57results about How to "Wavelength tunable" patented technology

The invention relates to a cascade long-period pohotonic crystal fiber grating temperature sensor. A photonic crystal fiber is provided with a cladding consisting of periodically arrayed air holes; the cladding and a fiber core of the fiber are made of SiO2; a long-period grating with a certain period is written onto the fiber; the air holes of the cladding are filled with thermosensitive substances sensitive to temperature; the refractive indexes of the thermosensitive substances are less than the refractive index of the fiber core; and the total internal reflection photonic crystal fiber is formed. The effective refractive index of a coupled mode of the grating can be changed by controlling the temperatures of the thermosensitive substances, so that the resonant wavelength of a transmission spectrum of the grating is changed, the temperature variation is shown as spectral shift, and the wavelength-tunable temperature sensor is realized. As the bandwidth of the transmission spectrum of the single long-period grating is greater, the temperature sensitivity and the measurement precision of the transmission spectrum of the long-period grating are limited, and the sensor is transformed into a cascade long-period grating structure. The sensor achieves the tunable wavelength, the sensitivity is improved, and the sensor has a very large application prospect in the transduction field.

The invention discloses a random fiber laser system with tunable wavelength, belonging to the laser device field. According to the system, first pump source laser with tunable wavelength and a series of low energy seed source laser are injected into a fiber, through a series of Raman amplification effects, distributed Raman amplification light is generated in a transmission fiber, and distributedRayleigh backward diffusion light forms random laser after Raman amplification. A random laser in the invention can realize continuous tunable wavelength. In a selectable scheme, after first Raman amplification, residual energy of a first pump source or a first seed source is fed back to the fiber for reuse, and slope efficiency of a finally formed random laser is raised. The system can control aRaman gain and a shape of a Raman gain spectrum through additional seed light, reduce a threshold of the laser, and raise output power.

The invention relates to a single longitudinal mode distributed feedback optical fibre laser with tunable wavelength. Ultraviolet silica gel for phase shift optical fibre grating is fixed at the bottom of a V-shaped aluminum groove which is affixed on a heat sink plate by using heat conducting silica gel; the heat sink plate is tightly arranged on a semiconductor refrigerating plate through heat conducting materials; the lower surface of the semiconductor refrigerating plate is in close contact with the radiating plate through a layer of heat conducting materials; the positive and negative ends of the semiconductor refrigerating plate are connected to a linear power supply through a lead; one end of the phase shift optical fibre grating is connected with a combiner port of a 980/1030 wavelength division multiplexer; a port 980 of the wavelength division multiplexer is connected with a tail fibre of the semiconductor laser; a port 1030 of the wavelength division multiplexer is connected with an optical fibre jumper head of a slope; the other end of the phase shift optical fibre grating is connected with an optical fibre isolator; and the contact surfaceof the heat sink plate and air and the contact surface of the V-shaped aluminum groove and air are all covered by heat insulation cotton. The laser has the characteristics of tunable wavelength, stable output of single longitudinal mode and miniaturization.

The invention discloses a narrow-linewidth mode-locking thulium-doped fiber laser with a high repetition rate, which belongs to the technical field of fiber lasers. In order to improve the repetitionrate outputted by the passive mode-locking thulium-doped fiber laser, a pumped laser is connected with an erbium ytterbium co-doped fiber amplifier; the erbium ytterbium co-doped fiber amplifier is connected with a wavelength division multiplexer, and the wavelength division multiplexer is connected with a thulium-doped fiber; the thulium-doped fiber is connected with an isolator, and the isolatoris connected with a filter; the filter is connected with an output coupler, and output light is outputted through the output coupler; the output coupler is connected with a single-mode fiber, the single-mode fiber is connected with a second polarization controller, the second polarization controller is connected with a polarizer, the polarizer is connected with a first polarization controller, and the first polarization controller, the polarizer and the second polarization controller are used as mode-locking elements to realize nonlinear deflection effect passive mode-locking; and the first polarization controller is connected with the wavelength division multiplexer to form a ring cavity. The narrow-linewidth mode-locking thulium-doped fiber laser with a high repetition rate is applicable to fields of optical communication, spectroscopy, precision optical sampling and other technologies.

The invention discloses a solid-state laser with a dual-composite-resonant-cavity structure and tunable wavelength. The laser enables unpolarized 1064.2nm simulated radiation fluorescence generated by Nd:YAG crystals to pass through a first resonant cavity and a second resonant cavity to realize s-polarized 1064.2nm pumped laser and p-polarized 1064.2nm fundamental frequency light oscillation respectively; the s-polarized 1064.2nm pumped laser pumps a third resonant cavity to generate s-polarized signal light with tunable wavelength and middle-infrared band s-polarized idler frequency light; and the s-polarized signal light with tunable wavelength and the p-polarized 1064.2nm fundamental frequency light perform sum-frequency mixing to form s-polarized sum-frequency laser with tunable orange red band wavelength. By adoption of the laser disclosed by the invention, wavelength-turnable and high-power laser output at the orange red band and the middle-infrared band can be realized at the same time; and the laser is compact in structure, high in energy conversion efficiency, and can be widely applied to the fields of biomedicine, laser measurement, pollution monitoring, spectral analysis and the like.

The invention discloses a semiconductor laser, which comprises a semiconductor PN junction, and a surface active Bragg reflection grating, a ridge-shaped waveguide array, a multimode interference waveguide and a super-symmetric array waveguide which are arranged on the semiconductor PN junction and distributed along the same column, the surface active Bragg reflection grating is arranged at one end of the ridge-shaped waveguide array, one end of the multimode interference waveguide is adjacent to the other end of the ridge-shaped waveguide array, and the super-symmetric array waveguide is adjacent to the other end of the multimode interference waveguide. According to the semiconductor laser, the surface active Bragg grating is used for providing single-frequency laser with tunable wavelength, the ridge-shaped waveguide array is used for gain amplification, the multimode interference waveguide is used for coherent coupling, and finally, the super-symmetric array waveguide is used for secondary transverse mode selection and gain. And high-power, narrow-linewidth and wavelength-tunable high-beam-quality laser is realized.

The invention discloses a feedback enhancement type polarization-maintaining erbium-doped fiber dual-wavelength random laser. The laser comprises a pump laser light source, an optical fiber wavelengthdivision multiplexer, a first optical fiber polarization controller, a first optical fiber polarization beam combiner, a polarization-maintaining erbium-doped optical fiber, a second optical fiber polarization beam combiner, an optical fiber laser, a first optical fiber coupler, a second optical fiber polarization controller, a first optical fiber isolator, a third optical fiber polarization controller, an electro-optical modulator, an arbitrary waveform generator, a fourth optical fiber polarization controller, a second optical fiber isolator, a second optical fiber coupler and the like. According to the random laser, a random Brillouin dynamic grating is generated in one axis of the polarization-maintaining erbium-doped optical fiber, and pumping is carried out in the other axis of thepolarization-maintaining erbium-doped optical fiber. The random Brillouin dynamic grating enhances the random feedback of the polarization maintaining optical fiber, so that random laser output is generated on the two axes of the polarization maintaining optical fiber, and the random laser has the advantages of the high integration level, the low threshold value and high conversion efficiency.

The invention relates to a device for generating wavelength-tunable ultra-short visible and near-infrared laser pulses simultaneously. The device comprises a femto second laser, a tunable secondary non-linear optical parameter amplification system, a chirp mirror-prism pair compression system and a super-continuous near-infrared white light generation system, a light beam output by the femto second laser is divided into two light beams by the tunable secondary non-linear optical parameter amplification system, one light beam is amplified and enters the chirp mirror-prism pair compression system, and the other light beam directly enters the super-continuous near-infrared white light generation system. According to the device, wavelength-tunable visible laser pulses of high light beam quality and periodic quantity level as well as near-infrared ultra-short laser pulses of the high light beam quality can be obtained simultaneously.

The invention relates to the field of lasers, in particular to a dual-frequency laser. In a tunable dual-frequency laser, a first pump beam and a second pump beam with the same power and polarization direction are incident into a microchip laser cavity at spatial intervals; and the microchip laser cavity at least comprises a front cavity lens, a laser gain dielectric slab, an etalon of an air gap, and a rear cavity lens which are sequentially glued, wherein the etalon of the air gap is formed by fixing the laser gain dielectric slab and the rear cavity lens by using two etalon supports at an interval, and a first optical plain film and a second optical plain film with the same thickness or almost same thickness are respectively inserted into a first optical path and a second optical path of the first pump beam and the second pump beam in the gap to respectively adjust the output wavelength of the laser. Therefore, in the dual-frequency laser wavelengths are tunable, and the laser is stable in working and has a small size.

The present invention provides a delay feature inhibition chaotic signal generation device. The device comprises a delay feature inhibition chaotic signal generation module and a collection and analysis module; optical signals, output from a WRC-FPLD, of the delay feature inhibition chaotic signal generation module are divided into two branches through an optical fiber coupler, the two branches are finally combined and input into the optical fiber coupler to form two filtering external cavity feedback loops, and the central wavelengths of adjustable filters in the two external cavities are regulated to allow the laser to output chaotic signals with different wavelengths; the cavity lengths of the two external cavity feedback loops are regulated to allow the difference of the cavity lengthsto be equal to half of the laser relaxation vibration time so as to achieve output of delay feature inhibition chaotic signals with tuning wavelengths; and the collection and analysis module collectsthe output signals of the chaotic signal generation module to regulate the working temperature and the working current of the WRC-FPLD. The delay feature inhibition chaotic signal generation device employs the WRC-FPLD as a laser source to achieve output of chaotic signals with different wavelengths so as to facilitate application in the WDM communication system.

A broadband wavelength tunable mid-infrared Raman fiber laser includes a tunable fiber laser unit, a fiber amplifier unit, a collimating coupling unit and a Raman laser resonator unit, the Raman laserresonator unit includes a grating, the tunable fiber laser unit outputs laser light of a preset first band to the fiber amplifier unit, and after the laser light of the first wave band passes throughthe optical fiber amplifier unit to amplify the optical power, the laser light is input tothe collimating coupling unit; the collimating coupling unit couples the laser light after the optical poweramplification to the Raman laser resonator unit. The Raman laser resonator unit outputs the Raman laser light with the preset second wavelength band by adjusting the tilt angle of the grating based onthe laser light after the optical power amplification. As a grating exists in the Raman laser resonator unit, the wavelength of the Raman laser output can be adjusted by adjusting the tilt angle ofthe grating, so that the application field of the laser can be greatly expanded.

The invention provides a filter drive circuit of a swept source. The filter drive circuit of the swept source comprises a signal generating circuit, a filter circuit, a gain adjusting circuit and a filter load, wherein the signal generating circuit is used for generating sine wave signals, an input end of the filter circuit is connected with an output end of the signal generating circuit, the filter circuit is used for filtering noise beyond a sine wave signal band, an input end of the gain adjusting circuit is connected with an output end of the filter circuit, an output end of the gain adjusting circuit is connected with the filter load, and the gain adjusting circuit is used for amplifying the mixed wave form of the sine wave signals and narrow band noise. According to the filter drive circuit of the swept source, output frequency of the swept source can be continuously adjustable between 20 KHz and 200 KHz, peak-to-peak value voltage can be 3 V, phase is adjustable, and output load is about 1 omega. Filter load stability is guaranteed, the requirements on modulation amplitude of different laser devices are met, and sweep frequency laser wavelength can be coordinated.

The invention provides a wavelength-adjustable all-fiber nanosecond pulse laser device based on a photonic crystal fiber and a system. The laser device comprises a pump light input unit, an isolator,a wavelength tuning unit, a high-nonlinearity optical fiber and a laser output unit which are sequentially connected through optical fibers, wherein the pump light input unit is connected with the laser output unit through the optical fiber, the pump light input unit is further connected with an external pump light source and is used for obtaining the pump light, coupling the pump light and then obtaining signal light, the isolator is used for ensuring laser operation unidirectionality, the wavelength tuning unit comprises a first polarization controller, a photonic crystal fiber and a secondpolarization controller which are sequentially connected through the optical fibers, the high-nonlinearity optical fiber is used for improving nonlinearity and dispersion of the signal light, and thelaser output unit is used for obtaining and outputting ultrafast pulse laser based on the signal light. The laser device is simple in structure, small in size and suitable for various application occasions such as communication.

The invention discloses a multi-wavelength ring laser chip which comprises a chip substrate, a chip lower wrapping layer, a passive waveguide core layer and an active waveguide core layer. A periodic wavelength selection function of the array waveguide grating is utilized, the array waveguide grating, a plurality of active waveguide amplifiers and a tunable filter are subjected to monolithic integration, so that a corresponding multi-wavelength and wavelength-tunable light source is obtained, and the scheme can generate stable and synchronous multi-wavelength oscillation under the condition of no complex wavelength control; the multi-wavelength laser chip not only meets the wavelength requirement of a wavelength division multiplexing communication band, but also has the greater advantages of being high in integration level, small in size, tunable in wavelength, and high in reliability and environmental adaptability.