Abstract:
A method for determining a radius of elements suspended in a medium includes binding the elements to nanoparticles to form bound element-nanoparticle aggregates, superposing first and second Doppler-shifted optical waves having a variable frequency shift between them in the medium such that there is a gain in energy of the first optical wave with respect to the second optical wave, varying the frequency shift and measuring the gain while varying the frequency shift to determine the value of the frequency shift at which there is a peak in the gain, determining the radius of the bound element-nanoparticle aggregates based on the value of the frequency shift at which there is a peak in the gain, and determining the radius of the elements based on the radius of the bound element-nanoparticle aggregates.
Abstract:
. Described herein are systems and methods for digital data encryption, and more specifically, systems and methods for providing encryption keys for reading encrypted data. Optical media, particularly digital disks, are described where a laser reader accesses digital data on a disk. The disks are coated with a coating containing an encryption key to access encrypted data in the digital disk.
Abstract:
A solid state Raman laser (10) includes a laser pump (20) for producing a first radiation (22) at a high power and at a first wavelength along an optical path, a solid Raman active medium (30) in the optical path of the first radiation, the medium including single crystal diamond (32) having a first surface (34) and a second surface (36), where the first radiation at a high power produces stimulated Raman scattering in the medium and the medium generates a second radiation (38) at a second wavelength, a first optical element (40) in the optical path of the first radiation, wherein the first optical element allows the first wavelength to be transmitted and allows the second wavelength to be reflected, and a second optical element (50) in the optical path of the first radiation, wherein the second optical element allows the first wavelength to be transmitted and allows the second wavelength to be reflected.
Abstract:
A method and an apparatus are disclosed for limiting the readability of optically-readable medium, wherein a combination of a liquid crystal material and a wavelength shifting material are incorporated into the optically-readable medium. The liquid crystal material is selected to substantially interfere with the reading beam of a reading device. The wavelength shifting material is selected to shift the wavelength at which the liquid crystal interferes with the reading beam so that the reading beam can read the optically-readable medium. A predetermined stimulus causes the liquid crystal material to shift back to a configuration that substantially interferes with the reading beam so that the reading beam can no longer read the content on the optically readable medium.
Abstract:
A system and method for authenticating an item, including a photo luminescent material disposed on or in a substrate and capable of absorbing an incident radiation from a radiation source and emitting an emitted radiation having a spectral signature with a decay time after removal of the radiation source, and a photoauthentication device capable of being disposed in contact with the substrate and including the radiation source and a camera, where, in connection with providing the incident radiation and measuring the emitted radiation, the photoauthentication device is translated across the substrate while the photoauthentication device is disposed in contact with the substrate, and after translation across or over the substrate and the radiation source is not providing the incident radiation, the photoauthentication device is static with respect to the substrate and the camera is disposed over the photo luminescent material emitting the emitted radiation when the emitted radiation is measured.
Abstract:
A method and system for cleaning a secure instrument, such as a banknote, including a substrate, visual data and a security feature, including exposing the secure instrument to a supercritical fluid at a temperature and a pressure and for a duration sufficient to clean the substrate and not compromise the security feature and the visual data, wherein to clean the substrate includes to remove one or more substances from the substrate into the supercritical fluid. The substances removed from the substrate may include contaminants, dirt, sebum and pathogens.
Abstract:
A method of using a dye sensitized solar cell includes providing a dye sensitized solar cell having a first electrode having a transparent substrate of a first refractive index, a second electrode having a second transparent substrate of a second refractive index comparable to the first refractive index, and an electrolyte solution in a gap between the first electrode and second electrode. The electrolyte solution is removed from the gap and replaced with an inert fluid having a third refractive index comparable to the first refractive index and the second refractive index to allow light to pass through the cell substantially unrefracted. Alternatively, the inert fluid is in the gap between the first electrode and second electrode, and the inert fluid is removed from the gap and replaced with an electrolyte solution.
Abstract:
A method of generating a chemical and nuclear reactions includes providing a surface formed between a first medium and a second medium, the first medium having a first dielectric constant, ε, and the second medium having a second dielectric constant, ε s , wherein ε and ε s satisfy the relationship: Formula (I) depositing a plurality of like-charged parties, e.g. , ions or nuclei capable of fusion, in the first medium adjacent to the surface; and wherein a potential binding energy between the plurality of charged particles causes a distance between at least two of the charged particles to be sufficiently small to result in chemical reaction or nuclear fusion of the at least two charged particles.
Abstract:
A rechargeable photovoltaic cell includes a first electrode with a transparent substrate having a porous high surface area titanium dioxide layer thereon, and including a light absorbing dye. The rechargeable cell also includes a second electrode which includes a transparent electrically conductive substrate disposed apart from the first electrode so as to define a gap with the first electrode. A re-sealable seal provides access to the gap from the exterior of the cell. An electrolyte solution is located within the gap. Also provided is a method of recharging a photovoltaic cell, including opening a re-sealable seal, draining a first electrolyte solution fro a gap in a photovoltaic cell, flushing a first electrolyte solution from a gap, drying the gap and filling the gap with a second electrolyte solution and closing the re-sealable seal.
Abstract:
A rechargeable photovoltaic cell. In one embodiment the photovoltaic cell includes a first electrode with a transparent substrate having a porous high surface area titanium dioxide layer thereon, and including a light absorbing dye. The rechargeable cell also includes a second electrode which includes a transparent electrically conductive substrate arranged in spaced apart relationship with the first electrode so as to define a gap with the first electrode. A re-sealable seal provides access to the gap from the exterior of the cell. An electrolyte solution is located within the gap. Another aspect of the invention relates to a method of recharging a photovoltaic cell. In one embodiment the method includes draining the first electrolyte solution from gap in the photovoltaic cell, flushing the first electrolyte solution from the gap, drying the gap, and filling the gap with a second electrolyte solution all through a re-sealable seal.