488 results about "Multi wavelength laser" patented technology

The present invention is an alternative Fourier domain optical coherence system (FD-OCT) and its associated method. The system comprises a swept multi-wavelength laser, an optical interferometer and a multi-channel receiver. By employing a multi-wavelength laser, the sweeping range for each lasing wavelength is substantially reduced as compared to a pure swept single wavelength laser that needs to cover the same overall spectral range. The overall spectral interferogram is divided over the individual channels of the multi-channel receiver and can be re-constructed through processing of the data from each channel detector. In addition to a substantial increase in the speed of each axial scan, the cost of invented FD-OCT system can also be substantially less than that of a pure swept source OCT or a pure spectral domain OCT system.

A multi-wavelength laser device includes at least two of a blue laser diode, a red laser diode, and an infrared laser diode, which are arranged in the same direction on the same base. One laser light emission point is arranged behind another in increasing order of wavelengths of the laser diodes.

The present invention is an alternative Fourier domain optical coherence system (FD-OCT) and its associated method. The system comprises a swept multi-wavelength laser, an optical interferometer and a multi-channel receiver. By employing a multi-wavelength laser, the sweeping range for each lasing wavelength is substantially reduced as compared to a pure swept single wavelength laser that needs to cover the same overall spectral range. The overall spectral interferogram is divided over the individual channels of the multi-channel receiver and can be re-constructed through processing of the data from each channel detector. In addition to a substantial increase in the speed of each axial scan, the cost of invented FD-OCT system can also be substantially less than that of a pure swept source OCT or a pure spectral domain OCT system.

An apparatus and method providing a plurality of modulated optical beams from a single layer of semiconductor material. For one example, an apparatus includes a plurality of optical waveguides disposed in a single layer of semiconductor material. Each one of the plurality of optical waveguides includes an optical cavity defined along the optical waveguide. A single bar of gain medium material adjoining the single layer of semiconductor material across the plurality of optical waveguides is included. The gain medium-semiconductor material interface is defined along each of the plurality of optical waveguides. A plurality of optical modulators is disposed in the single layer of semiconductor material. Each one of the plurality of optical modulators is optically coupled to a respective one of the plurality of optical waveguides to modulate a respective optical beam directed from the optical cavity.

The present invention is a tunable semiconductor laser for swept source optical coherence tomography, comprising a semiconductor substrate; a waveguide on top of said substrate with multiple sections of different band gap engineered multiple quantum wells (MQWs); a multiple of distributed feedback (DFB) gratings corresponding to each said band gap engineered MWQs, each DFB having a different Bragg grating period; and anti-reflection (AR) coating deposited on at least the laser emission facet of the laser to suppress the resonance of Fabry-Perot cavity modes. Each DFB MQWs section can be activated and tuned to lase across a fraction of the overall bandwidth as is achievable for a single DFB laser and all sections can be sequentially activated and tuned so as to collectively cover a broad bandwidth, or simultaneously activated and tuned to enable a tunable multi-wavelength laser. The laser hence can emit either a single lasing wavelength or a multiple of lasing wavelengths and is very suitable for swept-source OCT applications.

The invention relates to a sensing method with an optical-fiber Bragg grating laser device. An optical-fiber Bragg grating is used as a reflector of the resonant cavity, an active optical fiber capable of generating sufficient gains is added, and a double wavelength / multiple wavelength optical-fiber Bragg grating laser device is formed under the action of a pump light source and used as a sensor. When the outside strain, temperature and other physical quantities act on the sensing system, the beat signal frequency among the double wavelength or multiple wavelength laser can shift, and counter stress, temperature and other physical parameters can be measured precisely by detecting the beat signal frequency information. The invention has the advantages of simple manufacture, stable and reliable operation, stable measurement result and high precision, and is free from the interference of light intensity, polarization and other optical information quantities. The multipoint distribution sensing measurement can be realized in a frequency-division multiplexing mode. An electrooptical modulator is added before the spectrum analyzer starts detection so as to randomly adjust the beat signal frequency, thereby greatly reducing the spectral range of the spectrum analyzer and reducing the detection cost.

The invention provides a laser system (100) wherein the output may be selected from two or more different wavelengths of output laser light. The system (100) comprises a laser capable of having at least two different wavelengths of laser light resonating in the cavity (105) simultaneously. One of the frequencies is generated by a Raman crystal (135) which shifts the frequency of light generated by the lasing medium (125). A tunable non-linear medium (140), such as LBO, is provided in the cavity for selectively frequency converting at least one of the at least two different wavelengths of laser light. The conversion may be SHG, SFG or DFG for example. A tuner (145) is provided to tune the non-linear medium to select the particular wavelength to convert. Temperature tuning or angle tuning of the non-linear medium can be used. A Q switch (130) may also be provided in the cavity. The output laser beam can be used for treatment, detection or diagnosis of a selected area on or in a subject, and can be used in opthalmological and dermatological fields.

A multi-wavelength laser source is provided including a pump laser unit, a gain section and an output. The pump laser unit generates an energy signal, which is applied to the gain section. The gain section includes a gain medium with having a superstructure grating forming a distributed Fabry-Perot-like structure. The superstructure grating causes a multi-wavelength laser signal to be generated when the energy signal is applied to the gain medium. The multi-wavelength laser signal is then released at the output.

A light emitting device which can be easily manufactured and can control the positions of light emission precisely, and an optical device. A first and second light emitting elements are formed on one face of a supporting base. The first light emitting element has an active layer made of GaInN mixed crystal on a GaN-made first substrate on the side thereof on which the supporting base is disposed. The second light emitting element has lasing portions on a GaAs-made second substrate on the side thereof on which the supporting base is disposed. Since the first and second light emitting elements are not grown on the same substrate, a multiple-wavelength laser having the output wavelength of around 400 nm can be easily obtained. Since the first substrate is transparent in the visible region, the positions of light emitting regions in the first and second light emitting elements can be precisely controlled by lithography.

Method for manufacturing a monolithic integrated semiconductor laser array, wherein each laser DFB grating structure in the array being sampling Bragg grating structure, the grating of each DFB semiconductor laser waveguide in the array is sampling Bragg grating, and the sampling Bragg grating containing equivalent grating corresponding to the common Bragg grating; the mase wavelength of the DFB semiconductor laser is determined by sampling period of the sampling structure of the sampling Bragg grating within the equivalent grating action bandwidth of the sampling Bragg grating, and it is able to change mase wavelength by changing sampling period. The sampling period is increased or decreased by mask plate with various sampling pattern, and various wavelength mases are implemented by closing in or outlying a center wavelength of the DFB laser mase wavelength, thus to implement multi-channel multi-wavelength laser array; the invention implements various complicated equivalent phase-shift with sub-micron stage accuracy, namely corresponding equivalent grating has Lambada / 4 phase-shift, Lambada / 8 phase-shift and a CPM structure.

Disclosed is an optical time domain reflectometer simultaneously sensing temperature and stress. The system is based on parallel detection of Rayleigh and Brillouin scattered light and includes devices such as a multi-wavelength laser source, a light-pulse modulator, a balance detector, a microwave amplifier, a high-speed data acquisition card, a coupler and a circulator and the like. In the optical time domain reflectometer, the frequency interval of wavelengths of the multi-wavelength laser source is arranged to be in a range of 9-12 GHz, which is equivalent to a frequency shift quantity of Brillouin scattered light in a fiber. A heterodyne coherent detection method is used to carry out parallel detection on Rayleigh and Brillouin scattered spectra and temperature and stress information is demodulated through a Landau-Placzek ratio (LPR) and Brillouin frequency shift distribution; and at the same time, coherent Rayleigh noises are reduced and superposition of the scattered spectra improves the signal-to-noise ratio of the scattered light. The optical time domain reflectometer is capable of realizing simultaneous temperature and stress sensing of a distributed fiber sensing system, improving the signal-to-noise ratio of the scattered light and improving the sensing precision and distance.

The invention discloses a multispectral-based multipoint sampling multiparameter water quality on-line analytical system, comprising an optical system, a waterway system and a detection control system, wherein the optical system is used for scanning the ultraviolet-visible light transmitted spectrum, and fluorescence and Raman emission spectra and the like of a water sample to be detected by adopting a multi-wavelength laser, a pulsed xenon lamp and a charge coupled device (CCD) spectrum detector and converting the scanned spectra into digital signals; and based on multipoint sampling design, the waterway system is used for enabling quantified sewage and clear water to enter into a sampling device through controlling the on and off of a water pump and a solenoid valve so as to realize the collection of the spectroscopic data, moreover, the waterway system has a function of automatically cleaning a sewage pipeline system; and an industrial personal computer is adopted as a core processing unit of the detection control system. The whole system can automatically and continuously operate and is suitable for online analysis.

A temperature controlled welding, soldering and heating system having a plurality of light sources of different wavelengths for simultaneously irradiating a tissue sample and an IR radiometer for providing tissue sample temperature reading in real time, the temperature readings used for controlling the light sources. In a preferred embodiment, the sample is a tissue sample and the light sources are lasers.

A light emitting device which can be easily manufactured and can control the positions of light emission precisely, and an optical device. A first and second light emitting elements are formed on one face of a supporting base. The first light emitting element has an active layer made of GaInN mixed crystal on a GaN-made first substrate on the side thereof on which the supporting base is disposed. The second light emitting element has lasing portions on a GaAs-made second substrate on the side thereof on which the supporting base is disposed. Since the first and second light emitting elements are not grown on the same substrate, a multiple-wavelength laser having the output wavelength of around 400 nm can be easily obtained. Since the first substrate is transparent in the visible region, the positions of light emitting regions in the first and second light emitting elements can be precisely controlled by lithography.

A color dazzle system to enhance area denial to personnel mission for law enforcement, homeland security, border patrol, and the military effectively by interrupting the ability of combatants to continue with their intended mission. The color dazzle system has a multi-wavelength laser module for generate desired color or wavelength ranges of light, a beam projector module for pointing the light towards the target to be dazzled, and a fiber optic beam delivery system for delivering the light to the beam projector module. By adjusting the power output according to the corresponding wavelength and the distance to the target, and quickly switching between the wavelengths of light, a dazzle effect can be obtained with an irradiance within a safety range for the eye.

The invention provides an external cavity semiconductor laser with multi-wavelength combination. The external cavity semiconductor laser comprises a plurality of semiconductor laser units, alignment optical lenses arranged in order on output optical paths of the semiconductor laser units, dispersion optical elements, and partial reflectors. The plurality of semiconductor laser units are in a array arrangement, and a plurality of resonant external cavities are formed by each semiconductor laser unit, the dispersion optical element, and the partial reflector. In the formed structure of the external cavity, the each semiconductor laser unit automatically adjusts the output wave of the semiconductor laser unit, so that a multi-wavelength light beam finally output by the partial reflector is a parallel and single laser with multi wavelengths. According to the external cavity semiconductor laser with multi-wavelength combination provided in the invention, an effective multi-wavelength laser light source is provided; an actual lasing wavelength of each die are stabilized automatically to be a wavelength that is needed to make the system work cooperatively.

A manufacturing method of a multi-wavelength laser array chip includes the steps of firstly, sequentially growing a buffer layer, a lower separate confinement layer and a multiple quantum well layer on a substrate; secondly, corroding part of the multiple quantum well layer, and using the corroded part as a passive optical combiner area and the rest part as an active area; thirdly, manufacturing medium mask pairs on the remained multiple quantum well layer; fourthly epitaxially growing an upper separate confinement layer on the upper surface of each of the passive optical combiner area and the active area; fifthly, removing the exposed medium mask pairs, and manufacturing gratings on the upper separate confinement layer on the active area; sixthly, extending a wrapping layer and a contact layer on each upper separate confinement layer; seventhly, etching an active waveguide on the contact layer of the active area, and etching a passive optical combiner waveguide on the contact layer of the passive optical combiner area; eighthly, manufacturing P electrodes on the active waveguide; ninthly, thinning the substrate, and manufacturing N electrodes at the back of the thinned substrate.

The invention provides an optically controlled phased array radar front end transmitting and receiving method and a device. The device is based on wavelength division multiplexing, radar radio frequency signals are loaded onto multi-wavelength optical signals when signals are transmitted, and the signals are inputted to an optical delay network; then, the signals are converted into phase-shift electric signals via an optical wavelength division demultiplexer and a photoelectric converter, and the electric signals are transmitted via a microwave antenna array; and when the signals are received, the received electric signals are loaded onto a multi-wavelength optical carrier, and the optical signals are converted into phase-compensation electric signals via a photoelectric conversion array for subsequent processing after passing through the wavelength division multiplexing optical delay network. An optical switch and an electrical switch are used to carry out time division multiplexing on a multi-wavelength laser source, the wavelength division multiplexing optical delay network, the photoelectric conversion array and other devices and structures in the case of transmitting and receiving of the optically controlled phased array radar, repeated use of key devices can be fully realized, the optically controlled phased array radar transmitting and receiving structure is simple and compact, and the cost of the optically controlled phased array radar is reduced.

The invention discloses a multi-wavelength light source-based Brillouin optical time domain reflectometer which comprises a multi-wavelength laser, a coupler, an electrooptical modulator, an erbium-doped optical fiber amplifier, an optical filter, a circulator, a double-balanced detector and a signal acquiring and processing system, wherein continuous light of the multi-wavelength laser is divided into two paths, wherein one path is modulated into pulse light through the electrooptical modulator and the other path is modulated to obtain continuous light of a local oscillator through an electrooptical modulator sideband. Multi-wavelength detection pulse light is amplified by the erbium-doped optical fiber amplifier, subjected to spontaneous emission noise filtration by the optical filter and is injected into a sensing optical fiber by the circulator. Stokes Brillouin back scattering light in the sensing optical fiber is coherent with local oscillator light through the circulator, is subjected to photovoltaic conversion through the double-balanced detector and then is fed into the signal acquiring and processing system to obtain a Brillouin scattering spectrum on the whole optical fiber and further obtain the temperature and strain distribution on the optical fiber.

The present invention is a tunable semiconductor laser for swept source optical coherence tomography, comprising a semiconductor substrate; a waveguide on top of said substrate with multiple sections of different band gap engineered multiple quantum wells (MQWs); a multiple of distributed feedback (DFB) gratings corresponding to each said band gap engineered MWQs, each DFB having a different Bragg grating period; and anti-reflection (AR) coating deposited on at least the laser emission facet of the laser to suppress the resonance of Fabry-Perot cavity modes. Each DFB MQWs section can be activated and tuned to lase across a fraction of the overall bandwidth as is achievable for a single DFB laser and all sections can be sequentially activated and tuned so as to collectively cover a broad bandwidth, or simultaneously activated and tuned to enable a tunable multi-wavelength laser. The laser hence can emit either a single lasing wavelength or a multiple of lasing wavelengths and is very suitable for swept-source OCT applications.

A seed light source for use in Wavelength Division Multiplexed Passive Optical Network (WDM-PON) includes a multi-channel quantum dot laser for generating a multi-channel seed light comprising a plurality of respective channel seed lights. Each channel seed light corresponds to a respective channel of the WDM-PON.

A superbroadband or multiwavelength laser transmitter source for wavelength-division multiplexing, two-wavelength interferometry, differential lidar and optical storage applications. Contrary to conventional tunable laser sources that can switch between different lasing wavelengths in a given wavelength band, the superbroadband laser simultaneously emits at multiple wavelengths. The basic idea of this system is to maintain simultaneous lasing operation in an optical active gain medium at different wavelengths. The system uses a novel dispersive cavity. By designing this cavity structure appropriately, the system creates its own microcavities each lasing at a different wavelength within the fluorescence band of the gain medium. Mode competition in the proposed cavity is absent and spectral range of simultaneous multi-frequency generation is considerably enhanced practically to the spectral width of the active media luminescence spectrum. As a result, the radiation of each mode with its own wavelength is amplified in the active media independently from the simultaneous amplification of the rest of the wavelengths.

An all-fiber device platform for producing high-power ROGB or RGB laser output comprises an optical fiber including multiple waveguide gain regions embedded within a common inner cladding and within an outer cladding, an optical cavity defined by dielectric reflectors and / or FBG mirrors, and a pump source for exciting one or more active ionic species by one or multiple pump wavelengths from one or both ends of the optical fiber through upconversion process. An apparatus for producing sequential or simultaneous multiple wavelength laser operation provides for applications of color projection displays and biomedical or other instrumentation.

The invention, which belongs to the photoelectric imaging technology field, relates to a multispectral stripe tube three-dimensional lidar imaging apparatus. The apparatus comprises: a multi-wavelength laser, a beam expanding prism, a reception telescope, a diffraction grating spectroscope, a convex lens, optical filters, a stripe tube, a coupling light cone, and a CCD camera. A mixing multi-wavelength laser beam that is emitted by the multi-wavelength laser passes through the beam expanding prism and then is shot at an object and is reflected; the reflected laser beam is received by the reception telescope and is gathered to the diffraction grating spectroscope; and then the gathered laser beam passes through the convex lens and is focused on the optical filters; the focused laser beam bombards a photoelectric cathode of the stripe tube to generate a plurality of electron beams though a slit and the plurality of electron beams bombard a fluorescent screen in the stripe tube; and then a multispectral strip image is coupled through the coupling light cone and is imaged on the CCD camera. According to the invention, a multi-spectral detection technology is integrated into a stripe tube lidar imaging apparatus, so that accuracy of object imaging and richness of information are improved; and a specific wavelength can detect a weak signal; therefore, an application arrange of the stripe tube lidar imaging detection apparatus is expanded.

The invention relates to a phase-polarization multi-freedom-degree-modulation QKD (quantum key distribution) network system and method. The system comprise an Alice transmitting end, a WDM (wavelength division multiplexing) unit and a multi-user Bob end, wherein the Alice end is connected with the multi-user Bob end through the WDM unit, and the Alice end comprises a multi-wavelength laser generating device, an attenuator, a first polarization beam splitter, a first beam combiner, a phase modulator, a first polarization controller and a second polarization controller; the WDM unit comprises a wavelength selecting device; the multi-user Bob end comprises a plurality of unit Bob user ends for receiving different wavebands, and each unit Bob user end comprises a second polarization controller, a third polarization controller, a fourth polarization controller, a third polarization beam splitter, a fourth polarization beam splitter, a second beam combiner, a third beam combiner, a first photon detector, a second photon detector, a third photon detector and a fourth photon detector. The QKD network system has the advantages that one-to-many quantum key sharing, information transmission capacity is expanded effectively, and the system is applicable to a phase-polarization multi-freedom-degree-modulation QKD scheme and other QKD schemes.

The present disclosure is directed to a thermoplastic laser protective eyewear, and methods of manufacturing said thermoplastic laser protective eyewear. In one embodiment, the laser protective eyewear transmits energy in the visible region and absorbs or reflects energy at peak wavelengths that correspond to commercially available industrial, military and medical lasers.

In a Wavelength Division Multiplexed Passive Optical Network (WDM-PON) including, a system for overlaying an analog broadcast signal. An Optical Line Terminal of the WDM-PON includes a broadband light source for generating uplink seed light for each uplink channel of the WDM-PON, and a modulator for modulating the analog broadcast signal onto the uplink seed light. An Optical Network Terminal of the WDM-PON receives the uplink seed light from the Optical Line Terminal, and includes an optical divider for dividing the received seed light into a first signal and a second signal; a light source for generating an uplink data signals using the first signal as seed light; and an RF receiver for detecting the analog broadcast signal modulated on the second signal.

The invention discloses a loss analysis device of a passive device, comprising a multi-wavelength light source, an optical switch, a polarization controller (PC), a shunt, a return loss test module, an optical power meter module and a singlechip, wherein the multi-wavelength light source is used for providing multi-wavelength lasers with stable power; the optical switch is used for selecting one of the multi-wavelength lasers for output; the PC is used for changing the polarization state of the lasers; the shunt is provided with a first end, a second end and a third end; the return loss test module is used for testing optical power reflected by the input end of the passive device to be tested; the optical power meter module is used for testing the optical power of the output end of the passive device; and the singlechip is used for controlling the laser output of the multi-wavelength light source, the laser selection of the optical switch and the changes of the PC for the laser polarization state, receiving data tested by the return loss test module and the optical power meter module, and processing the data. The loss analysis device is a multifunctional device which integrates the functions of a stable distributed feedback (DFB) light source, the optical power meter module, a plugging-return loss test set, and a polarization dependent loss (DPL) tester into a whole.

The invention discloses a vibration-rotational Raman-Mie scattering multi-wavelength laser radar system and a working method thereof. The system comprises a first system and a second system, wherein the first system works in an ultraviolet wave segment, the second system works in a visible infrared wave segment, and the first system and the second system both comprise laser emission units, optical receiving units, signal detection and data collecting units and control units. The laser emission units are used for emitting lasers to air, the optical receiving units are used for receiving back scattering echo signals of the air on the lasers emitted by the laser emission units, and conduct rotational Raman, vibration Raman and elastic scattering light splitting on the back scattering echo signals, the signal detection and data collecting units are used for obtaining parameter information of air temperature, water vapor, aerosol and cloud from the back scattering echo signals after light splitting, and the control units are used for controlling the laser emission units, the optical receiving units and the signal detection and data collecting units to run. The vibration-rotational Raman-Mie scattering multi-wavelength laser radar system and the working method of the system can achieve all-weather air comprehensive continuous automatic observation.