Abstract: Methods and systems for germanium-on-silicon photodetectors without germanium layer contacts are disclosed and may include, in a semiconductor die having a photodetector, where the photodetector includes an n-type silicon layer, a germanium layer, a p-type silicon layer, and a metal contact on each of the n-type silicon layer and the p-type silicon layer: receiving an optical signal, absorbing the optical signal in the germanium layer, generating an electrical signal from the absorbed optical signal, and communicating the electrical signal out of the photodetector via the n-type silicon layer and the p-type silicon layer. The photodetector may include a horizontal or vertical junction double heterostructure where the germanium layer is above the n-type and p-type silicon layers. An intrinsically-doped silicon layer may be below the germanium layer between the n-type silicon layer and the p-type silicon layer. A top portion of the germanium layer may be p-doped.

Abstract: An apparatus adapted for confocal imaging of a non-flat specimen comprising a coherent light source for producing a light beam, imaging optics adapted to focus the light beam into at least one spot on a surface of a specimen, and a detector adapted to receive and detect light reflected from the specimen surface. The imaging optics comprise at least one optical component located so that the light reflected from the specimen surface passes therethrough on its way to the detector. The optical component is movable so as to move the at least one spot, within a range of movement, to a number of distinct locations in a plane perpendicular to the apparatus' optical axis, within the detector's integration time.

Abstract: Combined multifocal toric lens designs are disclosed which combine a correction for astigmatism, either corneal or lenticular, with a correction for presbyopia. One of the front and back surfaces of the lens defines a toric surface for an astigmatic optical correction, and one of the front and back surfaces, which can be the same surface or the opposite surface, defines a multifocal surface for a presbyopic optical correction, to provide visual acuity for astigmatic presbyopes. Embodiments are disclosed wherein one surface of the lens design has a combined concentric annular ring, multifocal toric surface, and the other surface of the lens design has a spherical or aspherical surface.

Abstract: An optical pickup head apparatus comprises a first coherent light source for emitting a coherent light serving as a main beam, and a second coherent light source for emitting a coherent light having a polarized plane at a right angle to the polarized plane of the coherent light emitted from the first coherent light source. When the coherent light emitted from the second coherent light source is incident upon a phase plate, the phase plate yields a sub-beam presenting a distribution of light intensity having peak values at at least both sides of the center of the sub-beam on a plane vertical with respect to the optical axis of the coherent light. Focusing means overlaps the main beam emitted from the first coherent light source on the sub-beam emitted from the phase plate, causing the resulting overlapped beam to be focused on the information-recorded surface of an optical disk.

Abstract: A magnet-optical disk drive device comprises a disc driving mechanism which includes a drive shaft powered by an electric motor. A magnet-optical disc is detachably connected to the drive shaft. A magnetic field modulation head is positioned at one side of the disc, and an optical unit is positioned at the other side of the disc. A moving mechanism is employed for moving both the magnetic field modulation head and the optical unit in a radial direction of the disc. The magnetic field modulation head is of a floating type wherein a head proper is forced to float above the surface of the disc due to the force of an air flow which is produced when the disc is rotated.

Abstract: A diode laser having an acitve layer bounded by confinement layers and two end facets that include etched mirrors selected to form an unstable resonator with good transverse mode quality. Energy from the unstable resonator is coupled out of the device through a transmissive window in one of the facets, the window providing a relatively large flux area and permitting higher output powers without loss of mode quality. Since stripe geometry is not used to control mode quality, a large current-carrying area is available, which reduces the current density and also permits higher output powers and longer operating lives.