Abstract: An optical amplifier comprises a gain medium having an input surface and an output surface wherein the output surface is larger than the input surface. The gain medium may be frustum shaped. The optical amplifier includes a negative diverging lens to receive an extraction laser beam and to cause the laser beam to expand as the beam passes through the gain medium. The amplifier further comprises a positive collimating lens configured to receive the expanding amplified beam and reduce the divergence. The gain medium can be pumped by counter-propagating radiation. The fluence of the laser beam within the gain medium is configured to be near constant along the length of the gain medium and may be within 1.5-2.0 FSAT. The gain medium may be doped with dopant to provide gain, with larger concentration of dopants proximal the input surface and smaller concentration proximal the output surface.

Abstract: A magnetic bearing for supporting a spinning shaft in the radial direction and/or the axial direction includes a rotor formed on the shaft and a stator positioned around the rotor. Poles in the stator creates a magnetic field that supports the rotor. The number of poles is at least sufficient to produce a selected control force if there is an at least partial loss of current to one or more of the poles. The bearing also includes a set of permanent magnetic elements associated with the poles that create a homopolar, bias magnetic field. A controller connected to the poles is programmed with instructions to change the current to each pole in response to at least a partial loss of current to one or more of the poles and can include a current distribution matrix for determining a current value for each pole in such instances.

Abstract: A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Abstract: A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Abstract: A magnetic bearing for supporting a spinning shaft in the radial direction and/or the axial direction includes a rotor formed on the shaft and a stator positioned around the rotor. Poles in the stator creates a magnetic field that supports the rotor. The number of poles is at least sufficient to produce a selected control force if there is an at least partial loss of current to one or more of the poles. The bearing also includes a set of permanent magnetic elements associated with the poles that create a homopolar, bias magnetic field. A controller connected to the poles is programmed with instructions to change the current to each pole in response to at least a partial loss of current to one or more of the poles and can include a current distribution matrix for determining a current value for each pole in such instances.

Abstract: An optical fiber amplifier includes a length of silica optical fiber having a core doped with neodymium, a first cladding and a second cladding each with succeeding lower refractive indices, where the first cladding diameter is less than 10 times the diameter of the core. The doping concentration of the neodymium is chosen so that the small signal absorption for 816 nm light traveling within the core is less than 15 dB/m above the other fiber losses. The amplifier is optically pumped with one laser into the fiber core and with another laser into the first cladding.

Abstract: An input apparatus or keypad (14) for computers and networks is provided. The keypad (14) has a palm size housing (20) having an extended opening (30) in its top surface (28). An input or key assembly (32) mounted in the opening (30) has a number of keys (34) arrayed in a 6 by 4 matrix, for example, to which operator can access to input information. The housing (20) includes a processor for processing information input using keys into a corresponding signal, and a transmitter for transmitting the resultant signal to a receiver of the computer or network by wireless. In particular, the keypad (14) is designed ergonomically so that the operator can learn an input operation with ease and time-consuming and push keys so quickly.

Abstract: A dental treatment chair assembly with a treatment chair for keeping a patient in sitting position or in supine position, characterized by a treatment chair (bed) having a headrest for holding the head of a patient, and a backrest for holding the back and the waist of the patient, and instrument connection ports detachably connected to a dental treatment instrument which are disposed at the back or the side of said headrest, or at the back or the side of the backrest near by the headrest. In the preferred embodiment, the headrest is inclinably supported by the backrest, and a projecting part turning above is provide for compensating an estrangement between the headrest and the backrest.

Abstract: A system for use in skill acquisition, transfers and verification for performer has a simulated object, i.e., simulated head, to which the performer would perform clinical procedure. An image pickup, e.g., CCD camera, picks up an image of a point indicator provided on the performer or an instrument. Using the picked-up image, an image signal corresponding to the picked-up image is made. An image processor processes the image signal and generates data for showing a movement or tracks of the point indicator on a two-dimensional coordinate system. Thereby, a display shows tracks of the point indicator by using coordinate data.

Abstract: A dental treatment chair assembly with a treatment chair for keeping a patient in sitting position or in supine position, characterized by a treatment chair (bed) having a headrest for holding the head of a patient, and a backrest for holding the back and the waist of the patient, and instrument connection ports detachably connected to a dental treatment instrument which are disposed at the back or the side of said headrest, or at the back or the side of the backrest near by the headrest. In the preferred embodiment, the headrest is inclinably supported by the backrest, and a projecting part turning above is provide for compensating an estrangement between the headrest and the backrest.