Abstract: An optical track sensing device, and in particular to an optical sensor for detecting optical tracking information on a moving medium (or stationary medium and moving sensor). The sensing device relies on self-imaging, rather than optics, and obtains a very acceptable detected signal at other than the self imaging plane of the reflection off a moving medium. This provides more flexibility in the placement of the sensor, while still allowing the elimination of optical components by relying on self-imaging instead. In addition, by providing a pattern over the photodetector with a smaller period, higher frequency harmonics are detected, allowing more precise detection of the position of the medium. In one embodiment, the period of the detector pattern is selected to detect the higher harmonics of the grating on the moving medium.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.