with a high reflectivity coating, the rear facet substantially perpendicular to the planar substrate, a laser section positioned between the rear facet and the front facet, the laser section comprising: a first ensemble of substantially planar layers configured to produce, with said planar substrate, a first PIN junction, the first ensemble of substantially planar layers comprising: a first top layer substantially parallel to the planar substrate; an active layer substantially parallel to the planar substrate and configured to emit light through the front facet, the active layer arranged between the planar substrate and the first top layer; a grating layer arranged substantially parallel to the active layer, the grating layer arranged between the planar substrate and the first top layer in proximity to the active layer; a Bragg grating arranged in said grating layer and configured to reflect light towards said front facet; and a phase section positioned between the rear facet and the laser section, the phase section comprising: a second ensemble of substantially planar layers comprising: a second top layer substantially parallel to the planar substrate, the second top layer substantially coplanar with the first top layer; an optical layer arranged between the planar substrate and the second top layer, the optical layer substantially coplanar with the active layer and optically coupled with the active layer; a non-grating layer substantially coplanar with the grating layer; and an element in electrical or thermal contact with the optical layer, the element configured, under application of a current or voltage, to change a refractive index of the optical layer so as to change the wavelength of the emitted light.

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.

Degenerate distributed feedback lasers utilizing DBE-supporting waveguides are provided. In one embodiments, a degenerate distributed feedback laser (DDFB) is provided, the DDFB laser comprising: a pump source operatively connected to a gain system, wherein the pump source provides power to a gain system; the gain system operatively connected to at least one DBE-supporting waveguide, wherein the gain system stimulates emission and amplification for lasing; at least one DBE-supporting waveguide that supports four degenerate modes and a degenerated feedback; and a coupler operatively connected to the at least one DBE-supporting waveguide, wherein the coupler collects and focuses light from the DBE-supporting waveguide and outputs a laser beam.

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 invention discloses a device and method for detecting hydrogen in transformer oil, and the device comprises a capillary tube which is filled with a heat conduction material; the distributed feedback laser is arranged in the capillary tube and partially extends out of the two ends of the capillary tube; the palladium film is deposited on the outer wall of the capillary tube, and the palladium film absorbs hydrogen and releases heat, so that the wavelength of the distributed feedback laser is changed to obtain the hydrogen concentration. According to the application, high precision, high sensitivity, high selectivity and long-term stability of hydrogen detection in transformer oil are realized through collaborative innovation of a capillary tube closed structure, a high-efficiency heat conduction material, a distributed feedback laser, wavelength detection and a palladium membrane selective absorption technology; the influence of the external environment on internal components is effectively isolated, and the stability of the sensor under complex working conditions is remarkably improved. In addition, the heat conduction material ensures that heat is uniformly distributed in the sensor, measurement errors caused by local overheating are avoided, and the service life of equipment is prolonged.

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.

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 discloses a distributed feedback laser and a method for fabricating the same. The laser comprises: a laser epitaxial structure comprising a substrate and a multilayer epitaxial layer located on one side of the substrate; a first electrode layer located on a side of the epitaxial layer away from the substrate; wherein the multilayer epitaxial layer comprises at least one grating resonant cavity structure, the grating resonant cavity structure comprising a first grating structure, a resonant cavity structure, and a second grating structure sequentially arranged along a first direction; the grating period of the first grating structure and the second grating structure is different from the grating period of the resonant cavity structure, and the first grating structure, the resonant cavity structure, and the second grating structure have only one common lasing mode; and a second electrode layer located on a side of the substrate away from the epitaxial layer. The present invention effectively reduces the number of gratings prepared, lowers the grating preparation precision requirements, reduces the difficulty and cost of device preparation, and simultaneously reduces the optical loss of the device, improves the optical coupling efficiency, suppresses multimode lasing, and significantly improves the application performance of the device.

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.