583 results about "Linear optics" patented technology

A face-lit waveguide illumination system employing a planar slab or plate of an optically transmissive material. A light source is optically coupled a linear optical element which is attached to a face of the waveguide and is configured to inject light at an angle permitting for light propagation by means of a total internal reflection. Light is propagated through the waveguide towards a predetermined direction in response to optical transmission and total internal reflection. Light extraction features located along the prevailing path of light propagation extract light from the waveguide and emit such light towards a surface perpendicular. In one embodiment, the planar waveguide includes a window pane which provides light transport from one location, where light is injected through the face of the pane, to another location where light is extracted. Additional embodiments of the face-lit waveguide illumination system are also disclosed.

A method for producing low-noise laser output at wavelengths ranging from IR through visible to UV in various operation modes from a monolithic microchip laser comprises schemes of (1) generating one or two fundamental beam(s) from light source(s) selected upon the desired wavelength(s), polarization(s), and other features related to the desired laser output; (2) intracavity beam combination/separation due to the walk-off effect in one or more birefringent crystal(s) transparent to the propagating lights and highly anisotropic; (3) wavelength conversion in one or more nonlinear optical crystal(s); (4) compact and efficient pump source(s); and (5) minimization of intracavity loss/noise. One resonator cavity supports only one fundamental beam, which eliminates the green problem. The gain media can be selected from an extensive group of materials including isotropic and naturally birefringent crystals, with polarization dependent or independent laser emissions. Laser devices constructed in accordance with the inventive method are demonstrated with various configurations.

The application provides a low noise fiber laser frequency combs device with controllable carrier envelope phase shift frequency. The low noise fiber laser frequency combs device with controllable carrier envelope phase shift frequency comprises an optical path structure and a circuit structure, wherein the optical path structure comprises an oscillator, an acousto-optic frequency shifter, an optical fiber amplifier, a pulse compressor, an optical fiber spread spectrum device and a coherent heterodyne beat device; and the circuit structure comprises a feed-forward circuit control phase device and a phase-locked loop circuit control repetition frequency device. The fiber laser oscillator can ensure long-time operation of a system, so that the stability of the system is superior to that of a system adopting a solid laser oscillator; through the technologies of optimizing intracavity net dispersion of the fiber oscillator, introducing an inner cavity modulator in the oscillator, adopting the feed-forward acousto-optic frequency shifter, and the like, the low noise fiber laser frequency combs device can be realized; and meanwhile, due to the application of the acousto-optic frequency shifter, the carrier envelope phase shift frequency of the optical frequency combs can be accurately regulated, so that the optical frequency combs device with precise phase position regulation and secular stability is provided for realizing applications such as optical frequency standard, attosecond science and non-linear optics.

A linear optical sampling apparatus, temporally samples a modulated optical signal using the amplitude of the interference of its electric field with the electric field of a laser pulse. The apparatus includes a 90° optical hybrid that combines the optical signal and laser pulse in order to generate two quadratures interference samples S_A and S_B. A processor compensates for optical and electrical signal handling imperfections in the hybrid, balanced detectors, and A/D converters used in the optical sampling apparatus. The processor numerically scales the two quadratures interference samples S_A and S_B over a large collection of samples by imposing that the average <S_A>=<S_B>=0 and <S_A²>=<S_B²> and then minimizes 2<S_A·S_B>/(<S_A²>+<S_B²>)=cos(φ_B−φ_A)). This is done by adjusting the phase between the two quadratures (ideally either −π/2 or +π/2) so that cos(φ_B−φ_A)) is zero. The processor then generates a demodulated sample signal using the quadratures interference samples S_A and S_B. According to one feature, the hybrid sets the relative phase between two quadratures of their interferometric component so that the phase sensitivity inherent to linear optics is removed. A variety of hybrid arrangements is disclosed that can be implemented using integrated waveguide technology. The apparatus enables sampling of picosecond pulses up to 640 Gb/s with high sensitivity and temporal resolution.

The present invention relates to an apparatus and methods for achieving phase-matching between various waves and/or modes by operation of a waveguide. Phase-matching between interacting waves is achieved by total internal reflection and transverse Bragg reflection waveguides. Using second harmonic generation in GaAs/AlGaAs as an example, properties are investigated and quantified such as nonlinear coupling efficiency, bandwidth, tunability, and limitations due to dispersion. The technique is advantageous when compared to alternate technologies, where it is particularly attractive as a material independent means to obtain ultra-low-loss nonlinear optical elements for monolithic integration with coherent light source and other active devices.

A method for producing low-noise laser output at various wavelengths and/or in various operation modes in a monolithic microchip laser comprises schemes of generating two fundamental beams in separate cavities, precise intracavity beam combination based on the walk-off effect in birefringent crystal, and wavelength conversion in nonlinear optical crystals. The fundamental beams are produced from light sources selected upon the desired wavelengths, polarizations, and other features related to the laser output. Low-noise laser devices operated in SLM or with spectra of flat-top or desired bandwidths are constructed according to the method. High-volume fabrication is feasible. Apparatus of compact size and efficient frequency conversion is demonstrated with various configurations including those for generating low-noise 491 nm laser, as a replacement of Argon ion laser.

The invention relates to the non linear optical frequency conversion. To realize output of high power THz wave which can be continuously tuned, and stable running at room temperature, the technical scheme used by the invention is that: a tunable terahertz radiation source based on difference frequency cherenkov effect is composed of a laser device, a frequency doubling crystal, a double wavelength parametric oscillator, a harmonic mirror, a polarization filter, a combined beam mirror, a column lens and a difference frequency crystal; the harmonic mirror is placed between the frequency doubling crystal and the double wavelength parametric oscillator; the double wavelength parametric oscillator is II type phase matching KTP (Potassium Titanyl Phosphate) crystal OPO (Optical Parametric Oscillator); the polarization filter, the combined beam mirror and the column lens are arranged between the parametric oscillator and the difference frequency crystal; the difference frequency crystal is amagnesium oxide doped lithium niobate crystal with molecular formula of MgO:LiNbO3 or MgO:LN, and the generated THz wave is coupled and output by an Si prism on the side surface of the difference frequency crystal. The tunable terahertz radiation source based on difference frequency cherenkov effect is mainly applied to the optical frequency conversion.

The invention relates to a broadband Terahertz (THz) radiation generation and detection system and method. THz radiation is generated by optical rectification of an ultrashort pump pulse of a first wavelength having a duration in the picosecond- or sub-picosecond range in a first nonlinear optical crystal. The THz radiation is detected by electro-optic sampling or another appropriate method of a probe beam having a second wavelength in a second nonlinear optical crystal. According to the invention, at least one of the following conditions is fulfilled: a) the first wavelength is different from the second wavelength; b) the material of the first nonlinear optical crystal is different from the material of the second nonlinear optical crystal. This makes it possible to choose for the generation and for the detection process—independent of one another—the combination of wavelengths and nonlinear material and possibly other features of the pump/probe pulses like polarization with the highest efficiency for generation and detection of Terahertz pulses, respectively.

A plurality of Fabry-Perot interferometric sensors are optically coupled in series with each other to form an ordered optical series. Each Fabry-Perot interferometric sensor has a unique signalband and a passband. Each Fabry-Perot interferometric sensor has its unique signalband within the passbands of all of the next higher ordered Fabry-Perot interferometric sensors in the optical series so that a corresponding unique fringe signal from each of the Fabry-Perot interferometric sensors is a multiplexed output from the optical series.

This invention is a one-dimensional elementary motion detector that measures the linear optical flow in a small subsection of the visual field. This sensor measures motion by tracking the movement of a feature across the visual field and measuring the time required to move from one location to the next. First a one-dimensional image is sampled from the visual field using a linear photoreceptor array. Feature detectors, such as edge detectors, are created with simple circuitry that performs simple computations on photoreceptor outputs. The detection of the feature's location is performed using a winner-take-all (WTA) mechanism on feature detector outputs. Motion detection is the performed by monitoring the location of the high WTA output in time to detect transitions corresponding to motion. The correspondence problem is solved by ignoring transitions to and from the end lines of the WTA output bus. Speed measurement is performed by measuring the time between WTA output transitions. This invention operates in a one-dimensional subspace of the two-dimensional visual field. The conversion of a two-dimensional image section to a one-dimensional image is performed by a specially shaped photoreceptor array which preserves image information in one direction but filters out image information in the perpendicular direction. Thus this sensor measures the projection of the 2-D optical flow vector onto the vector representing the sensor's orientation. By placing several of these sensors in different orientations and using vector arithmetic, the 2-D optical flow vector can be determined.

The invention relates to a multi-mode non-linear optical microscopy imaging method and device. The multi-mode non-linear optical microscopy imaging device mainly comprises a laser system, an optical scanning microscope and a non-linear optical signal detecting and acquiring system. The multi-mode non-linear optical microscopy imaging device can work in a single-laser-beam mode and a dual-laser-beam mode and can realize multi-mode non-linear optical microscopy imaging such as two-photon excited Fluorescence (TPEF) imaging, multiphoton high-order harmonic (such as second harmonic generation SHG, and third harmonic generation THG) scattering imaging, coherent Raman scattering (such as anti-Stokes CARS) microscopy imaging) on isolated biological tissues and living cells, so that various non-linear specific optical signals of biological tissue samples can be obtained in situ, so that the important basis is provided for the optical diagnosis and deep analysis of the samples. Besides, a reflection measurement manner disclosed by the invention can be further directly applied to the acquiring of various non-linear specific optical signals of live animals and the microscopy imaging.

In an optical amplifier of the present invention, an input light is supplied to one end of an optical fiber connected to an output port, and the power of a light In an opposite direction which is input to the output port from the one end of the optical fiber, is measured, thereby obtaining a stimulated Brillouin scattering (SBS) occurrence threshold in the optical fiber based on the measurement result. Then, using the SBS occurrence threshold, a relation been the input light power and an occurrence amount of the self phase modulation (SPM) or the like in the optical fiber is obtained to be reflected on a control of the optical amplifier, so that an occurrence of the SPM or the like in the optical fiber is suppressed. As a result, It becomes possible to accurately measure, with a simple configuration, the nonlinear optical properties of the optical fiber actually connected to the output port of the optical amplifier, so that the optical S/N ratio degradation due to a nonlinear optical effect can be effectively suppressed.

The invention discloses a preparation method of a composite ZnO-mesoporous silica nanomaterial, namely a solvothermal in situ substitution method. The preparation method comprises the following steps of: uniformly mixing silicon-based molecular sieve powder, a ZnO precursor, a doping element and an organic solvent, adding the mixture into a high-pressure reaction kettle, and introducing a shielding gas to the reaction kettle for reaction; filtering the reaction mixture, washing, and drying to obtain dry powder; and heating and calcining the dry powder to obtain the composite ZnO-mesoporous silica nanomaterial. The composite ZnO-mesoporous silica nanomaterial prepared by the preparation method disclosed by the invention has the advantages of uniform ZnO loading, stable properties, excellent optical properties and catalytic properties and strong SHG (second harmonic generation) and TPL (two-photon luminescence) optical properties when used as an excellent catalyst for organic ester synthesis or as a laser nonlinear optical material, and is suitable for being prepared into a purple light-emitting material or a functional polymer additive. The preparation method disclosed by the invention has the advantages of wide and available raw materials, simplicity of operation and advantageous production cost.

Apparatus and methods for high fidelity quantum communication over long communication channels even in the presence of significant loss in the channels are disclosed. The invention employs laser manipulation of quantum correlated atomic ensembles using linear optic components, optical sources of low intensity pulses, beam splitters, and single-photon detectors requiring only moderate efficiencies. The invention provides fault-tolerant entanglement generation and connection, using a sequence of steps that each provide built-in entanglement purification and that are each resilient to the realistic noise. The invention relies upon collective excitation in atomic ensembles rather than single particle excitations in atomic ensembles so that communication efficiency scales polynomially with the total length of a communication channel.

In an apparatus for displaying a three-dimensional image, sub-pixels having color components are arranged in a longitudinal direction and in a lateral direction in a matrix form, in a display section for displaying a flat image, and a light ray control element is disposed so as to be opposed to the display section. In the light ray control element, linear optical openings extending in a vertical direction are arranged in the lateral direction. A sum of opening area lengths of opening areas of a plurality of sub-pixels adjacent to each other in a horizontal direction is varied in a single row, and the sum thereof in a plurality of rows becomes constant. Further, an arrangement of the sub-pixels is a color arrangement of a mosaic arrangement or a lateral stripe arrangement.

The invention relates to a large-sized bismuth barium borate non-linear optic crystal, which belongs to the orthorhombic system with a space group equal to Pna21 and a molecular formula equal to BaBiBo4. The crystal is made from a mixed system of bismuth barium borate, fluxing agent Bi2O3 and BaB2O4, or BaO and Bi2O3; the nonlinear optical effect of the crystal is approximately five times of that of (KH2PO4) KDP; and the crystal is transparent within a wave band of between 200 and 3,000 nm, and has the large size with 1 to 100mmx1 to 100mmx1 to 100mm. The large-sized bismuth barium borate non-linear optic crystal has the advantages of quick making speed, simple operation, low cost, large-sized and transparent crystal made by the non-linear optic crystal, wide light-transmission wave band, ideal mechanical property, infrequent fragmentation, stable physicochemical properties, no deliquescence and easy processing and preservation; moreover, the non-linear optic crystal can be used to make non-linear optical devices such as a multiple frequency generator, an upper frequency converter or a lower frequency converter and an optical parametric oscillator.

The invention relates to a large size potassium strontium borate nonlinear optical crystal, the preparation and use thereof. The formula of the crystal is: KSr4B3O9, which belongs to rhombic system, the space group is Pna2(1), and the molecular weight is 566.01, and the crystal size is 10-60mmx10-60mmx10-60mm. The preparation contains the following steps of: evenly mixing the potassium strontium borate compound with a fusing assistant, heating, maintaining the constant temperature, cooling to the saturation temperature and obtaining a mixture solution, placing a seed crystal into the mixture solution, lowering the temperature to the saturation temperature to obtain the required crystal, and subsequently extracting the crystal from the liquid level, cooling to room temperature, and finally obtaining the large size potassium strontium borate nonlinear optical crystal. The nonlinear optical effect of the crystal is approximately the same as the KDP, the transparent optical band is 220nm-3000nm. The crystal is simple in operation, low in cost, large in crystal size, short in growth period, less in coating, high in laster damage threshold, good in mechanical property, firm, stable in physicochemical properties, uneasy to deliquescence, convenient for processing and storage, or the like. Accordingly, the nonlinear optical crystal of the invention can be abroadly applied in nonlinear optical devices such as frequency doubler, optical parametric oscillator or the like.

The preparation method for transplantable ultrathin nano porous gold film comprises: preparing Au-Cu alloy with vacuum evaporation method, thermal annealing, and removing alloy with acidic solution. This product can be used in catalysis, bio-sense, porous electrode and other fields as well as nano grating and non-linear optics fields for special optical and high light transmission features

An amplified commonly mode-locked and/or Q-switched external cavity laser device with a plurality of gain elements and a plurality of amplifying elements is described. The device produces amplified optical pulses of picosecond to nanoseconds duration. The amplified pulses can be used in applications requiring large optical pulse energy and also high average optical power, such as material processing, nonlinear optics, extreme UV spectroscopy, and generation of x-rays.

A Raman fiber laser based on graphene oxide passive mode-locking belongs to the field of laser technologies and non-linear optics. The Raman fiber laser mainly comprises a pumping source (1), a combiner (2), a rare-earth doped optical fiber (3), a wavelength multiplexer optical fiber coupler (4), a Raman optical fiber (5), a circulator (6), a graphene oxide saturable absorber (7), an output coupler (8), a polarization controller (9) and the like. The Raman fiber laser adopts a dual-ring cavity structure, a single-ring cavity structure or a linear cavity structure. As the graphene oxide saturable absorber is used as a passive mode-locking device and the Raman effect of the optical fiber is combined, ultra-short pulse laser output with the characteristics of flexible wavelength, high stability and high energy is realized by the Raman fiber laser. The Raman fiber laser can be used in multiple fields such as communication sensing, bio-medical treatment and material processing.

The invention relates to a preparation method of strontium fluoroborate nonlinear optical crystals, and applications of the strontium fluoroborate nonlinear optical crystals. Compound synthesis is realized via solid phase reaction, and crystal growth is realized via flux growth method. The preparation method is simple in operation, and low in cost. The obtained strontium fluoroborate nonlinear optical crystals will not deliquesce in the air, possesses excellent mechanical properties and stable physico-chemical properties, is unbreakable, is convenient for processing, and is suitable for preparation of nonlinear optical devices. Frequency-doubled effect of the strontium fluoroborate nonlinear optical crystals obtained by the preparation method is three times of that of KDP, and the strontium fluoroborate nonlinear optical crystals can be widely used in nonlinear optical devices such as double frequency converters and optical parametric oscillators.