60results about "Laser output parameters control" patented technology

A semiconductor laser chip (1) comprising a semiconductor body with a sequence of semiconductor layers (2) having an active region (20) for generating radiation is specified, wherein the semiconductor body has a resonator region (3) with the active region (20) and a diode region (4) spaced apart from the resonator region (3), wherein the active region (20) of the resonator region (3) and the diode region (4) are connected antiparallel to each other with respect to their forward direction. Furthermore, a semiconductor laser arrangement (10) with a semiconductor laser chip (1) is specified.

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.

An optical device includes a generator, a light emitter, a modulator, an optical amplifier, a current source, a storage, and a controller. The generator generates an electric signal of a multilevel amplitude modulation method. The light emitter emits laser light. The modulator modulates the laser light using the electric signal and outputs an optical signal. The optical amplifier optically amplifies the modulated optical signal according to a drive current. The current source adjusts the drive current to be supplied to the optical amplifier. The storage previously stores an information with respect to input-output characteristics of the optical signal in the optical amplifier relative to drive current value of the drive current. The controller acquires, from the storage, the input-output characteristics corresponding to the drive current value of the drive current supplied to the optical amplifier and controls the electric signal based on the acquired input-output characteristics.

This invention discloses a Littrow-type cavity length-compensated mode-hopping-free continuously tunable semiconductor laser, comprising a laser diode (1), a collimating lens (2), and a diffraction grating (3). Mode-hopping-free continuous tunability is achieved through a micro-elastic material base (4). The micro-elastic material base (4) is hollowed out to create a movable block (401) that can be driven by a piezoelectric ceramic (5), an isosceles triangular groove (404), and a pair of waist arms (406), enabling micro-displacement and micro-angle changes in the waist arms (406), thereby achieving continuous tunability of the output laser. This invention achieves mode-hopping-free continuous tunability of the laser output through an innovative combination of a special mechanical structure and the frequency selection characteristics of the grating. The structure is compact and highly stable, ultimately resulting in a mode-hopping-free continuously tunable external cavity semiconductor laser that meets the requirements of high-end precision measurement.

This invention discloses an integrated miniaturized atomic magnetometer and its non-magnetic VCSEL laser module, including a VCSEL chip, a heating coil, a current source, a signal source, and a power amplifier. The AC signal output from the signal source is amplified by the power amplifier with an adjustable amplification factor and then output to the heating coil to heat the VCSEL chip. It also includes a PID controller; by detecting the voltage across the input current of the VCSEL chip or by detecting the voltage across the heating coil, the power amplifier is controlled by the PID controller to achieve VCSEL chip temperature control. This avoids the magnetic field inherent in the device itself directly affecting the sensitivity of the atomic magnetometer and interfering with the measurement results. It also reduces the size of the laser module and the integrated atomic magnetometer.

A directly modulated light source includes: a horizontal laser diode including a horizontal PIN junction, the horizontal junction being formed of an intrinsic zone arranged between a first p-doped zone and a first n-doped zone, the intrinsic zone including quantum wells; a vertical PIN junction formed of the intrinsic zone arranged between a second p-doped zone and a second n-doped zone, the latter zone being arranged on the substrate side; the vertical junction being reverse biased and modulates the light emitted by the horizontal laser diode by the Stark effect in the quantum wells; a blocking layer arranged beneath the first p-doped zone and to prevent current leakage between the first p-type doped zone and the second n-doped zone.

A laser display system 100 is configured to increase the dynamic range of a laser diode by modulating an operating current applied to the laser diode based on a desired sequence of brightness levels and a temperature of the laser diode. In some embodiments, a measuring circuit measures a voltage of the laser diode at a given current, which indirectly indicates the temperature of the laser diode, thus obviating the need for a direct measurement of temperature. In addition, in some embodiments, the measuring circuit identifies a threshold current of the laser diode based on a range of current values at which values of the current multiplied by the derivative of the voltage against the current vary relatively rapidly. By compensating for temperature effects and identifying the threshold current, a driver of the laser diode more precisely controls light output of the laser diode across an increased dynamic range.

The invention discloses a laser power automatic adjusting method and system in a remote foreign matter removing process of a power transmission line, and the method comprises the steps: recognizing and positioning a foreign matter through an inspection image, analyzing the spatial position relation between the foreign matter and a power transmission line, preliminarily judging the contact state of the foreign matter, and outputting a contact risk level; analyzing the foreign matter, and constructing an initial thermal coupling risk parameter based on the contact risk level; controlling the laser to perform short-time irradiation on the foreign matter for a preset time length at the tentative power, and synchronously collecting thermal response characteristic information generated by the surface of the foreign matter in the irradiation process; based on the thermal response feature information, comparing with a preset thermal response reference model, dynamically judging the actual thermal coupling state between the foreign matter and the power transmission conductor, and correcting the initial thermal coupling risk parameter in real time according to a judgment result to obtain a corrected thermal coupling risk parameter; and according to the corrected thermal coupling risk parameter, gradually increasing the laser power of the laser to an effective clearing power interval so as to complete foreign matter clearing.

The application discloses a kind of multi-wavelength adjustment system and method, the system includes: multiple different wavelength laser chips, be set on multiple heat dissipation substrates;Heating block is in high temperature state, and is connected with the heat dissipation substrate by multiple gold wires;Wherein, the multiple gold wires are specifically used for: the heat of heating block is introduced into chip by gold wire, form heat gradient, by adjusting the number and length of the multiple gold wires, change the temperature difference between the heating block or laser chip and the heat dissipation substrate, to change the wavelength of the multiple different wavelength laser chips, so that the wavelength of chip is regulated and corrected, and scheme is easy to operate, and cost is lower.

This specification discloses a method for adjusting laser power during remote foreign object removal from power transmission lines. The method includes: acquiring real-time images of the laser operation area and forming a continuous video stream; identifying and classifying multiple objects within the area covered by the real-time images; for each identified object, associating a maximum tolerable laser power based on its material properties, wherein the maximum tolerable laser power is determined based on the material damage energy threshold, the laser irradiation time on the object, and the laser spot area; determining a collimator neighborhood region centered on the current laser emission point, and analyzing the power tolerance of different objects within this region based on the associated maximum tolerable laser power; calculating the maximum permissible safe output power at the current moment based on the laser's current motion direction, tracking speed, and the local safe power distribution; and dynamically adjusting the laser's output power in real time based on the maximum safe output power.

An optical semiconductor device according to the present disclosure includes a semiconductor substrate, at least one semiconductor laser provided on the semiconductor substrate, an optical multiplexer / demultiplexer circuit provided on the semiconductor substrate, multiplexing or demultiplexing first output light of the semiconductor laser and outputting second output light and third output light, a first waveguide portion provided on the semiconductor substrate, and outputting the second output light from an end face of the semiconductor substrate, and a second waveguide portion including an optical amplifier amplifying the third output light and a reflecting portion and provided on the semiconductor substrate, wherein the reflecting portion includes a diffraction grating that reflects the third output light amplified by the optical amplifier to feed back to the semiconductor laser via the optical amplifier and the optical multiplexer / demultiplexer circuit, and the semiconductor laser and the reflecting portion form a resonator.

A Laser System In certain applications it is desirable to monitor the output laser power of a laser system to assess system performance but also to provide an early indication of system degradation or failure. This is typically achieved using an internal detector configured to pick off a portion of the laser's output beam to measure laser power accurately. This naturally reduces the useable output power of the laser system. There is described a laser system that includes sensors which monitor the temperature and electrical usage characteristics, e.g. voltage across and / or current through, of components of the laser system, and a machine learning model trained to predict the laser's optical output power using only the temperature and electrical usage readings as inputs. The model can predict laser output power from thermal and electrical measurements alone thus obviating the need of a pick-off system.

The present disclosure provides a laser power correction method, device, and laser for suppressing relaxation oscillation. The method includes: setting the laser to a first duty cycle and a first frequency, adjusting current so that the average power is a preset power, and recording the present current value; adjusting the frequency so that the average power is the preset power, recording all frequency values to obtain a frequency interval; changing the duty cycle to obtain frequency intervals at various duty cycles; setting the laser to a second duty cycle and the representative frequency, adjusting the current so that the average power is the minimum / maximum average power, recording the minimum and maximum currents, and determining a current-average power relationship; changing the duty cycle to obtain the current-average power relationship at various duty cycles and in different frequency intervals. The present disclosure is applicable to a pulsed laser control method that adds a small step signal to suppress relaxation oscillation. The current-average power relationship is determined by actually measuring the power output value, thereby achieving accurate correction of the laser.

An optically pumped solid state laser (OPSL) module is disclosed. A submount unit is provided having raised wedged portion(s) to accommodate at least one gallium and nitrogen (GaN) containing pump laser diode. The at least one GaN pump laser diode is mounted on a wedge such that the light emission points at a downward angle, through beam shaping optics, and onto a GaN gain chip that is placed on a centerpiece platform representing a space between the lower portion of the one or more wedged portion(s). The gain chip is made of a series of spacer and active regions, all epitaxially formed, so that upon pumping from the pump laser diode(s), there is photonic emission from the gain chip. The gain chip spacer and active regions are selected based upon the desired wavelength output. Each active region may be spaced apart based on a half-wavelength metric.

This invention relates to an orange-light-emitting zinc oxide quantum dot based on high fluorescence quantum yield. It is synthesized in situ by adding a red fluorescent dye potassium hydroxide methanol mixture to an anhydrous methanol solution of zinc acetate and directly precipitating the particles at 62-64°C. The resulting zinc oxide composite nanomaterial has long-wavelength emission and high fluorescence quantum yield. It can be used as a phosphor in laser diodes to achieve white light emission, thus broadening the application of zinc oxide in optoelectronic devices.

Example embodiments relate to light detection and ranging (lidar) devices or other apparatus that incorporate laser light emitters capable of increased pulse energies and decreased pulse durations. These laser light emitters include a gain medium having two portions to which a pump electrode and a switch electrode, respectively, are coupled. The pump electrode is configured to apply a current through the gain medium that provides energy for lasing and the switch electrode is configured to apply a current through the gain medium that controls a transparency of the second portion of the gain medium. Thus the switch electrode, which controls the timing of emitted light pulses, can be driven by a lower current and thus have shorter pulse widths, rise time, and / or fall times, thereby allowing for shorter, higher-energy laser pulses to be emitted.

The present invention relates to an electro-absorption modulated laser (EML) diode including a laser diode formed on one side of a substrate, an electro-absorption modulator (EAM) formed on the other side of the substrate, and an anti-parallel (AP) diode integrated with a bias and a radio frequency (RF) feeding line at a front stage of the EAM.

The present disclosure provides a laser power correction method, device, and laser for suppressing relaxation oscillation. The method includes: setting the laser to a first duty cycle and a first frequency, adjusting current so that the average power is a preset power, and recording the present current value; adjusting the frequency so that the average power is the preset power, recording all frequency values to obtain a frequency interval; changing the duty cycle to obtain frequency intervals at various duty cycles; setting the laser to a second duty cycle and the representative frequency, adjusting the current so that the average power is the minimum / maximum average power, recording the minimum and maximum currents, and determining a current-average power relationship; changing the duty cycle to obtain the current-average power relationship at various duty cycles and in different frequency intervals. The present disclosure is applicable to a pulsed laser control method that adds a small step signal to suppress relaxation oscillation. The current-average power relationship is determined by actually measuring the power output value, thereby achieving accurate correction of the laser.

The application provides an external cavity tuning semiconductor laser and a uniform wave number synchronous output method thereof, rapid and accurate modulation of the angle of a feedback light beam is realized through rapid deflection of an optical galvanometer, and the method specifically comprises the following steps: synchronously collecting the deflection angle of the optical galvanometer and the instantaneous output spectrum, accurately calculating the center wavelength of each sampling point by using a Gaussian fitting method, converting the center wavelength to the wave number domain for uniform processing, and obtaining the optimized driving curve of the deflection angle of the optical galvanometer changing with time through reverse calculation, so that the laser is finally synchronously and rapidly output according to the uniform wave number; the application can effectively overcome the deficiencies of traditional motor driving or piezoelectric ceramics in terms of precision, tuning speed and scanning stroke, significantly reduce the hardware cost of the core component, and has a wide application in the scenes of coherent tomography, high-resolution spectral analysis and precise laser radar.

This paper provides an improved external cavity laser (1) comprising a gain section (2) and an external cavity passive chip (3), the external cavity passive chip having a first end (31) optically coupled to the gain section (2) and a second end (35) providing 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 application discloses a semiconductor optical device and an optical signal modulation method. The semiconductor optical device comprises an integrated multi-section serial laser based on a same active region, and is used for emitting optical signals of different lasing wavelengths through a same lasing end face in different time periods of a modulation period in an application scenario of a frequency-modulated continuous wave signal. In one modulation period, each section of the multi-section serial laser independently emits an optical signal of a specific wavelength and keeps continuous wave operation, so as to realize frequency-modulated output of a certain time proportion and jointly form a modulation signal of a complete period. Through the application, the technical problem that the semiconductor optical device in the related art has high complexity and poor stability of an optical detection system due to the need of introducing multiple lasers is solved.

A multi-pass cavity-based optical pulse contrast enhancement device is disclosed which selectively attenuates prepulses and other undesired low-power pulse features. The device may include two or more optical mirrors, an intracavity nonlinear medium, and a spatial filtration arrangement that may be inside or outside of the cavity. The nonlinear medium enables a cavity configuration where low-power pulse features may be cavity-unstable and / or mode-mismatched whereas the high-power region may be cavity-stable and / or mode-matched. Propagation through the cavity distinguishes the low-power and high-power pulse regions in their spatial beam characteristics, enabling low-power suppression via diffraction losses, beam distortion, or spatial filtration. This improves upon prior solutions in that it improves pulse contrast by several orders of magnitude at high main pulse transmission efficiency, preserves near-diffraction limited beam quality, is compatible with high laser average powers and pulse repetition rates, and is configurable to accommodate high, e.g., multi-Joule pulse energies.

The application provides an external cavity laser and a temperature control method, and relates to the technical field of lasers; the optical filtering feedback module and the laser chip of the external cavity laser are arranged in a packaging shell; the optical filtering feedback module is used for mode selection of an emission light signal emitted by the laser chip so that the laser chip performs mode locking on a feedback light signal output; a temperature controller controls a temperature adjusting unit to adjust the temperature in the packaging shell according to a monitoring result of a first temperature monitoring device on the temperature in the packaging shell; the temperature controller controls the temperature adjusting unit to adjust the temperature of the optical filtering feedback module according to a monitoring result of a second temperature monitoring device on the optical filtering feedback module, so that the temperature in the packaging shell and the temperature of the optical filtering feedback module both meet preset requirements and the device temperature difference of the optical filtering feedback module meets an expected temperature difference. The embodiment of the application can output more stable laser power and wavelength when the temperature difference between the inside and outside of the packaging shell is large.

To provide an optical sensor ensuring durability.SOLUTION: An optical sensor includes: a light projection section for generating light projection beams by a light source element; a light reception section for outputting a detection signal by receiving reflection beams; and a control section for controlling the light projection section and the light reception section. The control section is configured to execute monitoring of a heat propagation temperature Tt propagated to the periphery of the light source element in the light projection section, and controlling of light emission output Pl in the light source element so as to absorb an efficiency change amount of light emission efficiency that decreases according to an increase in the heat propagation temperature Tt in the light source element and a temperature change amount of a junction temperature Tj in the light source element so as to be correlated with the heat propagation change amount of the heat propagation temperature Tt.SELECTED DRAWING: Figure 9

The invention relates to a directly modulated light source (DMD) comprising: - a horizontal laser diode (DH) comprising a horizontal PIN junction (HJ), the horizontal junction being formed of an intrinsic region (Zi) disposed between a first p-doped region (Zp1) and a first n-doped region (Zn1), the intrinsic region comprising quantum wells; - a vertical PIN junction (VJ) formed of said intrinsic region disposed between a second p-doped region (Zp2), and a second n-doped region (Zn2) disposed on the substrate side; the vertical junction being reverse biased and modulates said light emitted by the horizontal laser diode by Stark effect in the quantum wells; - a blocking layer (CB) disposed under the first p-doped region and configured to prevent current leakage between the first p-doped region and the second n-doped region.

An optical telecommunications network (100) comprising a / an: Ultra-Stable Signal Optical Source, USS-OS (105), for generating an Ultra-Stable Optical Signal (130), USOS; first Interferometric Stabilisation Device (110-1), ISD, connected to the USS-OS; second ISD (110-2) arranged remotely to the USS-OS and the first ISD; first Optical Link (120-1), OL, connecting an output of the first ISD to a first endpoint (115-1), wherein said first OL is bidirectional; second OL (120-2) connecting the USS-OS to the second ISD; and bridging OL (160-1) arranged proximate the first endpoint and configured to connect the first OL to the second ISD; wherein: the first ISD is configured to: receive, as an input, the USOS from the USS-OS (310); output, to the first OL, a first modified USOS (260-1) by performing a first frequency shift upon the input USOS (320); determine a first Noise Value, NV, associated with the first OL from interferometric processing of the USOS and a first return USOS (265-1), from the first endpoint, or proximate thereto, of the first modified USOS; and subsequently correct the first modified USOS by modifying the first frequency shift so as to counteract the determined first NV, thereby to output a first corrected USOS (370); and the second ISD is configured to: receive (510), as an input, a: from the bridging OL, first noisy USOS (420-1) that is the first modified USOS (260-1) as affected by the first NV due to the first OL; and a second noisy USOS (405-2) that is the USOS as affected by a second NV due to the second OL; generate a second modified USOS (260-2) by performing a second frequency shift, different to the first frequency shift, upon the second noisy USOS (520); determine the second NV from interferometric processing of the first noisy USOS and the second modified USOS; and subsequently correct (560) the second modified USOS by modifying the second frequency shift so as to counteract the determined second NV, thereby to output a second corrected USOS (420-2).