24 results about "Directly modulated laser" patented technology

The invention relates to the technical field of photoelectronics, and discloses a chirp parameter measuring device and method based on a directly modulated laser optical module, and the device comprises an arbitrary waveform generator, an optical module, a tunable dispersion compensation module, and an oscilloscope. The optical module comprises a directly modulated laser; the output of the arbitrary waveform generator is electrically connected with the radio frequency input port of the directly modulated laser; the output optical signal end of the directly modulated laser is connected with the input optical end of the adjustable dispersion compensation module; the adjustable dispersion compensation module is used for controlling dynamic switching between a zero dispersion state and a preset non-zero dispersion state by introducing dispersion into a link, and an output optical signal port of the adjustable dispersion compensation module is optically connected with a receiving port of the optical module; and the radio frequency output end of the optical module is electrically connected with the oscilloscope. According to the invention, the problems of long chirp parameter test time and high measurement cost in the prior art are solved, and the chirp parameter measurement method has the characteristic of being capable of realizing rapid and accurate chirp parameter measurement.

The invention discloses a directly-modulated wavelength scanning light source device which comprises a pulse control unit, a semiconductor laser, a thermoelectric refrigerating unit, a temperature measuring element, a temperature control system, a coupler, a wavelength calibration element, a photoelectric detector and a wavelength correction system. The pulse control unit drives the semiconductor laser, the semiconductor laser is connected with a first input end of the coupler, a first output end of the coupler is connected to the wavelength calibration element, a second input end of the coupler is connected with the photoelectric detector, and the photoelectric detector is connected with the pulse control unit. A second output end of the coupler is a wavelength scanning light source output end, and the photoelectric detector is connected with the wavelength correction system. The device realizes a light source in a wavelength scanning range from several nm to dozens of nm at a wavelength scanning rate as high as MHz and above, realizes wavelength scanning in each wave band range based on a directly modulated laser, and is beneficial for adapting to more optical fiber sensing high-speed measurement application occasions.

The invention relates to a transition carrier structure for improving the packaging bandwidth of a directly modulated laser chip. The transition carrier structure comprises a first transition carrier transmission structure, a second transition carrier transmission structure and a gold bonding wire. The first transition transmission carrier structure comprises a first ground electrode, a first signal transmission line and a first ground accompanying hole, and the second transition carrier structure comprises a second ground electrode, a second signal transmission line and a second ground accompanying hole. The first transition carrier structure and the second transition carrier structure are connected through gold bonding wires. The transition carrier packaging structure provided by the invention can be well applied to packaging of a laser chip, compensation transition area welding and electric parasitic parameters introduced by gold wire bonding, and reduction of loss generated in a signal transmission process, so that the packaging bandwidth of the laser chip is improved.

This invention relates to a machine learning-based modeling method for cloud wireless access networks, comprising: acquiring a remote cloud wireless access network transmitter; improving the remote cloud wireless access network transmitter by replacing the traditional microwave source with a dual-ring opto-oscillator to suppress side modes through single-mode oscillation; and introducing a directly modulated laser after an arbitrary waveform generator to utilize the chirp effect and fiber dispersion to generate power gain; and modeling the millimeter-wave signal spectrum of the improved remote cloud wireless access network transmitter based on a lightweight gradient booster model to match the dimensions of input and output features. This invention uses a dual-ring opto-oscillator to replace the traditional microwave source, reducing phase noise; utilizes the synergistic gain behavior of the directly modulated laser chirp and fiber dispersion to improve the transmission gain of the millimeter-wave signal; and models the spectral characteristics of the millimeter-wave signal using a lightweight gradient booster model to achieve spectrum prediction.

A controller stabilizes a distributed feedback plus reflection (DFB+R) laser, which has a back facet, a DFB section, a passive section, and a front facet with a low reflective element. An etalon filter is formed by a portion of the DFB section, the passive section, and the low reflective element. Control circuitry directly modulates the DFB section with a modulation signal and biases the passive section with a bias signal. In operation, a lasing mode of the DFB section is aligned to a long wavelength edge of one of the periodic peaks of a reflection profile of the etalon filter. Meanwhile, photodiodes are arranged to monitor the output power emitted from the laser's front and back facets. The control circuitry monitors a ratio of the detected output power and adjusts the bias based on the monitored ratio.

A laser includes a substrate, a first cladding and a second cladding, a gain medium, and a plurality of supports. The first cladding is spaced apart from the substrate by an air gap. The first cladding has a thickness in a vertical direction in a range from 0.05 microns to 0.15 microns. The gain medium is disposed on the first cladding opposite the air gap. The second cladding is disposed on the gain medium opposite the first cladding. The second cladding has a thickness in the vertical direction in a range from 0.05 microns to 0.15 microns. The supports are coupled to each of the substrate, the first cladding, the gain medium, and the second cladding to hold the first cladding, the gain medium, and the second cladding spaced apart from the substrate.

The invention discloses a direct modulation laser array chip and a manufacturing method thereof, and relates to the technical field of semiconductor laser manufacturing, the direct modulation laser array chip is internally provided with at least two input paths and one output path, and all the input paths are jointly coupled to one output path to form a laser array. Each input path is internally provided with a laser unit and a grating structure capable of forming an equivalent FP feedback cavity with the laser unit, the grating structure is formed by etching a grating material according to a preset pattern, and the grating material is etched to penetrate through the grating structure and extend into the spacing layer below the grating structure; according to the technical scheme, the optical resonance effect can be introduced into the laser array, meanwhile, a plurality of grating structures with different reflectivity are obtained in single etching in a mode of combining electron beam exposure and dry etching, and the process complexity of chip manufacturing is reduced.

An H-bridge integrated laser driver optimizes power consumption, impedance matching, low-swing and high-swing reliability for electro-absorption modulated laser (EML) and direct modulated laser diode (DML) applications, VCSEL / silicon photonics, and other applications requiring high-swing drivers or control of impedance. The laser driver includes a retimer for converting low-speed parallel data into a high-speed serial bit stream and an inverted representation of the high-speed parallel bit stream, an M-bit PMOS DAC configured to receive a first buffered bit stream, an N-bit NMOS DAC configured to receive a second buffered bit stream substantially synchronized with the first buffered bit stream. A protection device is coupled between the M-bit DAC and the N-bit DAC. A first DC level shift pre-driver array is coupled between the retimer and the M-bit DAC to receive the high-speed parallel bit stream and the inverted high-speed parallel bit stream, and a second DC level shift pre-driver array is coupled between the retimer and the N-bit DAC to receive the high-speed parallel bit stream and the inverted high-speed parallel bit stream. An impedance matching module is coupled to an output of the protection device. The laser driver can be integrated on a CMOS communication chip.

The invention provides a directly modulated laser, which comprises a substrate, an epitaxial layer, a buffer layer, a grating layer, a lower limiting layer, an active layer, an upper limiting layer, a corrosion cut-off layer, a cladding and a contact layer, the structure of the grating layer is a convex grating structure with a lambda / 8 phase shift, the grating layer is located on the N-type doped side, and the convex grating structure with the lambda / 8 phase shift is used for reducing the photon density at the phase shift position through the negative reflector loss feedback effect and limiting hole gathering on the P-type doped side through the characteristic that the electron mobility is larger than the hole mobility.

The utility model relates to an optical signal transmission device. The optical signal transmission device comprises an optical transmitter, a connector and an optical receiver. The light emitter comprises four direct modulation lasers which are arranged in parallel; the output end of each direct modulation laser is connected with one end of the connector, and the other end of the connector is connected with the optical receiver. The four direct modulation lasers with the 25G bandwidth can be arranged in parallel to form the four-carrier parallel O-band DWDM optical module with the 100G bandwidth, so that the four direct modulation lasers can be integrated in one O-band DWDM optical module, and the integration level of the O-band DWDM optical module can be improved.

A transmitting apparatus includes a direct modulation laser, a branching unit, a first signal generation unit, a second signal generation unit, and a polarized wave multiplexing unit. The branching unit branches continuous phase frequency shift keying signal light having been generated by the direct modulation laser by applying a first modulation signal into first branch light and second branch light. The first signal generation unit generates first polarized wave signal light obtained by removing an intensity modulation component having been generated by the direct modulation laser by applying the first modulation signal from the first branch light. The second signal generation unit generates second polarized wave signal light obtained by removing the intensity modulation component from the second branch light and adding an intensity modulation component to the second branch light by applying a second modulation signal, the second polarized wave being orthogonal to the first polarized wave. The polarized wave multiplexing unit multiplexes the signal light for the first polarized wave and the signal light for the second polarized wave.

The invention relates to a cloud wireless access network modeling method based on machine learning, and the method comprises the steps: obtaining a remote cloud wireless access network transmitter, improving the remote cloud wireless access network transmitter, replacing a conventional microwave source of the remote cloud wireless access network transmitter with a double-ring photoelectric oscillator, and suppressing a side mode through single-mode oscillation, a direct modulation laser is introduced behind the arbitrary waveform generator and is used for generating power gain by utilizing a chirp effect and optical fiber dispersion cooperative gain; and based on a lightweight gradient elevator model, modeling a millimeter wave signal spectrum of the improved remote cloud wireless access network transmitter, and matching input feature dimensions and output feature dimensions. According to the invention, the dual-ring photoelectric oscillator is adopted to replace a traditional microwave source, so that phase noise is reduced; a cooperative gain behavior of directly modulating laser chirp and optical fiber dispersion is utilized to improve millimeter wave signal transmission gain; the spectral characteristics of millimeter wave signals are modeled through a lightweight gradient elevator model, and spectrum prediction is realized.

The present invention discloses an optical digital-to-analog conversion system based on a direct-modulated laser and an optical coupler array, which includes a digital signal array, a direct-modulated laser array, an optical fiber delay array, an optical coupler array, an optoelectronic filter and a control system, wherein the digital signal array generates a binary electrical digital quantity to be converted, which is converted into an optical signal by the direct-modulated laser array, enters the optical fiber delay array for time alignment, and then is converted into an analog optical power signal after coupling and beam splitting by the optical coupler array, and finally the optical beat frequency signal is filtered out by the optoelectronic filter to output an analog optical signal, and the control system controls the output power of each laser in the direct-modulated laser array to be equal and stable, so that the output analog signal meets the conversion requirements. The analog-to-digital conversion method used by the optical digital-to-analog conversion system of the present invention is implemented in the optical domain through a 2×2 optical coupler array, and is not limited by the bandwidth of electronic devices.

A microwave photon broadband weak signal receiving device comprises a direct modulation laser, a light adjustable attenuator, a photoelectric detector, a first amplifier, a first power divider, a spectrum analyzer, a second amplifier, a filter and a second power divider. The direct modulation laser, the light adjustable attenuator, the photoelectric detector, the first amplifier, the first power divider, the second amplifier, the tunable filter and the second power divider are sequentially connected end to end to form a photoelectric oscillation loop. Compared with the prior art, the input signal is coupled into the photoelectric oscillation loop, the photoelectric oscillation loop is in a critical oscillation starting state by controlling the gain of the photoelectric oscillation loop, the oscillation signal is generated by utilizing the interaction between light and an electric signal, and the signal is amplified, filtered and the like. High-efficiency identification and receiving processing of weak signals are realized, and stability and reliability of signal receiving are improved.

Photonics has become a dominant or evolving technological solution for communications to meet the increasing demand for bandwidth. Accordingly, photonic communications is moving towards coherent modulation formats to further increase capacity by encoding information in both phase and amplitude of the optical signal. Whilst coherent optical transmitters and coherent optical receivers are more complex than their on-off counterparts leveraging monolithic photonic elements and photonic integrated circuits employing said photonic elements offers a lower cost route for coherent optical components. Further, external modulation, using phase modulators or amplitude modulators or a combination thereof, can increase modulation bandwidth relative to directly modulated lasers for increased data transmission. Novel optical hybrid circuits and external modulators are present which are compatible photonic integrated circuit manufacturing techniques and monolithic integration.

A communication system is provided with: a direct modulation laser that outputs an optical signal carrying information to be delivered; an injection circuit that injects a current into the direct modulation laser; a control unit that controls an operation of the direct modulation laser by controlling an operation of the injection circuit; and a reception device that receives the optical signal. The direct modulation laser is provided with: a laser active region of a distributed feedback type; and an optical feedback region that is optically connected to one end, in a waveguide direction, of the laser active region and that has an optical waveguide structure in which a reflection point is formed in the waveguide direction. The control unit causes the direct modulation laser to operate under a plurality of predetermined mutually-different conditions, and causes the direct modulation laser to output the optical signal for conveying the information under each of the conditions.

A dual output directly modulated laser device is provided that generates two distinct optical output signals. The dual output directly modulated laser device includes two outer gain sections, each directly modulated by injection of a respective modulation current. The dual output directly modulated laser device further includes a central section including a distributed reflector providing optical feedback to both outer gain sections while preventing the generation of stimulated photons. The two outer gain sections form two laser cavities each configured to emit a directly modulated signal as an optical output signal in a direction away from the central section. The dual output directly modulated laser device can simultaneously be used for main-PON upstream and sub-PON downstream transmission, thus, with this enhanced functionality, the laser device makes a passive optical network architecture more energy efficient by reducing power consumption and implementation cost as well.

A drive circuit for a direct modulated laser and a direct modulated optical transmitter. The drive circuit includes a service data drive unit, a voltage configuration unit, a monitoring data modulation unit, and a monitoring current generation unit. Output terminals of the voltage configuration unit and the monitoring data modulation unit are connected to a same input terminal of the monitoring current generation unit. An output terminal of the service data drive unit is connected to a current sink interface of the monitoring current generation unit, and is suitable for connecting a direct modulated laser. In the technical solution, a low-speed monitoring data signal is mixed into an average optical power signal of a high-speed service data light wave from the direct modulated laser, then is extracted from the received optical signal by a remote optical receiver, enabling the drive circuit to be remotely monitored.

Systems may include one or more directly modulated laser (“DML”) optical transmitters to transmit optical signals carrying data to one or more optical receivers and include one or more filters designed to reduce the power in lower modulation levels. In various embodiments, the optical receiver includes an optical combiner to combine local oscillator light at a frequency, fLO with the optical data signal, an optical-electrical converter to downconvert the combined LO-optical signal to an electrical signal including four PAM4 frequencies, an electrical filter to attenuate the electrical power in the PAM4 frequencies by differing amounts, rectify and output the electrical signal. Systems may include extinction ratio management and thermal chirp compensation, and may include optical filters designed for chirp management with different laser parameters (α and k) and OMAs with PAM-M format in both optical and electrical domains and for use with quasi-coherent receivers (QCR) and DML transmitters.

Photonics has become a dominant or evolving technological solution for communications to meet the increasing demand for bandwidth. Accordingly, photonic communications is moving towards coherent modulation formats to further increase capacity by encoding information in both phase and amplitude of the optical signal. Whilst coherent optical transmitters and coherent optical receivers are more complex than their on-off counterparts leveraging monolithic photonic elements and photonic integrated circuits employing said photonic elements offers a lower cost route for coherent optical components. Further, external modulation, using phase modulators or amplitude modulators or a combination thereof, can increase modulation bandwidth relative to directly modulated lasers for increased data transmission. Novel optical hybrid circuits and external modulators are present which are compatible photonic integrated circuit manufacturing techniques and monolithic integration.

The present application discloses a directly modulated laser array chip and a method for manufacturing the same, relating to the technical field of semiconductor laser manufacturing. The directly modulated laser array chip is provided with at least two input paths and one output path. All input paths are coupled together into one output path to form a laser array. Each input path is provided with a laser unit and a grating structure capable of forming an equivalent FP feedback cavity therewith. The grating structures are formed by etching a grating material according to a predetermined pattern, and the etching passes through the grating structure and extends into the underlying spacer layer. The technical solution of the present application can introduce an optical-optical resonance effect into the laser array while obtaining multiple grating structures with different reflectivities in a single etching process by combining electron beam exposure and dry etching, thereby reducing the process complexity of chip manufacturing.

The invention discloses a nonlinear distortion suppression method and device for an optical single-side-band transmitter based on an electro-absorption modulated laser. A digital pre-distortion model containing second-order nonlinearity and intermodulation distortion of a direct modulated laser and an electro-absorption modulator is established in a digital domain; and a cost function is constructed in combination with an actual output spectrum, and a model coefficient is adaptively iteratively updated, so that the optical single-side band signal output by the transmitting end realizes forward compensation on a main nonlinear component before transmission, and the transmission efficiency is improved on the premise that an additional optical device and a complex receiving end balance structure are not required to be increased. According to the optical single-side-band transmitter, nonlinear distortion and intermodulation distortion caused by cascade modulation are effectively suppressed, the linearity and the adjacent channel power ratio of the optical single-side-band signal are remarkably improved, the signal-to-noise ratio and the bit error rate performance of the system are improved, and the transmission capacity and the engineering practicability of the optical single-side-band transmitter in a medium-long-distance high-speed optical interconnection scene are enhanced.

The invention discloses a laser radar signal generation method, a laser radar signal detection method and a laser radar signal detection system. The system comprises a transmitting end and a receiving end, the transmitting end comprises a transmitting end modulation module used for generating a first electric driving signal and a target modulation reference signal; the direct modulation module directly modulates the first electric driving signal to generate a calibration electric signal; the pre-distortion equalization module compares the calibration electric signal with the modulation reference signal to generate a second electric driving signal; the beam transmitting module adopts a second electric driving signal to drive a direct modulation laser to generate radar detection signal light to be transmitted; the receiving end comprises a beam receiving module used for receiving reflected signal light after the radar detection signal light is reflected by a target; the coherent detection module performs coherent mixing on the reflected signal light and the transmitted signal light to obtain an electric signal; the phase recovery module obtains a signal after phase recovery according to the electric signal; the distance analysis module estimates the distance of the target; the Doppler processing module estimates a relative velocity of the target.