61 results about "Excitation spectroscopy" patented technology

A method for the conduct of a measurement of proximity between luminescent species based on detection of transfer of excitation energy between them. A first photoluminescent species (the "donor") and a second photoluminescent species (the "acceptor") are provided and are such that the donor species and the acceptor species have at least some excitation spectral regions which differ and that at least a part of the emission spectrum of the donor overlaps with at least a part of the excitation spectrum of the acceptor. The donor species is excited with a cyclical temporal sequence of wavelength bands, optionally provided as pulses or modulated in intensity, giving rise to a characteristic temporal fluctuation in emission therefrom and emission in at least one wavelength band characteristic of the acceptor is analyzed to detect the presence of the said characteristic fluctuation or a subcomponent thereof and optionally also to detect a fluctuation characteristic of direct excitation of the acceptor.

An object of the present invention is to provide fluorescence showing a peak wavelength of excited spectrum within the wavelength range of from 350 to 500 nm and suitable for a white LED emitting yellow light, and a white LED comprising this fluorescence. This object achieved by phosphor for white. LED comprising a silicate fluorescent material and a borate fluorescent material.

This invention discloses an Excitation Emission Matrix (EEM) fluorescence spectrometer system that uses an LED array to cause excitation emission matrix fluorescence that is imaged onto a spectrograph for sample identification and analysis. By using the LED array, the spectrograph requires only high spectroscopic resolution of about 1 to 5 nm in the fluorescence emission range and low excitation light resolution of about 14 to 73 nm in the excitation range. While individual LED optical excitation spectra may contain wavelength regions that overlap, as long as the various LEDs have different excitation wavelengths and intensities, spectral overlap does not preclude data analysis. The invention provides an EEM spectroscopy system that is not a high resolution such as a laser or lamp based excitation system, but instead uses a lower resolution, lower power LED system. The invention also provides results that are comparable to existing systems with lower component cost and lower power requirements while also optically stable, small, and easy to use.

The invention relates to a live body fluorescent endoscopic spectrum imaging device, comprising a light source unit, a light split unit, a scanning light guide unit, a fiber bundle endoscopic unit, an electrooptical signal detection and acquisition unit and a computer, wherein the light source unit consists of a collimating unit and a band filter. The imaging device is characterized in that the light of the collimating unit passes through the band filter and then enters the light split unit, the light split unit is provided with two paths of interfaces, one path of the interfaces of the light split unit is connected with the scanning light guide unit, the scanning light guide unit is connected with the fiber bundle endoscopic unit, and the other path of the interfaces of the light split unit is connected with the electrooptical signal detection and acquisition unit which is connected with the computer. The imaging device has the characteristics that: 1, a Fourier transform spectrometer is used to detect a sample excitation spectrum, and has the advantages of high spectral resolution (1nm), adjustable spectral resolution and the like; and 2, the fluorescent live body endoscopic spectrum imaging system can provide not only imaging diagnosis at tissue level but also spectrum diagnosis at molecular level.

The embodiment of the invention relates to a spectral analysis method in the field of element spectral analysis. The method comprises the following steps: analyzing the spectrum of a guide sample, and determining the relationship between a peak wavelength and a peak position and the relationship between the peak wavelength and a peak width; calculating possible peak positions and peak width in the excitation spectrum of elements contained in a sample to be tested by the determined relationships; carrying out peak searching in the whole spectral range of the sample to be tested, comparing a peak position obtained by peak searching with the calculated peak position, and comparing a peak width obtained by peak searching with the calculated peak width so as to determine whether a complete overlapped peak exists or not and determine the width of an overlapping region; carrying out peak decomposition in each overlapping region and calculating the mathematical expressions of a gauss function and a background function; and carrying out spectral analysis by utilizing the obtained gauss function and the background function. The embodiment of the invention achieves the purpose of peak decomposition, and provides more accurate and detailed data for subsequent elemental analysis and quantitative analysis.

A spherical phosphor includes a fluorescent substance having a maximum excitation wavelength of 400 nm or longer; and a transparent material containing the fluorescent substance, in which, in an excitation spectrum, an excitation spectral intensity in a wavelength region of from 340 nm to 380 nm is 50% or higher of an excitation spectral intensity at a maximum excitation wavelength. A wavelength conversion-type photovoltaic cell sealing material includes a light-permeable resin composition layer that contains the spherical phosphor and a sealing resin.

The invention discloses a manganese-doped titanate-based red luminescent material and a preparation method and an application thereof. The red luminescent material has the chemical general formula of BaAl6TiO12:xMn<4+>, wherein x is the Mn<4+> doped molar percentage coefficient, and 0.001<=x<=0.25; the red luminescent material can be prepared by using a high temperature solid phase method or a sol-gel method, moreover, has good chemical stability, can emit red rays with the wavelength range of 620-750 nm when excited by ultraviolet, near ultraviolet, blue rays or other excitation light sources, has broader excitation spectral range, has strong absorption at the wavelength of 355 nm, and is perfectly matched with commercial blue chips.

A semiconductor light emitting device includes: a semiconductor light emitting element; a first phosphor which absorbs light emitted from the semiconductor light emitting element and emits first wavelength-converted light; and a second phosphor which absorbs light emitted from the semiconductor light emitting element and emits second wavelength-converted light. The first phosphor has a first excitation spectrum region where excitation intensity increases with increasing wavelength around a peak wavelength of the semiconductor light emitting element. The second phosphor has a second excitation spectrum region where excitation intensity is flat or decreases with respect to increasing wavelength around the peak wavelength of the semiconductor light emitting element.

The present invention is a method and system for reducing contamination in the resulting plasma of a weld produced by a fiber laser. The invention establishes the fiber laser in an optimal configuration for applying a high density beam to a weld material that eliminates spectral interference. The beam is applied in a narrow bandwidth of 1064 nm+/−0.5 nm in one operative condition using an inert shielding gas, preferably argon, in a cross-flow or controlled environment around the welding region to prevent contamination of the plasma forming in the weld region. The method is optimized by determining and avoiding the emission spectrum for the fiber laser and the cover gas or gasses as well as any particular excitation spectra for the weld material. The system can utilize a single laser input, or can utilize multiple lasers joined by coupling means and utilizing a switch to select one or more of the fiber lasers.

The invention discloses a data processing method for effectively solving a multi-component overlapped three-dimensional fluorescence spectrum based on differential spectrum. The method comprises the following steps of: by carrying out two-dimensional expansion on a three-dimensional fluorescence spectrum and expanding the three-dimensional fluorescence spectrum into a excitation spectrum and a transmission spectrum; respectively calculating differential spectrums of the excitation spectrum and the transmission spectrum; before carrying out the differential spectrum calculation on the excitation spectrum and the transmission spectrum, carrying out cubic spline interpolation on the excitation spectrum, and carrying out roughness punishment smoothing treatment on the transmission spectrum; and finally carrying out independent component analysis to realize the accurate component identification and single component extraction of a multi-component mixture, thereby realizing the precise separation of a multi-component three-dimensional fluorescence severe overlapped spectrum and the accurate identification and extraction of the components. The method is applicable to data processing on all multi-component three-dimensional fluorescence aliasing spectrums which use a three-dimensional fluorescence spectrum technique as analysis means; method basis for further application of the three-dimensional fluorescence spectrum technique is provided, and the method has very wide application prospect.

A system and method for authentication of secure products is disclosed. The security feature contains a first component in the form of an emitter capable of emitting light in response to external pump light. The security feature also contains a second component in the form of a taggant that absorbs light in a spectrally narrow range compared to the broader excitation spectrum of the first material. In this manner the emitter and taggant work in combination with one another to create an emission response significantly dependent on the illumination wavelengths and unique to the specific combination of the components. The emitter and taggant can be in the form of a mixture. Further the emitter and taggant may be applied in close proximity to one another, such as within two separate coating layers on a suitable substrate.

A part of pre-treated water flowing into an ultraviolet irradiation tank is guided to a fluorometer. The fluorometer scans an excitation spectrum peak wavelength of the pre-treated water at a fluorescence wavelength fixed to 425 nm to obtain an excitation spectrum, and continuously measures an excitation peak wavelength thereof. Based on the analysis result obtained by the fluorometer, an ultraviolet irradiation device calculates an ultraviolet irradiation level target value for optimizing an ultraviolet irradiation level, and thus controls the irradiation level of ultraviolet rays emitted therefrom.

The invention discloses a Eu3+doped tantalite red fluorescent powder and a preparing method and application therefore. The fluorescent powder is La2-2xEu2xTa12O33, wherein x is the Eu3+doped chemical metering score and is larger than or equal to 0.001 and smaller than or equal to 0.20, the high-temperature solid phase method is adopted, rare earth ions are added, and the Eu3+doped tantalite red fluorescent powder is prepared. The Eu3+doped tantalite red fluorescent powder can be effectively excited by near ultraviolet light and blue light nearby 250 nanometers to 475 nanometers, the emission wavelength of the Eu3+doped tantalite red fluorescent powder and the emission wavelength of a near-ultraviolet LED chip are quite coincident, and under excitation of the near ultraviolet light, the fluorescent powder can emit bright red fluorescence, the emission wavelength is mainly 612 nanometers, and the red fluorescence has the quite-wide excitation spectrum and the quite-wide luminescence spectrum; the obtained granularity is even, the luminous efficiency is high, the chemical stability is good, toxic gas such as sulfide cannot be generated under ultraviolet radiation, the environment is friendly, and the Eu3+doped tantalite red fluorescent powder can be applied to white light LED and the other luminous fields; in the preparing process, compounds with elements required by synthetic materials are mixed in proportion, the high-temperature solid phase method is adopted, the technology is simple, the Eu3+doped tantalite red fluorescent powder is free of pollution, environmentally friendly and suitable for industrial production.

The invention relates to a method for identifying fluorescence of wood. The method comprises the following steps: A. grinding the wood to be determined into wood flour and extracting a fluorescent substance in different polar solvents to obtain different solutions; B. primarily determining the strongest emission spectra of the solution to obtain the primary strongest emission wavelength; C. determining the strongest excitation spectrum of the solution, and a solvent with the unique characteristic peak, and obtaining the accurate strongest excitation wavelength and fluorescence intensity thereof; D. accurately determining the strongest emission spectrum of the solution, and obtaining the accurate strongest emission wavelength and fluorescence intensity thereof; E. comparing the obtained strongest emission wavelength and fluorescence intensity thereof with a spectrum of the known wood to obtain the specific tree species of the wood to be determined. The identifying method provided by the invention has uniformity and reproducibility, and can be widely used.

A light emitting device is provided to produce white light with a stable correlated color temperature and stable color coordinates. The light emitting device includes a blue LED chip and a yellow phosphor. The blue LED chip has a peak wavelength X slightly smaller than the peak wavelength Y of the phosphor such that when the light emitting device is subjected to a predetermined operating current, the phosphor decays due to thermal effect, and the LED chip has its emission spectrum red-shifted to substantially match with the excitation spectrum of the phosphor. At this time, the excitation ability of the LED chip is increased and causes an increase of yellow power output from the phosphor that substantially compensates a decrease of yellow light output caused by the phosphor.

A new technique which uses a pump-probe methodology to place a molecule into one or more excited rotational and/or vibrational states. By evaluating spectral changes due to at least one discrete frequency of pump photons a multi-dimensional characterization of the molecule's excited state energy level results. This multi-dimensional characterization typically involves evaluating the changes between excited and unexcited state measurements. The differential nature of the evaluation makes the technique self-referencing and solves problems common to many spectroscopic techniques. The multi-dimensionality of the technique provides high specificity and immunity to interferents. The preferred embodiments involve excitation by using photons suited to pumping the rotational states and evaluating the effects by probing the energy levels of one of more vibrational states. The technique is capable of detecting bulk and trace concentrations of a molecule in gas, liquid and solid phases, both in pure form and in the presence of other molecules.

The invention provides a spectrum on-line diagnosis method and device. The problem of poor application effect of an existing excitation spectrum on-line measurement system in a high-temperature stateis solved. The spectrum on-line diagnosis method comprises the following steps that (1) a conjugate reflecting surface is established, and a sample and a detection assembly are placed at a focal pointA and a focal point B of the conjugate reflecting surface separately; (2) the sample is heated to realize high temperature/high temperature rate conditions; and (3) detection light is incident to thesurface of the sample to generate reflection or Raman scattering, the reflection or Raman scattering light is reflected and converged by the conjugate reflection surface and then is incident to the focal point B and enters the detection assembly, spectral signals are received and detected, and a reflection or scattering spectral curve of the surface of the sample in the temperature change processis calculated and given. The spectrum on-line diagnosis method and device has the characteristics of real-time online, high test precision, pollution resistance, simple structure and the like.

The invention relates to the field of photo-functional materials, in particular to a red light excited fluorescent dye. The red light excited fluorescent dye has a structure shown as the formula (I) in the description. The red light excited fluorescent dye has quite wide excitation spectrum, is good in photostability and high in sensitivity, realizes trace detection, can be used in different application fields such as cell imaging, fluorescence probes, laser dyes, fluorescence sensors and the like, and shows good practicability. According to the preparation method, raw material cost is low, nopollution is produced, the process is simple, and yield is high; the prepared fluorescent dye is novel in structure, good in performance and suitable for being widely applied in the fields of biology, environment and the like.