134results about How to "Wavelength stable" patented technology

A vertical cavity surface-emitting laser (VCSEL) package useful in interferometry. The present invention comprises methods and apparatuses that allow use of multimode VCSELS, and that provide for wavelength control and stability. The present invention contemplates the use of a defined response element, such as an etalon, in combination with control of the operating environment of the VCSEL to monitor and control the output wavelength of the VCSEL.

The invention relates to an on-line optical fiber grating preparing system, which comprises a wire drawing tower and a grating inscribing device, wherein the wire drawing tower comprises a wire drawing furnace and a prefabricated bar clamping feeding device arranged above the wire drawing furnace, a naked optical fiber diameter gauge is arranged under a furnace opening of the wire drawing furnace, the grating inscribing device is arranged under the naked optical fiber diameter gauge, an optical fiber coating curing device is arranged under the grating inscribing device along the vertical downward direction of the naked optical fiber, and a wire drawing take-up mechanism is arranged under the optical fiber coating curing device. The on-line optical fiber grating preparing system is characterized in that the grating inscribing device comprises a phase mask plate and a 193nm excimer laser, wherein the phase mask plate is arranged in a way of being next to the center of the naked optical fiber, the output end of the 193nm excimer laser is alternately provided with a diaphragm and a lens, the 193nm excimer laser outputs single-pulse laser beams, and the single-pulse laser beams are illuminated onto the phase mask plate through diaphragm shaping and lens focusing. The on-line optical fiber grating preparing system has the advantages that the arrangement is reasonable, the performance is stable, the manufacturing efficiency is high, in addition, the precision of the manufactured grating is high, the grating spectral form is good, and the consistency is high.

The invention provides an optical frequency comb generation device with the comb tooth frequency interval capable of being scanned. A signal generator form two output ends through a microwave power distributor, wherein the first output end is connected with a photoelectric phase modulator after passing through a first broadband microwave power amplifier, the second output end is connected with a photoelectric intensity modulator after sequentially passing through an adjustable microwave delay line and a second broadband microwave power amplifier, a continuous wave laser carries out output sequentially through the photoelectric phase modulator and the photoelectric intensity modulator , the photoelectric phase modulator and the photoelectric intensity modulator are cascaded, and the photoelectric intensity modulator has direct-current bias. The invention further provides an optical frequency comb generation method. According to the optical frequency comb generation device and method, broadband continuous frequency scanning and accurate arbitrary adjustment of the comb tooth frequency interval are achieved, a generated optical frequency comb is stable in phase, frequency and central wavelength, and tunable, the device is simple in scheme, and low in cost, and the optical frequency comb generation device and method meet the requirement for application in the fields such as the optical measurement field, the laser radar field, the laser spectroscopy field, the optical fiber sensing field, the optical communication field and the microwave photonics field.

The invention relates to a tunable erbium-doped fiber ring laser which can output stable wavelength and power, which relates to an optical fiber communication technology. The tunable laser and an isolator of the invention are connected with the ring cavity through an input terminal of a first optical coupler, the 980nm pumping is optically coupled in the erbium-doped fiber gain medium by a WDM coupler; a second optical coupler is an output terminal; through controlling phase-shift phase of phase-shifted grating, filtering function can be realized; through regulating the wavelength of the injected laser of the tunable laser, injection locking can be realized and the laser can be stably outputted. The tunable single-longitudinal erbium-doped fiber ring laser of the invention has the advantages of low cost, simple device and easy operation; the tunable single-longitudinal mode output with output wavelength and wavelength of stable power can be finally obtained.

The invention relates to a Raman spectra measuring device for multi-wavelength laser frequency shift excitation. The Raman spectra measuring device comprises at least two semiconductor lasers used for generating lasers with fixed wavelengths, at least two laser control modules used for controlling parameters of the lasers, a fiber-optical switch used for switching light sources of the semiconductor lasers, a Raman probe used for carrying out focusing excitation on a sample to be detected and collecting Raman optical signals generated by the sample, a sample cell used for placing the sample to be detected, a grating splitting module used for dividing the Raman optical signals on space, a spectral data acquisition module used for carrying out photoelectric conversion on the Raman optical signals and an arithmetic processing module used for analyzing and extracting Raman spectra. The Raman spectra measuring device is capable of overcoming the disadvantages of the common tunable laser of instability, complex device or the like, effectively inhibiting fluorescence interference and realizing Raman spectra detection under strong fluorescence background.

The invention discloses a 10 Giga optical link terminal optical transmitter and receiver integrated module, which includes a module optical interface, a module electrical interface and a kilo mega transmitter and receiver integrated optical component, also includes a 10 Giga optical transmitter component, and a 10 Giga transmitter drive circuit for driving the component. The 10 Giga transmitter drive circuit is composed of a signal transformation circuit, a laser drive circuit and a matching circuit, wherein the signal transformation circuit input terminal is connected with the electrical signal to be transmitted, the signal after being transformed by the signal transformation circuit is inputted into the laser drive circuit, the modulated signal, which is outputted from the laser drive circuit and is modulated by the matching circuit, is inputted into the electroabsorption modulator input terminal of the 10 Giga optical transmitter component, for driving 10 Giga optical transmitter component transmitter emitted light signal. The optical receiver and transmitter integrated module has signals with 10Gbps and 1.25Gbps down transmission rate, and signals with 1.25Gbps upward transmission rate, thereby realizing asymmetric transmission of upward signal and down signal for meeting the need of high-speed bandwidth.

The invention discloses a thermal radiation infrared transmitting and probing integrated device. The integrated device is in the structure that: a silicon substrate provided with a substrate insulation layer is opened with at least one thermal isolation cavity, the thermal isolation cavity is suspended with at least one transmitting unit and at least one probing unit which are adjacent and are arranged side by side, the transmitting unit is connected with the silicon substrate by virtue of at least two supporting arms, and the probing unit is connected with the silicon substrate by virtue of at least two supporting arms. The transmitting unit comprises a first insulation layer, a non metal conductive layer, a first medium layer and a first surface conductive layer which are superposed from the bottom to the top; and the probing unit comprises a second insulation layer, a metal conductive layer, an isolation layer, an infrared sensitive layer and a photonic crystal microstructure layer which are superposed from the bottom to the top. The integrated device has the advantages of simple structure, stable high temperature properties and adjustable wavelength, and narrow-band absorption probing narrower than the width of wavelength spectrum of the transmitting unit can be obtained. The integrated device of the invention can be applied to infrared gas sensor and infrared spectrometer.

An embodiment of the present invention provides an optical module and an optical signal output control method thereof. The optical module comprises a distributed Bragg reflective DBR laser, a driving circuit for supplying a driving current to the active region of the laser, a first current source, a second current source, and a circuit switching unit. The first and second current sources are used for outputting a first current and a second current. The two input ends of the circuit switching unit are respectively connected to the current output ends of the first and second current sources. The output end of the circuit switching unit is connected to the DBR area of the laser. The circuit switching unit is used for connecting the current output end of the first current source to the DBR area of the laser to output the first current to allow the laser to transmit an optical signal with operating wavelength, after an optical transmitting signal is received. The circuit switching unit is further used for connecting the DBR current output end of the second current source to the DBR area of the laser to output the second current to allow the laser to transmit an optical signal with non-operating wavelength, after an optical stopping signal is received. The optical module is operated in a burst mode and wavelength shift of the optical signal emitted by the laser is small.

A method for stabilizing light wavelength of multi-channel includes generating the first detection signal with band different to multipath driving signal, superposing the first detection signal on multipath driving signal in sequence to obtain multipath light signal and a path of light general signal, carrying out wavelength detection on light general signal, picking up the second detection signal with band as the same with the first one in sequence from wavelength detection result and controlling light wavelength of relevant channel on multi-channel emitter as per obtained second detection signal.

The invention discloses a method of compensating fiber grating temperature coefficient with encapsulation cannula which possesses negative temperature coefficient. A material which does not possess negative temperature coefficient is used to produce encapsulation cannula with tiny negative heat expansion coefficient by special process; it can completely compensate the wavelength shift generated by change of temperature. The encapsulation cannula encapsulates the fiber grating quickly under the high temperature to produce fiber grating which is not sensitive to temperature and possesses high heat stability, and it is high and low temperature circle aged for multiple times. The invention is simple, cost is low, more important is that the temperature performance is well, the temperature coefficient of fiber grating can achieve 0.0005nm/DEG C under the circumstance of -10DEG C to 60DEG C, and it possesses perfect long time temperature property. The column of the fiber grating encapsulated is small, the weight is light, shock resistance property is strong, and it is an ideal encapsulation method for fiber grating.

The invention discloses a fiber laser single-wave self-mixing interference displacement measuring system, and belongs to the technical field of optical measuring. The system comprises a pumping source, a laser device, five optical fiber gratings, three optical fiber isolators, two detectors, an Er-doped fiber, piezoelectric ceramic, a 3dB coupler, a circulator, a collimating mirror, a wavelength division multiplexer, a variable optical attenuator, a signal processing circuit, a feedback control circuit, an A/D (analog to digital) conversion card, a computer and result output. A pair of optical fiber gratings with the same reflection wavelength is used as a laser resonator mirror to generate single-wavelength laser; the single-wavelength laser is projected to a measured object surface, reflected or scattered back to a laser cavity through a measured object to generate self-mixing interference with light in the cavity, so that displacement measuring with nano-scale resolution is realized. The system can measure a low-reflectivity object due to an amplifying effect of a gain medium in the laser cavity; output wavelength of the laser device is stabilized through feedback control, so that the measuring precision is greatly improved; the fiber laser device is not only a sensor, but also an interferometer, is simple in structure and easy to carry.

The invention, which relates to the fiber optic communication field, discloses a long-distance small from-factor pluggable plus (SFP+) optical module. And the invention aims at providing a long-distance SFP+ optical module with low power, wherein the SFP+ optical module enables an internal temperature of the optical module to be reduced. Technical notes of the invention are as follows: an electroabsorption-modulated-laser (EML) laser and driver is employed on an original SFP+ optical module; and a thermoelectric refrigerating unit, an avalanche photo diode (APD) high voltage control unit, and a corresponding temperature collection circuit and a DA converter are added; and a controller unit is used for controlling and monitoring a laser driving unit, a limiting amplifier, the thermoelectric refrigerating unit and the APD high voltage control unit. The controller unit controls the thermoelectric refrigerating unit and the APD high voltage control unit respectively according to temperatures of an optical sending interface assembly and an optical receiving interface assembly, so that a working temperature of a laser in the optical sending interface assembly is stable, thereby outputting am optical signal with a stable wavelength; besides, according to a working temperature of the optical receiving interface assembly, compensation is carried out on a reversed breakdown voltage of the APD, thereby improving a reception sensitivity.

Infrared laser light generated by a solid state diode pumped transform-limited Ti:Sapphire laser is converted to UV wavelengths using third and fourth harmonic generation systems. The resulting output is tunable between approximately 187 and 333 nm. The combined solid state Ti:Saapphire laser and harmonic generation system includes feedback mechanisms for improved power and wavelength stability. The system can operate at pulse repetition rates of several thousand Hertz.

A pad for thermotherapy includes: a stretchable and flexible substrate; an electrode pattern positioned over the stretchable and flexible substrate, and including a plurality of light source electrodes and a linear electrode connecting the light source electrodes; light sources positioned over the electrode pattern; and a power supply unit for supplying power to the light source, wherein the linear electrode is formed longer than intervals between neighboring light source electrodes and separated from the substrate.

The invention discloses a method for detecting adhesion between spatial heterodyne interferometer gratings, which relates to the field of optical instruments. The method comprises the steps that: a heterodyne interferometer to be adhered is vertically placed on a transparent platform of an adhesion regulation mechanism; laser lights output by a laser are subjected to diffuse reflection of an integrating sphere to form a uniform surface light source and are incident to an alignment system to form parallel lights which are incident on the heterodyne interferometer to be adhered; interference fringes are formed on an exit end of the heterodyne interferometer to be adhered, wherein the interference fringes are received by a CCD after passing through an image system and are displayed on a computer in real time; fx interference fringes formed on the whole image surface width w1 of the CCD by a special wavelength light source lambda 0 after the special wavelength light source lambda 0 passes through an interference system are calculated; a photosensitive adhesive is uniformly coated on the heterodyne interferometer to be adhered, micro-adjustment is performed on oblique angles of alpha and beta of two arm gratings, and the interference fringes on the whole image surface of the CCD are read till f changes to fx to enable the two gratings to be positioned; and two adhered gratings are cured. The method for detecting adhesion between the spatial heterodyne interferometer gratings solves the technical problem of difficult accurate control over the grating oblique angle in the adhesion process of the spatial heterodyne interferometer. The error of the oblique angels of the two arm gratings can be controlled in 2.5 seconds.

The multiple wavelength ultra continuous light source of dense wavelength division multiplexing belongs to optical communication area. Two fiber-coupler forms loop type cavity. Continuous light output from semiconductor laser through connection of 50:50 fiber coupler is input to phase modulator. Connection sequence is as following: from radio frequency microwave source to phase modulator, dispersed fiber, powerful erbium doping amplifier, dispersion displacement optical fiber, 90:10 fiber coupler. 90% output port is connected to another input port of 50:50 fiber couplers. 10% port is connected to one end of erbium doping fiber amplifier, and another end of the erbium doping fiber amplifier is input to demultiplexer. The invention through modulation generates stable shorter light wavelength with lower injected optical power.

The invention relates to a multipoint gas sensing system based on an optical fiber buffer, which comprises an address encoder, a double-wavelength light source, a multipoint optical fiber sensing network and a demodulator. The address encoder generates an address code and a read-write control signal of different monitoring points; each detecting unit of the multipoint optical fiber sensing network adopts a buffer structure introduced with a gas absorbing chamber in an optical fiber loop; a double-loop coupling all-optical buffer and a polarization type all-optical buffer can be adopted; under the control of a write signal, the optical signal of the address code is written into the optical fiber loop of the detecting unit and circularly absorbed by the gas many times; the absorbed optical signal is read out and sent to the demodulator for photoelectric conversion, comparison with the reference light, address decoding and data processing in order to gain the gas concentration in different points and realize the multipoint gas monitoring. The system gains the good effects through improving the structure of the absorbing chamber, adding an optical amplifier, a polarization control and a device with the wavelength of 1665nm, and is used in the monitoring of the gas which has the wavelength of 1665 nm and is near provided with an absorption peak.

The invention belongs to optical communication devices, particularly relates to a laser transmitter, and provides a coaxially-packaged DFB laser transmitter with a refrigeration function. The coaxially-packaged DFB laser transmitter comprises a cavity, a DFB laser chip mounted on a laser chip heat sink and a backlight detection chip mounted on a detection chip heat sink are arranged in the cavity, a TO package structure is adopted, a tube seat, a tube cap, an optical isolator, an adaptor, a lens and a 45-degree total-reflection sheet are coaxially packaged in the cavity, one side of a thermoelectric refrigerating unit is mounted under the laser chip heat sink, and the other side of the same is mounted on the tube seat. The TO coaxial package structure is adopted, the 45-degree total-reflection sheet is adopted to effectively solve the problem of a light path structure, and the thermoelectric refrigerating unit is arranged inside the DFB laser transmitter to accurately control working temperature of the laser transmitter. The coaxially-packaged DFB laser transmitter has the advantages of small size, low cost, stable output wavelength and the like, and high-speed long-distance transmission of laser is realized favorably.

A variable-period permanent-magnet undulator which is applicable not only to a planar undulator but also to a helical undulator, in which permanent-magnets and ferromagnetic substances are alternately arranged, and the ferromagnetic substance interposed between the permanent-magnets is saturated to thus enable the magnets to be effectively spaced apart from each other by the repulsive force between the permanent-magnets, thereby adjusting the period of the magnetic field in an easy and precise manner.

The invention provides a fabrication process of a high-brightness LED. The fabrication process comprises the step of sequentially depositing a buffer layer, an N-type GaN layer, a light-emitting layerand a P-type GaN layer on a substrate by a metal organic chemical vapor deposition process, wherein the substrate is placed on a rotating slide disc, the light-emitting layer comprises a quantum welllayer and a quantum barrier layer which are periodically laminated, at least one of the quantum well layer and the quantum barrier layer which are periodically laminated is a high-speed quantum welllayer and a low-speed quantum well layer, and the rotational speed of the slide disc during forming the high-speed quantum well layer is larger than the rotational speed of the slide disc during forming the low-speed quantum well layer. Indium is doped into gallium nitride by increasing the rotational speed, the indium doping quantity is prevented from being increased by reducing a growth temperature, the quantum well layer is deposited under a higher temperature, and the obtained quantum well layer is better in crystal quality; and meanwhile, the fabrication process is low in cost and is easyto implement.

The invention discloses a manufacturing method and a formula of a graphene far-infrared heating plate. A solution is divided into a main solution, an additive and deionized water. The manufacturing method of the main solution comprises the following steps: putting 20-100g of graphene, 1-10g of stannic chloride (SnCl4), 1-15g of indium trichloride (InCl3) and 1-10g of ammonium fluoride (NH4F) intoa container; and pouring 100-200 mL of absolute ethyl alcohol (EtOH), stirring for 1-3 hours, and standing for 5-30 hours to obtain the main solution. The additive is poured into a main solution container, and the solution is stirred for 10-60 minutes, then 5-30 mL of a hydrochloric acid is added, the solution is stirred for 10-60 minutes, and then the solution stands for 5-15 hours for later use.The hydrochloric acid is added to play a role of a stabilizer, and a far infrared spectrum wavelength of the heating plate is stabilized within the range of 4-14 micrometers by the additive.