Pencom International Corporation

Other

Hoetron, Inc.

Laser Magnetic Storage International Company

Xerox Corporation

Blue Sky Research

Xidex Corporation

Wai-hon Lee

Lee, Wai-hon

Wai-Hon Lee

James J Snyder

Olof Bryngdahl

Paul H Voisin

David I Cullumber

Adrianus H Oudenhuysen

The present laser/detector hybrid with a turning mirror integrated into the photo detector chip. This allows a smaller package for the device and a simpler method for producing the laser/detector device. The laser beam is emitted along the surface of the chip towards a groove cut in the chip. A mirror is mounted in the groove, and the mirror has a corrugated structure so that it will reflect the beam and convert it into multiple beams at the same time.

Laser/detector hybrid with integrated mirror and diffracted returned beam

A wavelength sensitive hologram which combines the 780 nm laser beam and the 650 nm laser beam to produce a compact DVD optical pickup. The 780 nm laser beam is incident on the hologram at an angle so that the first order diffraction from the hologram propagates along the optical axis of the hologram. The wavefront recorded on the hologram also contains aberration correction components so that the focused 780 nm laser beam on the CD substrate is nearly perfect or at least diffraction limited. The 650 nm laser beam is incident normal to the hologram plane so that the 0 order diffraction of the 650 nm laser beam remains propagating along the optical axis of the hologram.

Wavelength sensitive beam combiner with aberration correction

An optical sensor consisting of a nearly monochromatic point source such as a light emitting diode (LED) or a vertical cavity surface emitting laser (VCSEL) which is mounted on a multiple element detector. When this sensor is placed near a moving object with a reflective periodic pattern on its surface (such as an optical disk), it can produce a signal which can be used to control the position of the object. Unlike other sensors which often use lenses to project the light emitted by the light source onto the object and collect the light reflected from the object and project them onto a photodector, this new sensor performs the tasks of object illumination and light collection without the use of any optical component. A self-imaging principle is used by placing the detector on the self-imaging plare of the object to detect the motion of the object. In order to detect the periodic signal in the self-image of the periodic object, the detector element is covered with a grating structure having the same period or two times the period of the object.

Optical track sensing device

Multiple element laser diode assembly incorporating a cylindrical microlens and at least one of an astigmatism correcting element and a collimating element. The use of a single purpose cylindrical microlens, for instance for circularizing a beam of laser light output from said diode, in operative combination with at least one additional optical element for correcting astigmatism and for collimating the beam enables the passive mounting of the several optical elements of the assembly without an active alignment step. The cylindrical microlens may incorporate as single powered surface, as may the astigmatism correction element. Alternatively, the astigmatism correction element may comprise a tilted optical plate. The collimating lens may be a spherical lens.

Multiple element laser diode assembly incorporating a cylindrical

The present invention provides a semiconductor laser and a photodector on a supporting substrate. The supporting substrate is inserted into a housing with a 45 degree mirror for the purpose of redirecting the light emitting through the edge of the laser to propagate along the optical axis of the hybrid device. A hologram lens is mounted at the output end of the hybrid device to diffract the returned beam to the photosensitive ares of the detector without returning through the mirror.

Laser/detector hybrid with mirror source and diffracted return beam

A method for packaging a hybrid device which has a semiconductor laser diode and photodetectors. The laser diode is mounted on a silicon chip (a 'silicon submount') containing a photodetector for monitoring the laser power. An array of silicon submounts are mounted on a heat-sink plate which consists of a heat-sink substrate covered with a metal layer. The metal layer is cut in multiple places down to the heat-sink substrate to form multiple conductive strips. The heat-sink plate with the silicon submounts is then covered with a heat-sink cover plate which has identations formed to provide cavities for the silicon submounts. In addition, cavities are provided to allow connections to the conducting metal strips. The combined assembly is then sliced into bars exposing an opening for the laser diode and openings for connections to the conductive strips. The bars are turned on their sides and laminated to a glass substrate to form a front window for the laser diode assembly. The bar is then cut into separate pieces, each having a single laser diode. A photodetector may be mounted on the front of the glass window before or after the bar is cut into pieces.

Packaging method for semiconductor laser/detector devices

A compact hybrid laser and photodetector device is disclosed. A heat sink and a metal layer are bonded together, and then mounted on a circuit board. A semiconductor laser chip is mounted on the metal layer. The edge of the metal layer serves as a bonding pad for a wire connection to a bonding pad on the circuit board. A rear-facet photodetector is mounted on the circuit board beneath the semiconductor laser chip. A multiple element photodetector is also mounted on the circuit board for detecting a signal reflected off a media. Preferably, the rear facet and multiple element photodetectors are a single integrated circuit.

Hybrid optical pickup with integrated power emission and reading

An improved optical head for reading information recorded on a reflected medium. The optical head uses a hologram lens assembly having a transparent plate and a hologram lens, the transparent plate being obliquely positioned relative to a forward and a return beam paths. The transparent plate corrects beam aberrations in a laser beam emitted by a semiconductor laser on the forward beam path. The hologram lens diffracts the laser beam on the return beam path onto a photodetector. Both the transparent plate and the hologram lens add beam aberrations to the defracted laser beam on the return beam path for tracking purposes. The hologram lens assembly may also include a second hologram lens, preferably a three beam diffraction grating, for tracking purposes. The hologram lens and the diffraction grating may be located on the obliquely positioned transparent plate or on other transparent plates.

Semiconductor laser optical head assembly

A semiconductor laser assembly is provided with a photodetector module and a laser module mounted on orthogonal surfaces of a heatsink. The photodetector module includes a photodetector and two electrically isolated wire bond blocks, each with two surfaces parallel to the orthogonal surfaces of the heatsink. The laser module includes a laser diode bonded and a wire bond region with two surfaces also parallel to the orthogonal surfaces of the heatsink. Both of the wire bond block surfaces of the photodetector modules are thus parallel to the wire bond region surfaces on the laser module, allowing wire connections to be made between parallel surfaces before the heat sink is mounted on a header. One of the surfaces of each of the wire bond blocks and regions is parallel to the pins of a header, allowing attachment of wires from the photodetector module and the laser module to the pins without rotating the header and pins.

Semiconductor laser assembly

An actuator for an objective lens in an optical head which provides a compact structure that does not move the laser beam relative to the objective lens in the tracking mode. The low profile optical head design is accomplished by designing the optical beam path in the same space occupied by the tracking and focusing motor. A mirror reflects a laser beam from a laser at an angle to an objective lens. The objective lens and the mirror are coupled together in a manner allowing movement of the objective lens relative to the mirror along the path of a laser beam from the mirror to the objective lens. The objective lens, mirror and the coupling mechanism are all moved along the path of the laser beam between laser and the mirror for tracking control. Because the mirror moves with the objective lens, there is no beam clipping or beam distortion. For focusing, the objective lens is moved relative to the mirror. The laser, the detector and their associated optics are stationary, with only the mirror and objective lens being moved, thus limiting the mass moved and the power requirements. The simple structure eliminates the need for a fiber optic cable.

Tracking and focus actuator for a holographic optical head

Method and apparatus useful in monitoring and adjusting focus and tracking of a read/write beam in a data disk-storage system are provided. In one embodiment, the reflected beam is split into a plus first order, astigmatically focused first beam and a minus first order astigmatically focused second beam. The two beams produce images which change in a mirror symmetric fashion in response to changes in the focus or tracking but in a parallel fashion in response to changes in the optical axis. Signals from detectors of the two beams are combined to negate the influence of optical axis movement or other optical faults. In another embodiment, a beam reflected from the disk is split into a first beam converging on an image plane and a second beam defocused at the image plane. The second beam has a relatively large diameter at the image plane and is relatively insensitive to optical axis deviations. Phase relationships of the second beam are used to determine if the beam impinging of the disk is focused. By combining signals from the first and second beams, the resultant signal is insensitive to optical axis errors and indicates the magnitude and direction of focus correction needed. The second beam is also used in monitoring or measuring tracking of the read/write beam. In both embodiments, the beam splitting is preferably produced by a zone plate.

Method and apparatus for focus and tracking in an optical disk system

A magneto-optical head using a laser source unit with a focus error and a tracking error detector in substantially the same optical path as the originating laser beam. In this invention the stored information is derived from the beam reflected by a beam-splitter, while the transmitted light is utilized for generating the tracking error and the focus error signals.

Magneto-optical head with separate optical paths for error and data

The present invention is a combined surface emitting semiconductor laser and photodetector in a single housing with the photodetector positioned to detect light emitted from the surface emitting laser and reflected off of a medium. The surface emitting laser is mounted on the top surface of a chip which includes at least one set of two photodetectors for detecting a reflected beam. At least two photodetectors are used so that spacial variations in the reflected beam can be detected for focusing and tracking when the device is used in an optical head. Photodetectors are arranged to intersect a diffracted beam from a hologram lens used in an optical head. A rear emission photodetector for monitoring the power of the surface emitting laser is positioned so that it will not receive diffracted light which will interfere with its operation.

Hybrid surface emitting laser and detector

A method for constructing an optical head having a holographic diffraction grating for focusing a light beam on a photodetector is disclosed. The photodetector is first mounted in the optical head and the distance between the position where the hologram lens will be placed and the photodetector is measured. The holographic grating pattern which is etched onto the hologram leans is then created so that it will focus the laser beam at the measured distance. The hologram lens is then mounted in the optical head.

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Cupertino, CA, United States of America

Wai-Hon Lee