125 results about "External cavity laser" patented technology

The invention discloses a spot-size converter (SSC) and a high-power external cavity laser chip, the external cavity laser chip comprises a wide-ridge gain chip and a passive external cavity chip, one end of the wide-ridge gain chip is plated with a high-reflection film as a reflection end, and the other end of the wide-ridge gain chip is plated with an antireflection film to realize low reflection; and efficient coupling of the fundamental mode of the wide-ridge gain chip with the size far larger than that of the single-transverse-mode waveguide and the small-size single-mode waveguide is realized by integrating the SSC. The SSC converts a large-size mode field and a small-size mode field mutually and effectively reduces optical coupling loss, mode selection and output wavelength adjustability are achieved by adjusting the longitudinal mode phase shifter and the micro-ring filter, part of power is fed back to the wide-ridge gain chip to construct external cavity resonance, and high-power output is achieved. According to the SSC, the device size can be remarkably reduced, a wide-ridge gain chip and an inter-chip hybrid integration process are compatible, and the tuning flexibility, the integration level and the overall stability of the laser are further improved while high-power output is kept.

The invention discloses an independent double-single-side-band direct detection system based on geometric shaping and digital chaotic encryption, and belongs to the field of terahertz communication. According to the detection system, an external cavity laser ECL of a sending end generates continuous optical carriers, the continuous optical carriers are input into an I / Q modulator, a TX-DSP module generates two independent vector radio frequency signals of GS-QPSK and GS-NQAM through geometric shaping and a three-dimensional multi-vortex chaos system technology, the I / Q modulator is driven to modulate the input optical carriers, and the optical carriers are transmitted to a receiver. After being amplified, the terahertz signals are input into a one-way carrier photoelectric detector for frequency beating to obtain independent double-sideband terahertz signals, the independent double-sideband terahertz signals are input into a frequency mixer of a receiving end for frequency mixing with generated local oscillation signals, down-conversion of the signals is achieved, and fundamental frequency signals are obtained; and then the data are input to an RX-DSP module, normalization, down-sampling, signal separation, de-mapping, symbol-level and bit-level decryption and other operations are carried out, and finally two paths of original data are obtained to solve the bit error rate. According to the invention, the system communication capacity is improved, and the security of independent double-sideband signal transmission is improved.

The invention relates to the technical field of semiconductor lasers, in particular to an ultra-narrow linewidth wavelength-adjustable external cavity laser based on a planar metal grating, which comprises a gain chip, and the left end face and the right end face of the gain chip are respectively plated with a high reflection film and a first antireflection film; a planar metal grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip is aligned and attached to the left end face of the planar metal grating waveguide, and a second antireflection film and a third antireflection film are plated on the left end face and the right end face of the planar metal grating waveguide respectively; the planar metal grating waveguide comprises a grating waveguide substrate, a ridge optical waveguide is arranged on the upper portion of the grating waveguide substrate, an annular resonance optical waveguide is arranged on the front side of the ridge optical waveguide, a planar metal grating is arranged on the upper portion of the ridge optical waveguide, and a top covering layer is arranged on the upper portion of the planar metal grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 700Hz and M2 less than 0.9 is realized.

An improved external cavity laser (1) is provided herein that comprises a gain section (2) and an external cavity passive chip (3) with a first end (31) that is optically coupled to the gain section (2) and with a second end (35) providing a laser output, the external cavity passive chip (3) having a cavity (33) between the first end (31) and a phase shifted Bragg grating, FBG (34).

The invention relates to the technical field of semiconductor lasers, in particular to an external cavity laser for realizing narrow linewidth through phase difference regulation and control of a bimetallic Bragg grating, which comprises a gain chip, a first high-reflection (HR) film is plated on the left end surface of the gain chip, and a first anti-reflection (AR) film is plated on the right end surface of the gain chip; a metal Bragg grating waveguide is arranged on the right side of the gain chip, an annular resonance optical waveguide is arranged on the front side of the ridge optical waveguide, the right end face of the gain chip and the left end face of the metal Bragg grating waveguide are aligned and attached to form an outer cavity structure, and the left end face of the metal Bragg grating waveguide is plated with a second anti-reflection AR film. The right end face of the metal Bragg grating waveguide is plated with a third anti-reflection AR film. Tests show that the side mode rejection ratio (SMSR) is increased to 65dB and the line width is compressed to 0.6 kHz by using an interference enhancement effect and a mode suppression mechanism.

There is provided an external cavity laser, including: a photonic integrated platform including a gain chip providing a gain medium and at least one reflector chip, the photonic integrated platform including first and second functional layers made of different materials; a resonant cavity optically coupled to the gain medium and including a first and a second micro-ring resonators (MRR) in a Vernier configuration, the first MRR and second MRR extending within respective ones of the first and second functional layers made of different materials and having corresponding group indices, the first and second MRRs having different radii selected in view of said corresponding group indices; and a tuning mechanism for tuning a spectral response of at least one of the first and second MRR.

The invention relates to an optical radiation source. It is an object of the invention to enable the generation of laser radiation with (ultra) narrow linewidth and to provide an optical radiation source which is robust and simple to control. The optical radiation source of the invention comprises: a laser source having a gain medium and an internal cavity configured to generate laser radiation at multiple frequencies separated by a first free spectral range, at least one external cavity in optical communication with the laser source, the external cavity having a plurality of resonance modes within the gain bandwidth of the laser source, wherein the resonance modes are separated by a second free spectral range which is different from the first free spectral range, wherein the external cavity is configured to act as a frequency-selective reflector to selectively reflect laser radiation generated by the laser source back into the gain medium, thereby causing the gain medium to lase predominantly at only one frequency, and wherein the optical radiation source is configured to couple a portion of the generated laser radiation out from the internal cavity and / or from the external cavity.

A high-speed switching N-bit path selection type silicon-based integrated microwave photon delay line comprises a wavelength tunable external cavity laser, an electro-optical modulator, an N-bit wavelength selection delay line and a photoelectric detector, and the wavelength selection delay line is composed of N + 1 2 * 2 wavelength interleavers and N groups of delay and reference waveguide pairs. After being modulated by a microwave signal, light output by the external cavity laser is input into the N-bit wavelength selection delay line and finally converted into a microwave signal through the photoelectric detector to be output. By switching the wavelength of the laser, high-speed switching of a delay light path can be realized, and then high-speed phase shifting of a microwave signal is realized. According to the scheme, the wavelength selection type delay line adopts a passive device design, and compared with a traditional optical switch type delay line, the wavelength selection type delay line is easy to realize low loss, does not need voltage regulation and control, and is low in overall system power consumption.

The invention belongs to the field of lasers, and particularly discloses an external cavity laser and equipment, the external cavity laser comprises a gain chip, an external resonant cavity and a coupling module, the gain chip and the external resonant cavity are coupled through the coupling module, the external resonant cavity comprises a waveguide structure, an optical grating and a phase change material layer, and the optical grating is arranged on the waveguide structure. The grating is arranged on the waveguide structure, the phase change material layer is arranged on the surface of the grating in a stacked mode and comprises a plane portion and a protruding portion which are connected with each other, and the protruding portion is filled in a groove of the grating. Therefore, the external cavity laser can reduce the energy consumption while realizing the rapid tuning of the wavelength.

The invention relates to the technical field of semiconductor lasers, in particular to a compact ultra-narrow linewidth external cavity laser based on a top metal reflection grating, which comprises a gain chip, the left end face of the gain chip is plated with a high reflection film, and the right end face of the gain chip is plated with a first antireflection film; the right side of the gain chip is provided with a metal grating waveguide, the right end face of the gain chip is aligned and attached to the left end face of the metal grating waveguide, the left end face of the metal grating waveguide is plated with a second antireflection film, and the right end face of the metal grating waveguide is plated with a third antireflection film; the gain chip comprises a substrate, the upper part of the substrate is provided with a ridge optical waveguide, and the upper part of the ridge optical waveguide is provided with a metal cover Bragg reflection grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 750Hz and M2 less than 1.1 is realized.

The invention relates to the technical field of semiconductor lasers, in particular to an ultra-narrow linewidth wavelength-adjustable external cavity laser based on a planar metal grating, which comprises a gain chip, and the left end face and the right end face of the gain chip are respectively plated with a high reflection film and a first antireflection film; a planar metal grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip is aligned and attached to the left end face of the planar metal grating waveguide, and a second antireflection film and a third antireflection film are plated on the left end face and the right end face of the planar metal grating waveguide respectively; the planar metal grating waveguide comprises a grating waveguide substrate, a ridge optical waveguide is arranged on the upper portion of the grating waveguide substrate, a planar metal grating is arranged on the upper portion of the ridge optical waveguide, and a top covering layer is arranged on the upper portion of the planar metal grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 700Hz and M2 less than 0.9 is realized.

The utility model discloses a silicon-based large-range tunable external cavity laser, which comprises two reflection-type semiconductor optical amplifiers with adjacent gain bands, and the two reflection-type semiconductor optical amplifiers are respectively connected to two input ends of an optical switch through a silicon-based light spot size converter. One output end of the optical switch is connected with the input end of the first micro-ring filter through the phase shifter, the output end of the first micro-ring filter is connected with the input end of the second micro-ring filter, and the output end of the second micro-ring filter is connected with the input end of the adjustable Sagnac reflector. And the output port of the Sagnac reflector is a laser emitting port. According to the utility model, the reflection type semiconductor optical amplifiers of two adjacent gain wave bands are integrated at the two input ends of the optical switch, so that the gain puffing range of the laser is greatly enlarged, the wavelength range of the laser is expanded, and the loop loss is effectively reduced by utilizing the thermo-optic effect of a silicon substrate.

There is provided an external cavity laser, including: a photonic integrated platform including a gain chip providing a gain medium and at least one reflector chip, the photonic integrated platform including first and second functional layers made of different materials; a resonant cavity optically coupled to the gain medium and including a first and a second micro-ring resonators (MRR) in a Vernier configuration, the first MRR and second MRR extending within respective ones of the first and second functional layers made of different materials and having corresponding group indices, the first and second MRRs having different radii selected in view of said corresponding group indices; and a tuning mechanism for tuning a spectral response of at least one of the first and second MRR.

The application discloses a kind of photonic-assisted terahertz signal transmission system and method, including the terahertz signal photon generation module, transmission module and photoelectric conversion module connected in turn;The terahertz signal photon generation module is used to generate the optical signal containing terahertz signal;The transmission module is used to transmit the optical signal containing terahertz signal at different distances, and send it into photoelectric conversion module;The photoelectric conversion module is used to convert the received optical signal containing terahertz signal into terahertz signal.Setting a laser realizes multiple multi-band signal generation, avoids using external cavity laser to reduce the phase noise of generated signal, in addition, long-distance transmission is carried out using optical fiber, solve the technical problem that prior art cannot realize long-distance communication.

The invention relates to the technical field of semiconductor lasers, in particular to an external cavity laser for realizing narrow linewidth through phase difference regulation and control of a bimetallic Bragg grating, which comprises a gain chip, a first high-reflection (HR) film is plated on the left end surface of the gain chip, and a first anti-reflection (AR) film is plated on the right end surface of the gain chip; a metal Bragg grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip and the left end face of the metal Bragg grating waveguide are aligned and attached to form an outer cavity structure, and the left end face of the metal Bragg grating waveguide is plated with a second anti-reflection AR film. The right end face of the metal Bragg grating waveguide is plated with a third anti-reflection AR film. Tests show that the side mode rejection ratio (SMSR) is increased to 65dB and the line width is compressed to 0.6 kHz by using an interference enhancement effect and a mode suppression mechanism.

This invention relates to a high-power narrow-linewidth laser with weak feedback in an external cavity, comprising: a sub-source output section for outputting a sub-source; a laser output section for outputting narrow-linewidth laser light; an isolator disposed between the sub-source output section and the laser output section; a multilayer reflective film assembly deposited on the input end of the isolator or on the output end of the sub-source output section for filtering the sub-source to form transmitted light and feedback light; the rear end of the isolator outputs the transmitted light to the laser output section as narrow-linewidth laser output; the sub-source output section also receives the feedback light to achieve self-injection locking, possessing the advantages of high-power narrow-linewidth laser output, simple structure, low cost, simple process, relatively small packaging size, and ease of laser packaging.

An improved external cavity laser (1) is provided herein that comprises a gain section (2) and an external cavity passive chip (3) with a first end (31) that is optically coupled to the gain section (2) and with a second end (35) providing a laser output, the external cavity passive chip (3) having a cavity (33) between the first end (31) and a phase shifted Bragg grating, FBG (34).

The invention provides a tunable external cavity laser chip and a preparation method thereof, and relates to the technical field of lasers, the chip comprises a planar optical waveguide loop and a gain chip; a narrow-band transmission peak of a micro-ring resonator and an interference passband of a multi-channel interference module are preliminarily aligned through a phase shifter array and a first micro-ring phase shifter in a planar optical waveguide loop, and selection of a lasing working point is completed; and the common phase shifter and the second micro-ring phase shifter are used for cooperative driving, laser frequency sweeping is carried out on the basis of preliminary alignment, and accurate alignment of a narrow-band transmission peak and an external cavity longitudinal mode is maintained in the whole frequency sweeping process. Through cooperative driving of the common phase shifter and the micro-ring phase shifter, the sweep frequency bandwidth of the laser is increased, and frequent mode hopping of output laser in the tuning process is avoided; meanwhile, the periodic alignment reflection phenomenon in a reflection spectrum is avoided, the utilization rate of the gain interval of the semiconductor gain chip is greatly improved, and a larger tuning range is obtained under the condition that the quality of light beams is kept unchanged.

The application provides a device and a method for realizing PON rate adjustment based on Polar modulation, and relates to the technical field of passive optical networks.The device comprises a first external cavity laser, a second external cavity laser, a dual-polarization phase quadrature modulator, an arbitrary waveform generator, an erbium-doped fiber amplifier, a single-mode optical fiber, a variable optical attenuator, a coherent receiver and an oscilloscope.The method comprises the following steps: dynamically adjusting the number of information bits A, splicing check bits to form total information bits, optimizing the distribution of information bits and frozen bits according to the optical signal channel sorting result, performing polar encoding on the signal at the encoding end, and mapping the signal into a 16QAM code symbol sequence by using the Polar modulation technology; at the receiving end, calculating the LLR, calculating the path metric value of all paths and performing a pruning operation when the list width reaches a set value, and detecting the L candidate paths by using the CRC check after the decoding is completed.The application realizes flexible regulation and control of the transmission rate of different optical network units.

The invention relates to the technical field of semiconductor lasers, in particular to a compact ultra-narrow linewidth external cavity laser based on a top metal reflection grating, which comprises a gain chip, the left end face of the gain chip is plated with a high reflection film, and the right end face of the gain chip is plated with a first antireflection film; the right side of the gain chip is provided with a metal grating waveguide, the right end face of the gain chip is aligned and attached to the left end face of the metal grating waveguide, the left end face of the metal grating waveguide is plated with a second antireflection film, and the right end face of the metal grating waveguide is plated with a third antireflection film; the gain chip comprises a substrate, the upper part of the substrate is provided with a ridge optical waveguide, and the upper part of the ridge optical waveguide is provided with a metal cover Bragg reflection grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 750Hz and M2 less than 1.1 is realized.

This invention belongs to the field of communication technology, specifically a millimeter-wave communication and sensing integrated transmission system based on LFM-OFDM signals. The system comprises a transmitter and a receiver. The transmitter mainly includes an input module, an optical modulator, a light source, and a photodetector. The input module generates the information to be modulated; the optical modulator modulates the information to be transmitted onto the sidebands of the optical carrier; an external cavity laser serves as the light source; and the photodetector performs photoelectric conversion. The receiver mainly includes an antenna, a demodulator, and an output module. The antenna receives the millimeter-wave signal and outputs it to the demodulator for demodulation at both the communication and sensing ends; the output module outputs the demodulated information. This system not only enables millimeter-wave band communication and sensing devices but also generates broadband LFM signals, achieving high-resolution sensing and high-speed communication.

The invention discloses a modulation grating Y-branch broadband tuning external cavity laser and equipment. The modulation grating Y-branch broadband tuning external cavity laser comprises a semiconductor optical amplifier (SOA) gain chip area; an outer cavity waveguide region; the semiconductor optical amplifier SOA gain chip area and the outer cavity waveguide area are in coupling connection through the coupling module, and the outer cavity waveguide area comprises a waveguide structure; the Y-branch sampling grating structure is arranged on the surface of the waveguide structure, the Y-branch sampling grating structure is provided with a first sampling grating and a second sampling grating, a chalcogenide phase change material layer is arranged on the surface of the first sampling grating or the second sampling grating, and the chalcogenide phase change material layer comprises a plane part and a convex part which are connected with each other; and the convex part is filled in the groove of the first sampling grating or the second sampling grating. Therefore, rapid and accurate multi-stage wavelength tuning of the external cavity laser can be realized in an extremely short time, and meanwhile, the power consumption of the external cavity laser is effectively reduced.

The invention provides an oil and gas pipeline hydrate generation monitoring system and method based on a phi-OTDR, and belongs to the technical field of pipeline natural gas monitoring. Comprising an external cavity laser, a coupler, an acousto-optic modulator, a first erbium-doped amplifier, a circulator, a to-be-detected optical fiber, a to-be-detected pipeline, a second erbium-doped amplifier, an attenuator, a frequency mixer, an optical detector, a low-pass filter, a data acquisition card and an upper computer. The external cavity laser is connected with the coupler, the coupler is connected with the acousto-optic modulator, the acousto-optic modulator is connected with the first bait-doped amplifier, the first bait-doped amplifier is connected with the circulator, the optical fiber to be measured is tightly laid on the outer wall of a pipeline to be measured, a port of the circulator is connected with the end of the optical fiber to be measured, and the circulator is connected with the second bait-doped amplifier. The second erbium-doped amplifier is connected with the attenuator, the attenuator is connected with the frequency mixer, the frequency mixer is connected with the coupler and the optical detector, the optical detector is connected with the low-pass filter, the low-pass filter is connected with the data acquisition card, and the data acquisition card is connected with the upper computer.

A tunable light source for a frequency-modulated continuous wave (FMCW) LiDAR device includes an external cavity laser including a laser gain medium having a light output facet emitting laser light, a reflector and an external cavity waveguide extending between the light output facet and the reflector. A variable phase shifter is arranged in the external cavity waveguide. An optical splitter splits off a portion of the laser light and has an output port. An optical phase-locked loop is optically coupled to the optical splitter and electrically coupled to the laser gain medium. The optical phase-locked loop includes a first arm and a second arm, a double stage single-sideband Weaver mixer including an optical stage and an electrical stage, a phase detector and a loop filter that are electrically connected in series. The first arm and the second arm have different optical path lengths.

To provide an external resonant laser module capable of improving yield, and a method of manufacturing the same.SOLUTION: A laser module 1 includes a QCL element 2, a diffraction grating unit 5, lens holders 7A and 7B, and a mount member 4. A fourth mounting portion 44 of the mount member 4 is provided with a placement hole 44b into which a protruding portion 53c of the diffraction grating unit 5 is inserted. The placement hole 44b is longer than the protruding portion 53c so that the protruding portion 53c can be slid in an X-axis direction relative to the placement hole 44b. A wall surface 43c for positioning the diffraction grating unit 5 is provided between a third mounting portion 43 and the fourth mounting portion 44. The diffraction grating unit 5 has a positioning surface 53d facing the wall surface 43c. The diffraction grating unit 5 is fixed to the fourth mounting portion 44 in a state where the protruding portion 53c is inserted into the placement hole 44b and the positioning surface 53d is in surface contact with the wall surface 43c.SELECTED DRAWING: Figure 8

The present invention discloses an independent dual-single-sideband direct detection system based on geometric shaping and digital chaos encryption, which belongs to the field of terahertz communication. In the detection system, the external cavity laser ECL at the transmitting end generates a continuous optical carrier, which is input to the I / Q modulator. The TX-DSP module uses geometric shaping and three-dimensional multi-vortex chaotic system technology to generate two independent vector radio frequency signals of GS-QPSK and GS-NQAM, drives the I / Q modulator to modulate the input optical carrier, and after amplification, inputs it to a single-row carrier photodetector for beat frequency to obtain an independent double-sideband terahertz signal, which is input to the mixer at the receiving end for mixing with the generated local oscillator signal to achieve signal down-conversion and obtain a baseband signal; then it is input to the RX-DSP module for normalization, down-sampling, signal separation, demapping, symbol-level and bit-level decryption, and finally obtains two channels of original data to calculate the bit error rate. The present invention improves the communication capacity of the system and improves the security of independent double-sideband signal transmission.

Disclosed is a refractive index sensor that includes a reference laser and a RI sensitive laser wherein the reference and RI sensitive lasers have reference and sensing oscillating frequencies respectively. The reference laser is configured to maintain the oscillating frequency at a constant value, upon exposure of the refractive index senor to an input sample, and the RI sensitive laser has the sensing oscillating frequency that varies based on a refractive index of the input sample, upon exposure to the input sample. The reference laser and RI sensitive lasers generate reference and sensing signals, and a photodiode receives and combines the reference and sensing signals to generate a combined signal that has a beat frequency proportional to the refractive index of the input sample. A computing unit determines the refractive index of the input sample based on the beat frequency.

The application relates to the technical field of semiconductor lasers, in particular to a high-performance intracavity laser based on a micro-gain grating region double-side AR plus an inclined angle, which comprises a high-performance intracavity laser based on a micro-gain grating region double-side AR plus an inclined angle, including a substrate layer and a back ridge waveguide; the back ridge waveguide is arranged on the upper end face of the substrate layer; the back ridge waveguide comprises a composite structure grating section located on the left side and a gain region waveguide section located on the right side; an i-layer semiconductor Bragg grating is etched in the composite structure grating section, and i is a natural number; a metal grating electrode is covered on the top of the composite structure grating section; a quantum well layer is arranged in the gain region waveguide section; a gain region electrode is covered on the top of the gain region waveguide section; and an inclined end face is arranged at the left end of the gain region waveguide section. The application overcomes the inherent defects of traditional DBR, DFB and traditional external cavity lasers from the aspects of structure and mechanism.

The invention relates to the technical field of semiconductor lasers, in particular to a high-speed wavelength-adjustable narrow-linewidth external cavity laser which comprises an InP gain chip optical waveguide, the left end face of the InP gain chip optical waveguide is plated with an optical high-reflection film, and the right end face of the InP gain chip optical waveguide is plated with a first optical antireflection film; the left end face of the lithium niobate waveguide is plated with a second optical antireflection film, and the right end face of the lithium niobate waveguide is plated with a third optical antireflection film; a lithium niobate film Bragg grating waveguide is arranged on the upper end face of the lithium niobate waveguide, a SiO2 layer is arranged below the lithium niobate film Bragg grating waveguide, and a Si substrate is arranged below the SiO2 layer; the right end face of the InP gain chip optical waveguide is aligned and attached to the left end face of the lithium niobate waveguide to form an outer cavity structure; a voltage control unit is further arranged on the upper end face of the lithium niobate waveguide. Through the 1-3cm ultra-long grating and mode matching optimization, the advantages of 0.8 kHz line width, 50nm tuning range, light beam quality with M less than 1.2 and device response speed mu s level are realized.

The present invention discloses a gas Raman detection device based on a semiconductor laser self-locked enhancement cavity, belonging to the field of gas detection. The device comprises a laser unit, a laser linewidth narrowing unit, a self-locked enhancement cavity unit, and a Raman scattered light collection unit. A mode-matching lens is used to tilt the laser beam emitted by the semiconductor laser into an enhanced external cavity. The laser beam is then repeatedly reflected within a confocal spherical mirror cavity formed by a first spherical reflector M1 and a second spherical reflector M2. Part of the laser light is emitted from the external cavity and returns to the semiconductor laser, forming optical feedback, causing the semiconductor laser and the enhanced external cavity to resonate in frequency. The device eliminates the need for enhanced cavity length feedback, resulting in a simple and stable optical path layout, which can simultaneously reduce optical path complexity and device cost. The device boasts an external cavity laser power of tens of watts, and the laser linewidth narrowed by the laser linewidth narrowing unit enables the Raman signal spectrum to have higher resolution and intensity.