摘要:
In accordance with the invention, an improved optical communication system employs light-generating devices comprising a phonon-tuned crystal alloy host doped with an optically active atom. In one embodiment, the crystal alloy host and optically active atom respectively comprise spinel and nickel. The spinel material is typically a solid solution between magnesium aluminate and magnesium gallate.
摘要:
A vibration-powered impact recording device that harvests power from vibrations that affect the device is provided. The recording device is affixed to an object and includes a vibration limit detection and recordation system. The system can include a suitable part that is fixed to the object, and a mass (or other suitable part) that is less firmly attached, with the relative motion between the two parts producing an electrical voltage. The electrical voltage can be used to power an information storage unit that records the details of the impact and optionally other sensors which record other parameters such as temperature, humidity etc. at the time of impact.
摘要:
Apparatus for processing a silicon workpiece uses reflected UV light to measure and control the workpiece temperature. A linearly polarized beam including UV light is directed onto a silicon surface to produce a reflected beam. The reflected beam is cross-polarized to null out much of the light, and the resulting residual reflectivity spectrum is determined. The temperature is determined from the characteristics of this spectrum. A workpiece heating station uses this measuring technique to accurately control the temperature of a silicon workpiece and temperature-dependent processing over a wide range of processing temperatures, including temperatures below 500.degree. C.
摘要:
Devices and methods for the measurement and control of fluid using one or two capacitors are described. The devices use Micro-Electro-Mechanical-Systems (MEMS) and radio-frequency inductive coupling to sense the properties of a fluid in a tube. The single and double capacitor devices may be coupled to shunts implantable in a patient and operable to be interrogated non-invasively. The shunts employing the novel capacitor devices are insensitive to stray signals such as the orientation of a patient's head. The devices are operable to employ a wireless external spectrometer to measure passive subcutaneous components.
摘要:
A process for device fabrication is disclosed in which two substrates having different crystal lattices are bound together. In the process the substrate surfaces are placed in physical contact with each other. A flexible membrane is placed in physical contact with a surface of one of the substrates. Pneumatic force is applied to the flexible membrane. The duration of the contact and the pressure of the contact are selected to facilitate a bond between the two substrate surfaces that results from attractive Van der Waals' forces between the two surfaces. The bulk of one of the substrates is then typically removed. Thereafter, the bonded surfaces are heated to a high temperature to effect a permanent bond.
摘要:
A process for device fabrication is disclosed in which two substrates having different crystal lattices are bound together. In the process the substrate surfaces are thoroughly cleaned and placed in physical contact with each other. The duration of the contact and the pressure of the contact are selected to facilitate a bond between the two substrate surfaces that results from attractive Van der Waals' forces between the two surfaces. The bonded substrates are heated to a moderate temperature to effect escape of gases which may be entrapped by the substrates. The bulk of one of the substrates is then typically removed. The substrates can be heated again to a moderate temperature to effect removal of any gases remaining entrapped on the substrates. Thereafter, the bonded surfaces are heated to a high temperature to effect a permanent bond.
摘要:
A method is disclosed for processing a silicon workpiece including a hybrid thermometer system for measuring and controlling the processing temperature where fabrication materials have been or are being applied to the workpiece. The hybrid thermometer system uses optical reflectance and another thermometer technique, such as a thermocouple and/or a pyrometer. Real-time spectral data are compared to values in a spectrum library to determine the “surface conditions”. A decision is then made based on the surface conditions as to how the temperature is measured, e.g., with optical reflectance, a pyrometer, or a thermocouple, and the temperature is measured using the appropriately selected technique. Utilizing the hybrid thermometer system, the temperature of a silicon workpiece may be accurately measured at low temperatures while accounting for the presence of fabrication materials.
摘要:
An optical identification system includes a light source with a broad wavelength spectrum that is directed on an object to be identified. Suitable optical components, such as, one or more collimating lenses gather light that is reflected from the object and direct this light into a spectrometer. The spectrometer disperses the collimated light using a dispersing element, such as one or more gratings, prisms or a combinations of both, onto an array of detectors. The array of detectors may be comprised of a linear diode array or a charge-coupled device (CCD) array which indicates the amount of light at each of a finely-spaced set of wavelengths covering a wide spectral range. The detectors are sensitive over a wavelength region, for example, in the case of silicon detectors from near-infrared plus the visible region, e.g., from 250 nm to 1100 nm. The set of signals from the detectors is read with an analog to digital converter, and transferred to a computer in the form of a spectrum. A set of known spectra determine the reference spectra and the unknown test spectrum is compared with the reference sets. A software program in the computer compares the test spectrum with reference spectra sets utilizing a statistical program. The program takes into account how much the known spectra vary from one another in addition to the average values. A display reads out a list of possible matches in rank order that have a probability of match greater than a predetermined threshold. An operator checks that the first listed item is correct and either accepts the first choice or indicates the correct choice. As an alternative, the system could automatically accept the first choice.
摘要:
An optical fiber formed from a glass preform substantially free of OH impurities is disclosed. The optical fiber is made to be free of OH impurities by a method having the steps of introducing a moving stream of vapor mixture including at least one compound glass-forming precursor together with an oxidizing medium into a tube, while generating a hydrogen-fee isothermal plasma on an outer surface of the tube to react the mixture and produce a glassy deposit on an inner surface of the tube. The glass preform is drawn to produce the optical fiber.
摘要:
A vibration-powered impact recording device that harvests power from vibrations that affect the device is provided. The recording device is affixed to an object and includes a vibration limit detection and recordation system. The system can include a suitable part that is fixed to the object, and a mass (or other suitable part) that is less firmly attached, with the relative motion between the two parts producing an electrical voltage. The electrical voltage can be used to power an information storage unit that records the details of the impact and optionally other sensors which record other parameters such as temperature, humidity etc. at the time of impact.