79 results about "Wavelength scale" patented technology

A birefringent interferometer system is described which uses nematic liquid crystal cells to produce variable optical path differences (OPD) between light of different polarization states that are interfered at a polarizing analyzer. Fixed retarders may also be incorporated to extend the range of OPD. The interferometer provides wide field-of-view, continuously variable path difference over a large range, and an on-board monitor of OPD for ensuring accurate settings of path difference, and hence, an accurate wavelength scale in the spectra produced by the apparatus. The system can further incorporate additional polarizing optics so it responds equally well to light of any incident polarization state without loss of efficiency.

PCT No. PCT/NO98/00031 Sec. 371 Date Jul. 29, 1999 Sec. 102(e) Date Jul. 29, 1999 PCT Filed Jan. 29, 1998 PCT Pub. No. WO98/36252 PCT Pub. Date Aug. 20, 1998A device for accurate and repeatable measurements of optical wavelengths, including an interrogation broadband light source (1) and a tuneable optical filter (2). A first part of the light is, in either order, transmitted through the filter (2) and reflected from, or transmitted through, at least one fibre Bragg grating (5) with known Bragg wavelength, providing an absolute wavelength reference, and directed to a first detector (7). A second part of the light is, in either order, transmitted through the filter and transmitted through, or reflected from a Fabry-Perot filter (8) with fixed and known free spectral range, creating a comb spectrum sampling the interrogation source spectrum to provide an accurate frequency/wavelength scale.

The invention discloses a spectrum scaling apparatus used for a spectrum imager. The apparatus is characterized in that: a light beam which is emitted by a broadband light source (1) goes through a diaphragm (2) and a collimating lens (3) and irradiates a wavelength tuning optical filter (4), a plurality of narrowband optical signals which are distributed in a comb-shaped mode and have different wavelengths are outputted, after light intensity adjusting by a broadband bandpass optical filter (5), the signals enter into an integrating sphere (9) from an integrating sphere incident light hole (6) for depolarization and space uniformity processing, and an integrating sphere light extraction hole (8) outputs a surface light source. A spectrum imager to be measured is placed on the light extraction hole (8) for spectrum scaling. According to the apparatus, a birefringence crystal is utilized to carry out light transmission rate modulation, a passband peak value position and a bandwidth size can be adjusted, a plurality of narrowband light intensity signals changing with a wavelength are provided in a broadband range, wavelength scanning is not needed when carrying out spectrum scaling on the spectrum imager, wavelength scaling with one-time imaging is realized, and the apparatus is suitable for scaling a large field of view and large caliber spectrum imager.

An element for reflecting, transmitting, focusing, defocusing or wavefront correction of electromagnetic radiation in the terahertz frequency range. The elements include a grid of conductive strips including active regions comprising a chalcogenide phase change material. The chalcogenide material can be in an amorphous, crystalline or partially crystalline state. The dispersive characteristics of the grid (e.g. impedance, admittance, capacitance, inductance) influence one or more of the reflection, transmission, state of focusing or wavefront characteristics of incident electromagnetic radiation through the action of a stored phase taper formed by establishing a crystallinity gradient over a series of active chalcogenide regions or domains in one or more directions of the element. The dispersive characteristics of the grid are determined by the structural states of the active chalcogenide regions contained therein and are reconfigurable through transformations of one or more chalcogenide regions from one structural state to another by providing energy to the chalcogenide material. In a preferred embodiment, the individual active chalcogenide regions are much smaller than the operating wavelength of the element so that a plurality of active chalcogenide regions is included in wavelength scale domains. In these embodiments, crystallinity gradients may be formed through monotonic increases or decreases in the domain average fractional crystallinity in one or more directions of an element where no particular requirement on the fractional crystallinity of individual active regions need be imposed. In these embodiments, the domain fractional crystallinity is a statistical average over the individual chalcogenide regions contained therein and phase tapers may be achieved in multistate or binary mode. The element may be free-standing, supported on a dielectric substrate or interposed between two or more dielectric materials.

The invention discloses a dielectric nano-brick array structure and the application thereof as a high-reflection film and a high-permeability film. The dielectric nano-brick array structure comprisesa substrate and a dielectric nano-brick array on the substrate. The dielectric nano-brick array is formed by periodically arranging dielectric nano-bricks and the dielectric nano-bricks are in a regular quadrangular prism shape. The bottom surfaces of the dielectric nano-bricks are square, wherein the length, the width and the height of the dielectric nano-bricks are sized in sub-wavelength scale.When the dielectric nano-brick array structure is used as a high-reflectivity film, the structural parameters of the dielectric nano-brick array structure are optimized. In this way, the Mie resonance can be generated when the s-wave and the p-wave are incident at a working wavelength. When the dielectric nano-brick array structure is used as a high-permeability film, the structural parameters ofthe dielectric nanometer brick array structure are optimized. In this way, the equivalent refractive index of a mixed layer is between the refractive index of a medium around the mixed layer and therefractive index of the substrate. According to the technical scheme of the invention, the high-reflection film and the high-permeability film, based on the dielectric nano-brick array structure, arehigh in working efficiency in the whole communication wave band.

A method for measuring the I-V characteristic and conversion efficiency characteristic of a dye-sensitived solar cell comprises the following steps: 1) sensitizing the IPCE characteristic data of the solar cell with a hardware measurement dye same to the ordinary solar cell IPCE measurement system: regulating a mercury lamp and the like to emit to the monochromator and keeping the wavelength scale of the monochromator consistent with that of the mercury lamp; 2) introducing the light of the mercury lamp into the monochromator with a mode of parallel emitting, connecting the standard reference batteries to two ends of the ammeter; 3) measuring the current signal of the reference battery under the illumination of 200nm homogeneous light, wherein the range of the measurement wavelength is 200nm-1100nm; 4) changing the dye-sensitived solar cell S1, and collecting data under same condition for calculating; and 5) measuring the I-V characteristic data of the dye-sensitived solar cell S1: regulating an analog light source, and adopting a balance bridge for compensating the circuit; regulating the constant pressure source, measuring the current flowing over the sample under the bias voltages of different scanning velocities, and obtaining the I-V characteristic.

The invention discloses an infrared multi-wavelength absorber, which comprises a substrate I 1, a structural layer I 2, an adhesive layer I 3, a dielectric layer 4, an adhesive layer II 5 and a structural layer II 6 in sequence, wherein the structural layer II 6 consists of a double cross structure array; the double cross structures are formed by splicing two cross structures; the angles of arrays in both x and y directions are 90 degrees; and the cycles in both x and y directions are of wavelength scale. According to the infrared multi-wavelength absorber, multi-wavelength absorption of an infrared band is realized by using the structure arrays of a single size; the infrared multi-wavelength absorber has a simple structural form and small thickness and is easy in control of the absorption characteristic; and the infrared multi-wavelength absorber has polarization characteristic and has broad application prospect in the application aspect of biosensors. A large volume of experimental data proves that the infrared multi-wavelength absorber has superior performance.

The present invention provides an optical microprobe device and method for focusing multimodal radiation with wavelength-scale spatial resolution and delivering the focused radiation to a specimen, including: a radiation source; and one or more of a plurality of optically transparent or semitransparent spheres and a plurality of optically transparent or semitransparent cylinders optically coupled to the radiation source; wherein the one or more of the plurality of optically transparent or semitransparent spheres and the plurality of optically transparent or semitransparent cylinders periodically focus radiation optically transmitted from the radiation source such that radiation ultimately transmitted to the specimen has predetermined characteristics. Preferably, the spheres or cylinders are assembled inside one of a hollow waveguide, a hollow-core photonic crystal fiber, a capillary tube, and integrated in a multimode fiber. Alternatively, the spheres or cylinders are assembled on a substrate. Optionally, the optical microprobe device also includes one or more of a waveguide, an optical fiber, a lens, and an optical structure disposed between the radiation source and the spheres or cylinders. Optionally, the spheres or cylinders are made from optically nonlinear or active materials that permit efficient nonlinear frequency generation and low-threshold lasing using the optical microprobe device.

This invention disclosed a FBG sensor and wavelength scaling device working in low temperature liquid helium circumstance. It consists of screw micrometer head and a cantilever dynamic platform. The characters are as follows: place the micrometer head and platform into a low temperature Dewar flask with liquid helium; a cantilever was fixed on the platform; the micrometer head was fixed on cover of the Dewar flask; one end of the head was connected to the displacement pole in the flask to form a force application device; the grating sensor of the FBG was sticked to the cantilever arm. The base and backbone of the cantilever arm were made of epoxy stuff.

A method and a sensor for detecting a target gas by laser spectroscopy using a laser or a laser diode having a monochrome emission wavelength that can be modulated by varying the operating temperature or the operating current. The wavelength range of the target gas comprises a first modulation of the laser or the laser diode over a first large modulation width, in addition to at least two absorption lines of a reference gas and at least one absorption line of the target gas. The absorption lines are used to calibrate the wavelength scale of the laser or the laser diode in relation to the varied operating temperature or operating current, a second modulation of the laser or the laser diode being performed over a second small modulation width, with the at least one absorption line of the target gas, for detecting the target gas.

The invention relates to a method for generating calibrated colour data of a target using colour measurement instruments distributed in the network comprising the steps A) generating at least one standard instrument profile for the colour measurement instruments distributed in the network to correct photometric and wavelength scale differences, and B) generating at least one geometry instrument profile for the colour measurement instruments distributed in the network to correct geometry scale differences. The method can be used in applications where colour measurement instrument networks are used, particularly in robotic systems where colour measurement instruments are integrated.

The invention provides a near-field microscopy system and a construction method thereof. The near-field microscopy system comprises an infrared/terahertz laser, a light path coupling module and an atomic force microscope. Accurate imaging and spectrum formation can carried out on morphology, physicochemical and molecular characteristics of a sample under a sub-wavelength scale. According to the photo-induced thermal expansion effect of infrared/terahertz dual-band adjustable radiation, thermal expansion deformation of the material is associated with infrared/terahertz characteristic absorption, and structural property information of the material is directly extracted through an atomic force probe. According to the invention, an infrared/terahertz optical detector does not need to be arranged at the far end, thereby avoiding violent signal attenuation caused by long-distance transmission; a reference light path does not need to be arranged, and the repeatability and reliability of material sub-wavelength structure information detection can be remarkably enhanced; meanwhile, the system has the advantages of being high in imaging speed, completely harmless to organisms, high in resolution ratio, capable of achieving multi-mode synchronous output and the like, and good complementation with existing existing mainstream medical imaging means is realized.

The invention discloses a space distribution PML model-based absorption material and a miniature dark chamber. A wave absorption unit comprises a grounding metal layer, a metal pattern and an intermediate-layer dielectric substrate, wherein the metal pattern is arranged on an upper surface of the intermediate-layer dielectric substrate, the intermediate-layer dielectric plate is arranged on an upper surface of the grounding metal layer, an electromagnetic wave polarized along a fixed direction irradiates the wave absorption unit at a known incident angle, and relative dielectric constant and areflection parameter of relative permeability conform to a certain condition by adjusting the size morphology of the metal pattern. An inner wall of the dark chamber is formed by closely arranging the wave absorption units, and for other positions, except an electromagnetic wave source fixed position, in the dark chamber, the wave absorption unit at the position is arranged according to an incident angle between the electromagnetic wave emission source and the position and according to the condition. An ultrathin absorption surface can be designed with a given frequency band, the wave absorption unit works in an opened or closed planar or curve-surface state with regard to different demands, and the wave absorption unit can be used for constructing the miniature wave absorption dark chamber with wavelength scale.

The invention discloses a high-efficiency super-surface vortex focusing lens, and relates to the technical field of optical lenses. The lens comprises a substrate and a phase wavefront that is arranged on the substrate and has vortex focusing characteristics; the phase wavefront is composed of a plurality of nano-columns, and the corresponding phase values are given according to the position points of the nano-columns to convert the incident plane waves into vortex light having an arbitrary orbital angular momentum and focus the vortex light at a specified focal length; and a wavelength-scaleenergy ring is formed. Since the adopted theoretical mechanism can make full use of the incident light energy in addition to absorption and reflection, the size and distribution period of nano-antennas are also optimized, and point-by-point phase modulation is performed on a target wavefront rather than region-by-region phase modulation, so that the designed super-surface vortex lens can achieve afocusing efficiency of up to 80%, and the wavelength-scale high-energy vortex light can be formed.

The invention discloses a pulse micro displacement sensor and a displacement measuring method thereof. The sensor comprises an infrared light source, a moving grating, a fixed grating, a first infrared photoelectric multiplier, a second infrared photoelectric multiplier, a first comb-like electrode, a second comb-like electrode, an upper-layer capacitor flat plate, a lower-layer capacitor flat plate, a cantilever beam in the shape of a Chinese character hui of the moving grating, a processing module for calculating the displacement according to the photoelectric signal and a current drive module for conveying current to the comb-like electrodes and the capacitor flat plates. When the interval of the two layers of the gratings is precisely controlled within the wavelength scale of 1/5 according to a special condition in a Wood abnormal phenomenon, the parameters such as period and duty cycles of the gratings are regulated; when the two layers of the gratings move, reflected light generates a pulse type change phenomenon which has slope higher than that of common Wood abnormal light intensity change flat curve, so that the tiny displacement signal can be greatly amplified to measure the displacement. Moreover, the dynamic range is expanded, the miniaturization is realized, and the application prospect in the military filed is wide.

In one aspect, the inventive concepts disclosed herein are directed to an antenna array system employing a current sheet array (CSA) wavelength scaled aperture. The CSA wavelength scaled aperture can include a first frequency region associated with a first operating frequency band and a second frequency region associated with a second operating frequency band. The first operating frequency band can include one or more current sheet sub-arrays having a respective plurality of first unit cells scaled to support the first operating frequency band. The second operating frequency band can include one or more current sheet sub-arrays having a respective plurality of second unit cells scaled to support the second operating frequency band. The CSA wavelength scaled aperture can include one or more capacitors each of which coupled to a respective first unit cell of the first frequency region and a respective second unit cell of the second frequency region.

The invention relates to a sub-gigahertz (Sub-GHz) low-profile 3D SRR (three-dimensional split ring resonator) metamaterial for increasing the radio frequency identification range. The metamaterial iscomposed of periodically placed sub-wavelength structures to generate a specific effect on incident electromagnetic waves. Generally, the electromagnetic metamaterials are 1/2 wavelength scales, while these metamaterials are typically used for high frequency applications from 10 GHz to 20 GHz. According to the application of sub-GHz, the unit size is actually too large, and the application of metamaterial in sub-GH is limited; The invention provides an innovative low-profile ultra-low frequency material design for a UHF (ultra-high frequency) RFID (radio frequency identification) tag. The tagworks from 860 MHz to 960 MHz. The metamaterial is an innovative 3D SRR (three-dimensional split ring resonator) structure. The 3D SRR structure achieves the expected ultra-low frequency specific effect through the design, simulation and test of the model. As the metamaterial can inhibit propagation of surface waves, the metamaterial is also very high in radiation efficiency.

The invention discloses an ultra-thin wave absorber based on deep sub-wavelength slits, which is characterized in that the thickness of a unit structure of the ultra-thin wave absorber is a deep sub-wavelength scale, namely, one percent wavelength magnitude and below, the ultra-thin wave absorber is divided into three layers along the height direction, namely, a metal patch, a dielectric spacer layer and a metal back plate from top to bottom, and an air slit with a deep sub-wavelength width is arranged between adjacent metal patches; the dielectric spacer layer is made of a low-loss material with the loss tangent value tan[delta] being less than 0.01, or the dielectric spacer layer is made of a lossless material; the wave absorbing wavelength is changed by changing the size of the metal patch and adjusting the thickness of the dielectric spacer layer so as to achieve wave absorption, and the wave absorber can work in all frequency bands from terahertz, microwaves to radio frequency. The thickness of the wave absorber is very small, the thickness of the wave-absorbing device is reduced to a few hundredths of wavelength from the traditional a few tenths of wavelength, and the wave absorber is very thin and light in weight and has certain flexibility; a mature circuit board process can be adopted for manufacturing, and the cost is reduced; and the wave absorbing effect is not sensitive to the incident angle, and the wave absorber has a conformal advantage and can cover the curved surface.