196 results about "Single mode laser" patented technology

A large mode area optical fiber includes a large diameter core (d1 up to 60 μm), and a first cladding (diameter d2) wherein the difference between refractive index (n1) in the core and the first cladding (n2) is very small (Δn<0.002), thus providing a very low numerical aperture core (NA1 between 0.02 and 0.06). The preferred ratio of d2 / d1<2. The fiber further has a second cladding, preferably a layer of air holes, having a very low refractive index n3 as compared to the core and first cladding such that the first cladding has a relatively high numerical aperture (NA2>0.4) (n3 is preferably less than 1.3). The small change in refractive index between the core and inner cladding combined with a large change in refractive index between the first cladding and second cladding provides a significantly improved single mode holding waveguide.

In a manufacturing process of a semiconductor device, a manufacturing technique and a manufacturing apparatus of a semiconductor device which simplify a lithography step using a photoresist is provided, so that the manufacturing cost is reduced, and the throughput is improved. An irradiated object, in which a light absorbing layer and an insulating layer are stacked over a substrate, is irradiated with a multi-mode laser beam and a single-mode laser beam so that both the laser beams overlap with each other, and an opening is formed by ablation in part of the irradiated object the irradiation of which is performed so that both the laser beams overlap with each other.

A surface-emitting semiconductor laser (VCSEL) having a structure in which the single horizontal mode of high power is stably maintained, and an optical device including a light-source device having this surface-emitting semiconductor laser are provided. A scattering-loss-structure portion composed of a low refractive-index region is disposed around a main current path in a surface-emitting semiconductor laser, namely around a cavity structure portion; the low refractive-index region is disposed at intervals; and the shape of the tip portion opposing to the center portion is set to be a tapered shape, for example, at an acute angle. Accordingly, in the cavity structure portion, the loss of light-emitting laser of a high-order mode localized in the outer circumferential portion becomes large, so that a surface-emitting semiconductor laser that oscillates the single-mode laser with favorable performance is constructed.

A plurality of image projection modules is operative for causing selected pixels in overlapping raster patterns to be illuminated to produce a large size image of high resolution of VGA quality in monochrome or color. The selected pixels in an overlap region of the patterns are illuminated at a lesser intensity to provide uniform brightness over the image. Multiple single mode lasers, or a multimode laser with an aperture stop, are employed to increase laser output power. Speckle noise is reduced by controlling the optical transmission characteristic of a projection screen. Three-dimensional images are generated by moving the screen. Cross-coupling between drive and feedback mechanisms in image projection is reduced for better image quality.

The present invention relates to a system for generating a two-way light phase modulation millimeter wave and providing remote local oscillator in a millimeter wave optical fiber transmission system and a method thereof. The system comprises a center station and a base station. The center station is composed of a laser, two polarization controllers, a double-electrode Mach-Zehnder modulator, a microwave difference power amplifier, a light intensity modulator, an optical fiber amplifier and the like. The base station is composed of a photodetector, a front low-noise amplifier, a power divider,two band-pass filters, two millimeter wave amplifier and a millimeter wave transmitting antennae. In the method, a single mode laser is divided into two routes at the center station. Two opposite-phase 5GHz cosine microwave signals are used for phase modulating with large modulation index to the two routes of optical wave. The two routes of optical waves are overlapped. The phase variation of theoptical wave is switched to a strength variation through a FM-IM effect. The strength variation comprises a microwave signal and a high order component thereof. The millimeter wave signal is obtainedby extracting the high order harmonic. Then the optical fiber is executed with a strength modulation with a 2GHz BPSK signal and a mode of regulated subcarrier through a light intensity modulator. A 40GHz millimeter wave remote reference local oscillator and a 38GHz BPSK signal are obtained at the base station. The number of optical frequency doubling gets to 8, and the speed of baseband data transmission gets to 200Mbps.

An optically pumped, in particular diode-pumped, continuous solid-state laser produces a primary laser beam whose frequency is converted into the visible or ultraviolet spectral range by means of one or more downstream passive resonators with non-linear crystals. At relatively low cost and complication it is provided that precisely two longitudinal laser modes of approximately equal amplitude are excited in the laser resonator. That achieves a high level of efficiency for the overall system and a very low noise level of the resulting frequency-converted laser beam. In one embodiment of the invention the frequency-converted radiation contains three or more adjacent frequencies. In another embodiment of the invention the frequency-converted laser radiation contains only one single frequency and therefore corresponds to the radiation of a monomode laser.

Wavelength control and stabilization of a laser is achieved by a practical, inexpensive, and accurate technique adapted for most optical transmission system applications by a method involving a laser characterization phase and a laser wavelength control and stabilization phase. This technique is applicable to both single mode lasers and multimode lasers. It is especially useful in those applications where the desired laser output power can vary over a wide range, including relatively low power above the lasing threshold.

A semiconductor laser apparatus includes a silicon-on-insulator assembly and an edge-emitting semiconductor laser assembly integrated on the silicon-on-insulator assembly. The silicon-on-insulator assembly includes an optical waveguide at the top which is bonded to the edge-emitting semiconductor laser assembly and configured to couple a laser light emitted from the edge-emitting semiconductor laser assembly, and the optical waveguide includes a core portion located in the middle of the optical waveguide; and at least one vertical rib configured on two sides of the core portion respectively, with a width narrower than that of the core portion. The apparatus obtains a single mode laser operation and has low propagation loss and high mechanical bond strength.

The invention relates to a preparation method of a DFB semiconductor laser capable of working in a wide temperature range, which comprises the steps of sequentially growing a buffer layer, a lower waveguide structure, a lower electron barrier layer, an InGaAsP and AlGaInAs mixed quantum well, an upper electron barrier layer, an upper waveguide structure, a spacer layer, a long-wavelength grating layer and a grating protection layer on an InP substrate so as to complete the preparation of a primary epitaxial wafer; then preparing a uniform grating on the primary epitaxial wafer, and growing thegrating to form a complete epitaxial wafer; and preparing a DFB laser by adopting a conventional ridge waveguide structure process to realize the DFB semiconductor laser working in a wide temperaturerange. According to the invention, the InGaAsP and AlGaInAs mixed quantum well is adopted, the characteristics of high limiting efficiency of an AlGaInAs high-temperature carrier and small temperature drift coefficient of an InGaAsP quantum well gain spectrum are fully utilized to realize single-mode operation of the laser in a wide temperature range, and the long-wavelength grating layer with absorption characteristics is introduced at the same time to increase the absorption of the grating to the FP mode gain, thereby further inhibiting FP oscillation initiation, and realizing the single-mode laser chip capable of working in a wide temperature range.

The invention discloses a frequency-modulation continuous-wave laser distance measuring device of an integrated reference optical-circuit stabilization system. Distance measuring baselines of currentfrequency-modulation continuous-wave laser distance measuring systems are easily influenced by external vibration, and then the distance measuring accuracy is influenced. The frequency-modulation continuous-wave laser distance measuring device of the integrated reference optical-circuit stabilization system includes an external-cavity tunable laser, a measurement interference system, a helium-neonlaser and an auxiliary interference system; the external-cavity tunable laser generates continuous lasers of 1540 nm-1550 nm; the helium-neon laser generates single-mode lasers of 632 nm; the measurement interference system includes a second coupler, a first circulator, a first collimating lens, a first photoelectric detector and a third coupler; a feedback control system for optical-path-difference compensation is arranged in the auxiliary interference system and includes an acousto-optic modulation device, a frequency-modulation signal source, a phase detector, a photoelectric detector, a piezoelectric micro platform, a piezoelectric controller, a servo controller and a plane mirror. The frequency-modulation continuous-wave laser distance measuring device of the integrated reference optical-circuit stabilization system is used for eliminating the influence that the lengths of delay optical fibers change due to the external vibration, and therefore the distance measuring accuracy isimproved.

The invention discloses a hybrid silicon-based whispering gallery mode microcavity laser which adapts to a light source part of a silicon-based photonic integrated circuit. The hybrid silicon-based whispering gallery mode microcavity laser comprises a silicon-based waveguide part and an III-V semiconductor gain part. The III-V semiconductor gain part is formed on the silicon-based waveguide part. The silicon-based waveguide part is in an SOI (silicon-on-insulator) structure with silicon, silicon dioxide and silicon. The silicon-based waveguide part is made into a triangular, rectangular, circular or waveguide-coupled output form to allow for longitudinal mode control. The III-V semiconductor gain part made of gain material is bonded to the SOI structure directly and matches with the SOI structure to form evanescent field coupling output. The hybrid silicon-based whispering gallery mode microcavity laser has the advantages that single-mode output of laser source on a silicon-based semiconductor surface is achieved by a right-triangular, square or round whispering gallery mode microcavity, cavity surface need not be split, large-scale processing is facilitated, optical coupling output and single longitudinal mode operation are easy to implement, and the laser is simpler in process and higher in practicality than the conventional single-mode lasers.

An innovative device and method for providing a laser system utilizing high efficiency diode lasers and optionally the high quality beam characteristics of a crystal gain medium single mode laser by utilizing an optical and mechanical method of forming the beam and directing it to the desired target.

A vertical cavity-surface emitting laser (VCSEL) for emitting a single-mode laser including a multiple transverse mode VCSEL includes a top emitting region, and a dielectric film covering the top emitting region of the multiple transverse mode VCSEL completely, in order to limit the multiple transverse mode VCSEL to emit the single-mode laser.

Embodiments in accordance with the present invention relate to the use of precise etching techniques in the construction of high quality lasers. In accordance with one embodiment of the present invention, Focused Ion Beam Etching (FIBE) of a semiconductor stripe in a multi-mode edge-emitting Fabry-Perot (FP) laser may allow the rapid and effective fabrication of a single mode laser and / or a surface emitting laser. The use of FIBE or other precise etching techniques allows precise control over the dimension, angle, and orientation of etched features, and offers extremely smooth surfaces that reduce optical loss in the resulting device.

The present invention relates to an optical frequency synthesizer and an optical frequency synthesizing method using femtosecond laser optical injection locking, which inject a femtosecond laser optical frequency comb into a diode laser, thus obtaining single-mode laser light, phase-locked to only a single mode in the optical frequency comb, and which change the optical frequency and interval, that is, the repetition rate, of a femtosecond laser, together with the frequency of a semiconductor laser, thus scanning optical frequencies while realizing a single desired optical frequency. The optical frequency synthesizer using femtosecond laser optical injection locking, includes a mode-locked femtosecond laser (110), which is a master laser, and a diode laser (120), which is a slave laser and into which laser light emitted from the femtosecond laser is injected.

The inventive configurable optical fiber polarization mode coupler is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing, and that are preferably optimized for use with photonic integrated circuits, such as coupling to dense optical input / output interfaces, wafer-level testing, etc. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Advantageously, at least one embodiment of the present invention comprises a phase locking optical fiber coupler comprising at least one optical fiber coupler configured as a pitch reducing optical fiber array (PROFA) component configured and optimized coherent combining of multiple optical fiber lasers to produce multi-kilowatt single mode laser sources.

The invention relates to a photoproduction microwave device based on a double-wavelength Brillouin optical fiber laser in the technical field of photoelectricity, comprising a DFB (Distributed Feedback) single-frequency laser, an optical fiber amplifier, an optical fiber circulator, an optical resonant cavity, a cascade resonant cavity, a photoelectrical detector and a frequency spectrograph, wherein the cascade resonant cavity and the optical resonant cavity respectively generate single-module laser with different frequencies. The invention does not need to use an additional microwave signal source to carry out optical frequency stabilization or optical modulation, is in a full-optical fiber light path structure, and has the advantages of simple structure and low cost; and Brillouin laser generated by the two resonant cavities is generated by the same DFB single-frequency laser pumping so that the microwave signals generated by the double-wavelength Brillouin optical fiber laser at a beat frequency have high frequency stability.

The invention discloses a device for generating a photo-induced microwave carrier signal through single sideband modulation. The device comprises a first distributed feedback type single mode laser, a lithium niobate external modulator, a local oscillator electric signal source, an erbium-doped optical fiber amplifier, a polarization controller, a three-port optical circulator, a second distributed feedback type single mode laser and a photoelectric detector, wherein the first distributed feedback type single mode laser is used for generating optical carrier; the lithium niobate external modulator is used for externally modulating the optical carrier input by the first distributed feedback type single mode laser; the local oscillator electric signal source is used as a driving signal source of the lithium niobate external modulator; the erbium-doped optical fiber amplifier is used for amplifying an optical signal input by the lithium niobate external modulator; the polarization controller is used for controlling a polarization state of the optical signal input by the lithium niobate external modulator; the three-port optical circulator is used for performing unidirectional transmission on the optical signal input by the polarization controller; the second distributed feedback type single mode laser is used as an injected slave laser; and the photoelectric detector is used for performing photoelectric conversion on the optical signal input by the three-port optical circulator to generate a microwave carrier signal. By using the device, the microwave carrier signal with frequency which is several times the frequency of a local oscillator electric signal can be generated without being limited to an optical filter.

[Task] To provide the THz wave generator restricting increase in manufacturing cost or large size of the entirety of the apparatus and generating efficiently the several-W THz wave.[Means for Resolution] In a THz wave generator for generating a THz wave from a THz wave generating element by inputting a plurality of laser beams having different wavelengths to the THz wave generating element, at least one laser beam among the plurality of laser beams is formed into a pulse beam by the pulse generator and the pulse beam is amplified by an optical amplifier E and then the pulse beam is inputted to the THz wave generating element F. Preferably, the plurality of laser beams having different wavelengths are generated by inputting single wavelength beam to a multi wavelength generator from single mode laser light source and by inputting light waves having a plurality of wavelengths generated from the multi wavelength generator to wavelength selecting means.

Provided is a long cavity single-mode laser diode in which a ring waveguide is integrated such as a conventional array waveguide (AWG)-based laser or a concave grating (CG)-based laser.

The invention discloses an optical fiber type terahertz wave generation device and method based on modulation instability. The terahertz wave generation device based on modulation instability in optical fiber comprises a monomode laser, a phase modulation, a microwave source, an intensity modulator, an optical amplifier, a tunable filter, a photoelectric detector and an antenna. The optical fiber type terahertz wave generation device disclosed by the invention has simple and compact structure, can realize generation of tunable terahertz waves by adjusting the frequency of a microwave drive signal and has the advantages of greatly reducing the bandwidth requirements of the device and saving the cost of a system.

In a second harmonic, single-mode laser having a resonator including a Cr-doped fluoride laser crystal, first and second wavelength-selecting elements and a nonlinear optical crystal between a pair of laser mirrors, a wavelength-selecting width of the first wavelength-selecting element is {fraction (1 / 30)} or less of that of the second wavelength-selecting element, the first wavelength-selecting element is provided with a reflection coating having a reflectivity of 10-30% to the oscillated laser beam, such that the wavelength selection width of the first wavelength-selecting element is 0.02-0.03 nm, a wavelength interval in the oscillation wavelength range of the first wavelength-selecting element is 0.8-1.3 nm, and a wavelength selection width of the second wavelength-selecting element is 1.0-1.6 nm.

The invention belongs to the application optical field, and in particular relates to a generating device for radial polarized light applied to the optical tweezer technology particle capturing, surper resolution microscope, laser processing, and optical information storage. The generating device for radial polarized light comprises a first optical fiber, a second optical fiber, a single-mode laser light source, a polarizer, a first optical power coupler, a third optical fiber, a fourth optical fiber, a first optical fiber polarization state modulator and a second optical fiber polarization state modulator, a second optical power coupler, a fifth optical fiber and an imaging device. The generating device for radial polarized light is the all-fiber device, one beam of light with LP11 mode is stimulated, the light with LP11 mode is divided into two paths through the optical coupler for modulating the polarization state respectively, two paths of light with LP11 mode can be overlapped through the optical coupler, the optical fiber pattern theory and the coupling theory are combined and the space optical path system is not built, and the polarization controller is controlled for generating the polarized light different in vector.

The inventive configurable optical fiber polarization mode coupler is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing, and that are preferably optimized for use with photonic integrated circuits, such as coupling to dense optical input / output interfaces, wafer-level testing, etc. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Advantageously, at least one embodiment of the present invention comprises a phase locking optical fiber coupler comprising at least one optical fiber coupler configured as a pitch reducing optical fiber array (PROFA) component configured and optimized coherent combining of multiple optical fiber lasers to produce multi-kilowatt single mode laser sources.

The invention provides an odd frequency multiplication vector millimeter wave generation device and method without phase precoding, belonging to the technical field of electronic communication. The method comprises the steps that amplitude precoding is performed on an RF drive signal carrying sent data; then digital-to-analog conversion and power amplification are performed on the signal; a continuous wavelength optical carrier generated by a single-mode laser is injected into a phase modulator, and an amplified RF drive electric signal drives the phase modulator to output a series of sub-carriers; a wavelength selection switch selects two sub-carriers, the frequency interval of which is odd times of an RF drive frequency; and a single-ended photodiode performs heterodyne beat on the two selected sub-carriers, then analog-to-digital conversion is performed, and an offline digital signal processing module performs a corresponding odd multiple operation on the phase. The vector millimeter wave signal generation device and method omit the operation of phase precoding and have advantages that the structure is simple, implementation is easy, the cost is effective and the system performance is good.

The invention discloses a high coupling efficiency electric injection integration silicon-based laser, which is a laminated structure, and comprises a silicon substrate, an insulating layer, a large speckle semiconductor active chip, top layer silicon and a low refractive index layer. The upper surface of the silicon substrate is provided with a routine part and an etched part which is etched; the insulating layer is arranged on the routine part of the silicon substrate; the large speckle semiconductor active chip is arranged on the etched part of the silicon substrate; the top layer silicon is arranged on the upper surface of the insulating layer; the low refractive index layer is arranged on the side of the upper surface of the top layer silicon proximate to the large speckle semiconductor active chip. The high coupling efficiency electric injection integration silicon-based laser can directly and efficiently output single mode laser, and be commercialized, has the advantages of compact structure, simple process, and high efficiency and stability, and possesses a broad application prospect in the fields such as optical interconnection, optical communication, spectrum determination, optical remote sensing, etc.

The invention discloses a single-mode laser based on high-order surface gratings. The laser is of a ridge waveguide structure, and comprises a covering layer, a core layer and a substrate in a transverse direction. Narrow-groove-width high-order Bragg gratings are etched on a front segment ridge waveguide surface close to the output end of the laser, the etching depth of the group of gratings does not penetrate through the core layer, and optical feedback of the laser at the output end is provided; and a rear segment ridge waveguide of the other end of the laser does not contain gratings, an end face of the end is a deeply-etched interface, and optical feedback of the laser at the end is provided. The single-mode laser does not need secondary epitaxial growth of a material, and the manufacturing process is simple and convenient, thereby reducing the manufacturing cost of a device, and improving the reliability of the device; through introduction of the narrow-groove-width high-order surface gratings, radiation loss of the gratings is reduced, and laser performance is improved; and the laser rear end face formed by a deep etching method is easy to accurately position, the problem that the cavity length is indeterminate which is generated due to cleavage of an end face is avoided, and the laser is guaranteed to have good single-mode characteristics.

The invention discloses a gain optical fiber for outputting specific single-mode lasers. The gain optical fiber comprises a fiber core, a wrapping layer and a coating layer, wherein the fiber core, the wrapping layer and the coating layer are sequentially arranged from inside to outside. A rare earth ion doping area is contained in the fiber core of the gain optical fiber, a corresponding relationship exists between a distribution area of the rare earth ion doping area in the fiber core and light strength distribution of the specific single-mode lasers output by the gain optical fiber in advance, and the corresponding relationship refers that an area scope of distribution of the rare earth ion doping area in the fiber core is an area scope of I>(1 / 2)Imax in the light strength distribution of the specific single-mode lasers in the fiber core, wherein the I is the light strength of the specific single-mode lasers at any point in the fiber core, the Imax is the maximum value of the light strength, and the number of the Imax is larger than or equal to one. The gain optical fiber can achieve fundamental mode output of an optical fiber laser, can further achieve output of a specific single high-order mode of the optical fiber laser, and has actual guiding significance on mode control of the optical fiber laser.

A semiconductor laser device includes a substrate having a first surface and a second surface opposite to the first surface, an active region formed on the second surface of the substrate, a cladding layer formed on the active region, and an insulation region formed in the cladding layer to form on the second surface of the substrate a first laser region having a first size and a second laser region having a second size different from the first size. The first laser region is used for generating a first optical spectrum having a first laser mode channel space. The second laser region is used for generating a second optical spectrum having a second laser mode channel space. A combination of the first optical spectrum and the second optical spectrum forms a single mode laser. Without any gratings, the semiconductor laser device is easy to be fabricated and has a low fabrication cost.

The invention discloses a micro-fiber probe loss modulation-based polymer bottle micro-cavity single-mode laser component. The single-mode laser component comprises a glass slide, a micro-fiber, a polymer bottle micro-cavity and a pumping fiber probe, wherein the glass slide comprises a first glass slide and a second glass slide which are arranged in parallel, two ends of the micro-fiber are respectively arranged on the first glass slide and the second glass slide, the polymer bottle micro-cavity sleeves a middle part of the micro-fiber, the pumping fiber probe is arranged on the polymer bottle micro-cavity and is coupled to the polymer bottle micro-cavity, the polymer bottle micro-cavity is formed by curing a resin solution, and the constituent of the resin solution comprises a laser gain substance, a macromolecule organic solvent, high-viscosity resin and a curing agent. The single-mode laser component is implemented by changing a coupling position of the pumping fiber probe on an axial direction of the polymer bottle micro-cavity; and since great scattering loss is caused by photoluminescence of the pumping light probe at the coupling position, a high-order laser mode is pressured, a base mode in a symmetric center of the cavity is only simulated, so that the output of single-mode laser is achieved.