Abstract: A method for studying vibrational modes of an electro-acoustic device includes driving the electro-acoustic device to produce at least one vibrational mode therein, collecting phase and amplitude data from the electro-acoustic device using optical interferometry, and mapping the at least one vibrational mode based upon the collected phase and amplitude data. The phase and amplitude data may be processed to provide an instantaneous three-dimensional view of the at least one vibrational mode. Furthermore, a sequence of instantaneous three-dimensional views may be constructed to form a motion picture of the at least one vibrational mode. Additionally, collecting may include raster scanning to provide phase and amplitude data across a surface of the electro-acoustic device.

Abstract: The specification describes a technique for evaluating optical fiber splices. The essence of the technique involves detecting thermal power emanating from the fiber splice as the result of absorption of the light carried by the fiber. The technique is particularly suited for cladding pumped lasers wherein the splicing operation may introduce excessive absorption of pump laser radiation and excessive heating at the splice locale.

Abstract: Improved bandwidths and oscillation uniformity is obtained through a rod type BAW TFR structure formed over a semiconductor support. The resonator includes a first and a second electrode and a plurality of distinct elemental piezoelectric structures between the electrodes. Each of the piezoelectric structures has a length, a width and a height, the height being the distance between the electrodes. The height of the piezoelectric structures is at least equal to or more than one of the length or the width, or both. Such resonator is made by forming on a common bottom a plurality of distinct piezoelectric structures each having a length, a width and a height, wherein the height is formed at least equal to the width or the length of the piezoelectric structure, and forming a common top electrode thereover.

Abstract: The invention provides a device comprising an oriented, perovskite PZT layer on a diamond substrate, or other substrates such as silicon or platinum-coated materials. Vapor phase deposition processes are used to deposit a PZT layer onto a perovskite template layer on the substrate. The template layer is more readily deposited in a perovskite structure compared to PZT, and provides for nucleation and growth of the deposited PZT in perovskite form. The vapor phase deposition promotes the oriented structure of the resulting film. The structure is useful in a variety of devices, including surface acoustic wave devices.

Abstract: Embodiments of the invention include an improved diamond-based surface acoustic wave (SAW) filter device. The SAW device comprises polished, large-grained diamond in combination with a piezoelectric layer to enhance the acoustic velocity and operational frequency of the SAW device with reduced loss and increased efficiency. Also, the use of a pre-polished, large-grained diamond slab reduces processing complications such as contamination or stressing of delicate device circuitry adjacent to the diamond component. Alternative embodiments of the invention include planar or vertical interconnection schemes for packaging of the SAW device and also include planarization schemes for convenient deposition and patterning of the SAW device metallization layer.

Abstract: Many potential applications of CVD diamond film require the ability to remove a predetermined quantity of material from a surface of the film. We have discovered that such removal is advantageously accomplished by contacting the surface of the polycrystalline diamond film with a metal selected from Fe, Ni, Mn and Ti (preferably Fe and Mn, most preferably Mn), and maintaining the metal-contacted diamond film at a temperature in the range 600-1100° C. (preferably 800-1000° C.) without relative lateral motion between the film and the metal, for an effective time for removal of the quantity of material, exemplarily less than 100 hours. The metal can be in any appropriate form, e.g., a deposited layer, (including a patterned layer), a foil, or powder. We have also discovered that the local thermal conductivity of CVD diamond films typically increases with distance from the lower surface of an as-grown film.

Abstract: A system, e.g., a wavelength division multiplexed optical network, having a tunable add/drop filter is provided. The filter of the invention contains a substrate having a waveguide capable of guiding both optical waves and acoustic waves. An interdigital transducer induces one or more acoustic waves of desired wavelengths in the waveguide, along the same direction as the optical waves, such that one or more desired optical wavelength channels are reversed in direction, i.e., reflected back in the direction from which the light entered the waveguide. The filter of the invention thus provides reversal of direction of selected optical wavelengths in a manner similar to that of a fiber grating, but, unlike a fiber grating, the filter of the invention is also capable of being tuned in real-time to reflect light of selected wavelength bands, by adjusting the frequency of the voltage applied to the interdigital transducer.

Abstract: In accordance with the invention, the piezoelectric layer of a SAW device is mechanically coupled to a substrate of temperature-sensitive material having a large coefficient of thermal expansion or contraction. In a preferred embodiment, the temperature-sensitive material is a nickel/titanium alloy having high negative coefficient of thermal expansion of about -200.times.10.sup.-6. The frequency of the device can be tuned by changing the temperature of operation.

Abstract: In accordance with the invention, the operating frequency of a SAW device is magnetically tuned. In a first embodiment, the SAW device comprises a piezoelectric layer mechanically coupled to a substrate or body of magnetostrictive material. Strains magnetically induced in the magnetostrictive substrate is coupled to the piezoelectric layer, altering the velocity at which it can transmit acoustic waves. In an alternative embodiment, surface waves are directly generated in a magnetostrictive material and the velocity is directly altered by an applied magnetic field.

Abstract: Applicants have discovered a new method for fine polishing surfaces of metal-soluble materials such as diamond to the submicron level. The method involves applying to the material surface a polishing medium composed of metal powder and an acidic or basic carrier. The surface is then polished by high speed rubbing to a submicron finish. Several embodiments of apparatus for performing the polishing are described.

Abstract: In accordance with the invention, a microwave vacuum tube device, such as a traveling wave tube, is provided with an electron source comprising activated ultrafine diamonds. Applicants have discovered that ultrafine diamonds (5-1,000 nm diameter), when activated by heat treatment in a hydrogen plasma, become excellent room-temperature electron emitters capable of producing electron emission current density of at least 10 mA/cm.sup.2 at low electric fields of 10 V/micrometer. Sources using these diamonds provide electrons for microwave vacuum tubes at low voltage, low operating temperature and with fast turn-on characteristics. A multiple grid structure is described for providing high quality electron beams particularly useful for traveling wave tubes.

Abstract: This application describes a new method for rapid thinning, planarizing and fine polishing surfaces of diamond to the submicron/nanometer level so that large area, uniform thickness diamond wafers can be obtained. The method combines both chemical (dissolution of carbon in molten metals) and mechanical (rotating or moving sample fixtures in contact with the dissolving metals) polishing to achieve flat, smooth surface finishes in a relatively short period of time, thus improving the quality and economics of the overall polishing process. Several embodiments of apparatus for performing such chemical-mechanical polishing (CMP) of diamond are described.

Abstract: A novel technique for fine polishing surfaces of diamond to the submicron level involves applying to the diamond surface an oxygen-emitting polishing medium, either a dry powder or a powder dispersed in a liquid carrier. The diamond surface is then polished by high speed rubbing to a submicron finish by inducing oxygen emission and oxygen-carbon interaction. Several embodiments of apparatus for polishing are described.

Abstract: This invention involves apparatus for determining the thermal resistivities W.sub.s (=1/.kappa..sub.s) of electrically insulating, crystalline or polycrystalline samples under test (SUTs), all comprising host material such as CVD diamond. Once the optical absorptivities .alpha..sub.1 and .alpha..sub.2 and the thermal resistivities W.sub.1 and W.sub.2 of at least two other crystalline or polycrystalline bodies B.sub.1 and B.sub.2, respectively, comprising the same host material as the SUTs, and containing the same type of impurity or combination of impurities as the SUTs, are measured by some other technique--the inventive apparatus can then determine the thermal resistivities W.sub.s of the SUTs rather quickly from a measurement only of the optical absorptivities a.sub.s of the SUTs. These determinations of the thermal resistivities W.sub.s of the SUTs rely on our discovery that the following linear relationship exists: W=A+C.alpha.