Abstract

A pump system for a high-power holmium-doped fiber optic laser is provided, comprising: a 1.13 micron pumping means composed of: a coreless fiber and a light absorber; high and low reflection Bragg gratings at 1.135 microns, which form a ytterbium fiber laser cavity; high-power 915 nm laser diodes pumping the ytterbium fiber; and a high reflection Bragg grating (HR-FBG) at 2.07 microns; and a 2 micron laser formed by a holmium-doped fiber (HDF) that forms, with the high reflection Bragg grating at 2.07 microns, a holmium-doped fiber laser cavity, where each 915 nm photon of the 915 nm laser diodes that is converted into a 1.13 micron photon releases additional energy in the form of heat.

IPC Classes  ?

• H01S 3/0941 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a semiconductor laser, e.g. of a laser diode
• H01S 3/04 - Arrangements for thermal management
• H01S 3/067 - Fibre lasers
• H01S 3/094 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
• H01S 3/16 - Solid materials

Abstract

The present invention relates to a pumping system for a high-power holmium-doped optic fibre laser, said system comprising: a 1.13 micron pumping means made up of a core-free fibre and a light absorber; Bragg gratings with high and low reflectivity at 1.135 microns that form a ytterbium fibre laser cavity; high-power 915 nm laser diodes that pump the ytterbium fibre; a high-reflectivity Bragg grating (HR-FBG) at 2.07 microns; and a 2 micron laser formed by a holmium-doped fibre (HDF) that forms, with the high-reflectivity Bragg grating at 2.07 microns, a holmium-doped fibre laser cavity, wherein each 915 nm photon of the 915 nm laser diodes that is turned into a 1.13 micron photon releases additional energy in the form of heat.

IPC Classes  ?

• H01S 3/067 - Fibre lasers
• H01S 3/16 - Solid materials
• H01S 3/0941 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a semiconductor laser, e.g. of a laser diode

Abstract

In alternative embodiments, provided are moiré profilometry methods for analyzing a topography of an object comprising use of dual patterns that are simultaneously projected onto a surface of the object from two symmetric directions. In alternative embodiments, the projected dual patterns superimpose and generate a fringe pattern that contains a moiré pattern, the moiré pattern having a phase that is modulated according to the topography of the object. In alternative embodiments, the moiré pattern is extracted from the fringe pattern using a spatial or temporal method, and the phase is demodulated from the extracted moiré pattern using a spatial or temporal method.

IPC Classes  ?

• G01N 21/45 - RefractivityPhase-affecting properties, e.g. optical path length using interferometric methodsRefractivityPhase-affecting properties, e.g. optical path length using Schlieren methods
• G01B 11/25 - Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures by projecting a pattern, e.g. moiré fringes, on the object

Abstract

The invention relates to a system for early detection of diabetic foot syndrome, made up of: a raised platform with a seat on which the patient is placed; a base structure, which comprises an upper supporting plate and a lower supporting plate, wherein said upper supporting plate comprises a pair of windows, made of a transparent material, on which the patient places their feet; a terahertz (THz) image capturing system located on said lower supporting plate under the windows; and a PC, which communicates with said image capturing system in order to control same, and which comprises an algorithm for generating an image of the hydration of the foot; said THz image capturing system is made up of a pair of lenses placed at an angle; a photoconductive terahertz emitting means for emitting a THz signal towards the feet of the patient; a photoconductive terahertz detection means which receives the THz signal reflected by the feet of the patient, wherein said reflected THz signal corresponds to a THz pulse measurement in the reflection time domain; a positioning system, which moves the lenses and the emitting and detecting means along the windows to capture the THz pulses along the entire sole of both feet; wherein said PC processes each measurement of said THz pulses via said algorithm and generates an image of the hydration of the foot and reports specific hydration values, by using a Fresnel coefficient.

IPC Classes  ?

• A61B 6/08 - Auxiliary means for directing the radiation beam to a particular spot, e.g. using light beams
• G01N 21/3586 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared lightInvestigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using Terahertz radiation by Terahertz time domain spectroscopy [THz-TDS]

Abstract

The invention relates to the technical field of optics as it specifically relates to oxyfluorinated glass-ceramic nanoparticle compositions with high upconversion contaminated with rare earth ions, which are luminescent nanomaterials obtained by means of the melt-quenching technique. The compositions of the present invention are formed by an easier production process that that described in the prior art, as the production time is shorter (less than 3 hours) and the concentrations of the active ion (lanthanides) are lower (by up to one order of magnitude), which reduces the use of materials in order to obtain emission intensity which is comparable with, or higher than, NaYF4.

IPC Classes  ?

• C03C 3/23 - Silica-free oxide glass compositions containing halogen and at least one oxide, e.g. oxide of boron
• C03C 3/247 - Silica-free oxide glass compositions containing halogen and at least one oxide, e.g. oxide of boron containing fluorine and phosphorus
• C03C 4/12 - Compositions for glass with special properties for luminescent glassCompositions for glass with special properties for fluorescent glass
• C03C 10/16 - Halogen-containing crystalline phase

Abstract

The invention relates to a method that is characterised in that it can be used to design aspheric lenses having "zero spherical aberration", which can be represented using parametric mathematical functions with a method that can be used to calculate the thicknesses of the lenses in a precise manner, thereby avoiding the use of series approximation used in the optical industry to design lenses and eliminating the concept of "reduced spherical aberration". The aforementioned lenses can also be used to improve the visual health of many people, owing to the fact that they have no spherical aberration. The anterior or posterior corrective surfaces (noting that the designs are reversible) can be easily produced using different manufacturing processes, such as CNC machining and moulding. Assuming that: a) all of the incident radiation is completely refracted; b) the material of the lens is ideally isotropic and homogeneous; c) it is immersed in a medium that is also isotropic and homogenous; and d) the refracting interfaces are ideally continuous, the resulting lenses with "zero spherical aberration" to be designed using this method have an optimum image point spread function (PSF) for an on-axis object point, with waves that "converge towards" or "diverge from" the image point, as a byproduct of: the successive internal reflections of the light that is not radially polarised, the maximum resolution of the surface at an atomic scale, and the self-phase modulation and the non-linear dispersion effects if the light intensities are very high. These waves can also be refracted in the positive direction of axis z, since the electric field of the wave is always oscillating in the plane r-z; thereby producing an image of the object point with spread, which must not be confused with spherical aberration or diffraction effects. The invention paves the way for a new generation of optical instruments and lenses that will allow progress in many human disciplines.

IPC Classes  ?

• G02B 3/04 - Simple or compound lenses with non-spherical faces with continuous faces that are rotationally symmetrical but deviate from a true sphere

Abstract

The invention relates to a method for producing parastigmatic surfaces and lenses, and to parastigmatic surfaces and lenses produced by this method, for use in the ophthalmological and optometrical fields, both in optical diagnostic and evaluation devices and instruments, and in optical vision correction elements. For that purpose, superficial refractive surfaces or sectors that specify smooth changes in curvature between main orthogonal or non-orthogonal meridians are specified, in an inharmonic form, according to an analytical expression with polar co-ordinates involving a recursive variable that is a function of ophthalmic parameters, such as the apical curvatures in the main meridians, the conic constants of the main meridional curves, the positioning angle of the first main meridian, parastigmatism and the eccentricity thereof. These thus described parastigmatic surfaces are produced, in combination with other conventional surfaces, such as spherical, cylindrical, toric, aspherical surfaces, etc... by means of production techniques such as machining, moulding, ablation, printing, shaping and others.

IPC Classes  ?

• G02B 3/02 - Simple or compound lenses with non-spherical faces
• G02C 7/02 - LensesLens systems