103 results about "Distributed feedback laser" patented technology

Electro-absorption modulators (EAM) and monolithically integrated electro-absorption modulated lasers (EML) and methods of fabrication are disclosed. Vertically stacked waveguides for a distributed feedback (DFB) laser, an electro-absorption modulator (EAM) and a passive output waveguide are vertically integrated, and the DFB laser, EAM and output waveguide are optically coupled using laterally tapered vertical optical couplers. Laterally tapered vertical optical couplers provides an alternative to conventional butt-coupling of a laser and EAM, offering improved reliability for high power operation over extended lifetimes. Optionally, the EML comprises monolithically integrated electronic circuitry, e.g., driver and control electronics for the DFB laser and EAM. Beneficially, integrated EAM driver and control circuitry comprises a high-speed electro-optical control loop for very high-speed linearization and temperature compensation, e.g. to enable advanced modulation schemes, such as PAM-4 and DP-QPSK, for analog optical data center interconnect applications. Some embodiments are compatible with fabrication using a single epitaxial growth.

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 discloses a compact monolithic dual-wavelength distributed feedback laser device and a manufacturing method thereof, and belongs to the technical field of laser, the laser device is composed of a front part, a middle part and a rear part, and the middle part comprises two equivalent Pi phase shift chirp sampling gratings. The laser is based on a reconstruction equivalent chirp technology and has a tunable wavelength interval. A chirp sampling grating with two equivalent phase shifts is arranged in the laser, and the grating is composed of a front part, a middle part and a rear part. Phase matching is achieved through the microstructure quasi-phase matching technology, it is ensured that a laser resonant cavity reaches the phase matching condition at the phase shift position, and wide-range adjustment expanded from 59.50 GHz to 116.25 GHz can be effectively achieved by changing injection current. The invention has the advantages of accurate wavelength control, simple structure, low power consumption, high integration level and the like.

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.

Provided is an optical transmitter having high manufacturing stability and a high reflection suppression effect. In the optical transmitter, a distributed feedback (DFB) laser having an active region formed as a multiple quantum well that generates an optical gain by current injection and a diffraction grating, an electro-absorption (EA) modulator having an absorption region formed as a multiple quantum well 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 by an angle θwg, 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 are monolithically integrated on one substrate. The passive waveguide has a tapered region and a narrow waveguide region. The tapered region converts a width W1 of the passive waveguide connected to the SOA into a width W2 of the narrow waveguide region, and the passive waveguide forms the angle θwg with respect to a normal line to an end surface of the substrate and is in contact with the end surface of the substrate.

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 relates to an in-situ detection device and method for gas dissolved in oil. Comprising a degassing module and a detection module, and the degassing module is in direct contact with transformer oil and used for separating dissolved gas in the transformer oil in a membrane degassing mode to obtain separated gas; the detection module comprises a distributed feedback laser, a coupler, a photoacoustic cell, a plurality of photoelectric detectors, an AD conversion module and an FPGA core control and demodulation system; the method comprises the following steps: introducing separated gas, exciting the separated gas in a photoacoustic cell by multiple beams of laser to generate a photoacoustic or optical signal, receiving the signal, demodulating the signal after AD conversion to obtain Raman scattering spectrum data, and analyzing the Raman scattering spectrum data to obtain the concentration of each component gas in the separated gas. And judging the internal fault type of the transformer according to the concentration of each component gas. The device can be in direct contact with transformer oil for gas separation detection, and interference possibly brought by a traditional detection method in the oil sample extraction and analysis process is avoided.

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.

A modified distributed feedback (DFB) laser comprises a gain region with a distributed feedback grating and a back reflector that receives a portion of laser light generated by the gain region and the distributed feedback. The back reflector is a wavelength-selective reflector that retroreflects the portion of the received laser light back to the gain region, thereby stimulating single mode laser oscillation and / or improving a side mode suppression ratio (SMSR) of the laser light generated by the modified DFB laser. The spectral properties of the laser output by the modified DFB laser can be independent of position of a cleaved facet of the laser chip near a back end of the modified DFB laser and / or the performance of the modified DFB laser can be maintained over a large number of laser chips separated from a wafer.

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.

A four-dimensional (4D) light-detection-and-ranging sensor using frequency modulated continuous wave is provided with an ultra-high velocity resolution. At a transmitting terminal, the hybrid waveform of a driving laser is used to minimize the phase noise generated by a distributed-feedback laser during wavelength scanning. The hybrid waveform is obtained by combining direct-current signal (not modulated) and alternating-current (AC) signal. The AC signal is a predistorted triangle or AC waveform for extracting location. The continuous wave (CW) extracts velocity. At a receiving terminal, a radar radio-frequency receiver is combined with an avalanche photodiode (APD) with multiple layers accumulated in series to obtain excellent responsivity and saturated current. The mixed waveform coordinated with the APD prevents Doppler shift frequency from being contaminated by low-frequency flicker noise. Thus, a good-quality 4D image is provided; and the use of the APD improves the pixel contrast between the object and background.

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.

A chip, a chip-on-carrier, a transmitter, and a related device. The chip comprises a conductive substrate (100), an insulating layer (200), a quantum well (300), a first capacitor pad (400), a distributed feedback laser (DFB) pad (500) and an electrical absorption modulator (EAM) pad (600), wherein the insulating layer (200) and the quantum well (300) are grown on the conductive substrate (100), the DFB pad (500) and the EAM pad (600) are grown on the insulating layer (200) and the quantum well (300), the first capacitor pad (400) is grown on the insulating layer (200), and the first capacitor pad (400) is used for forming a first capacitor with the conductive substrate (100). In this way, a capacitor is built in an EML chip, such that the modulation effect of a high-frequency signal on a DFB region can be effectively mitigated while a COC structure and process are simplified, thereby realizing differential driving having a lower RIN.

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 embodiment of the invention provides a distributed feedback laser, relates to the technical field of lasers, and is used for solving the problem that the performance is affected by insertion of a phase shift grating. The laser comprises a ridge waveguide and feedback gratings arranged on the two sides of the ridge waveguide, each feedback grating comprises a Bragg grating and a phase shift grating inserted into the Bragg grating, the Bragg grating comprises two connecting gratings located on the two sides of the phase shift grating respectively, and each connecting grating comprises a chirp grating and a uniform grating which are connected. The uniform grating is away from the phase shift grating relative to the chirp grating. The length of grating teeth in the chirp grating is a first length, and the duty ratio is a first duty ratio; the width of a part, corresponding to the chirp grating, of the ridge waveguide is a first waveguide width; in the process of approaching the uniform grating from the phase shift grating along the first direction, at least one of the first length, the first duty ratio and the first waveguide width is gradually changed to realize grating coupling coefficient chirp of the chirp grating. The laser can be applied to the field of optical communication.

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.