Abstract: An optical pickup head is provided, including a laser diode set, an optical element set and an optical signal detector. The laser diode set is a laser light source capable of emitting single wavelength, two wavelengths or three wavelengths laser lights. Optical element set includes a low reflectivity beam-splitter and an objective lens. The low reflectivity beam-splitter has an average reflectivity ranging from 10% to 30%. After reflected twice by low reflectivity beam-splitter, the light fed back from recording medium to the laser diode set is reduced to avoid laser noise problem. Moreover, with the optical signal detector having a tilt ? ranging from 3° to 15° to optical axis, the optical signal detector can directly reflect the incident laser light into a different direction so that the reflected light will reduce the feedback light to the laser diode set.

Abstract: An optical pickup with a reflective coating device is provided, including a laser diode (LD), an optical element, and a photo detector integrated circuit (PDIC). The LD emits 1-3 lights with different wavelengths but the same polarization orientation. The beam transmits through the optical element set and focus on a recording media for data reading and writing. The beams are reflected by the recording media, through the optical element set, and detected by the PDIC for signal detection. The optical element set further includes a grating, a reflective coating device, and an objective lens. By using the reflective coating device to change the linear polarization orientation of the emitting light and the feedback light for 90° angle, the relative intensity noise caused by the feedback light in LD can be reduced.

Abstract: An optical pick with a reflective coating device is provided, including a laser diode (LD), an optical element, and a photo detector integrated circuit (PDIC). The LD emits 1-3 lights with different wavelengths but the same polarization orientation. The beam transmits the optical element set and focus on a recording media for data reading and writing. The beams are reflected by the recording media, through the optical element set, and detected by the PDIC for signal detection. The optical element set further includes a grating, a reflective coating device, and an objective lens. By using the reflective coating device to change the linear polarization orientation of the emitting light and the feedback light for 90° angle, the relative intensity noise caused by the feedback light in LD can be reduced.

Abstract: The present invention relates to an optical device which includes a first laser diode, a beam splitter, a first objective lens, a photo-detector, a second laser diode, a wedged plate beam splitter, a second objective lens and a collimator. The present invention deploys two independent transmitting paths. The retrieving paths share the beam splitter and the photo-detector commonly at the returning route.

Abstract: An alignment apparatus in an optical pickup device is provided. It comprises a laser diode, a first coupling carrier, an optical assembly, a signal detector, a record medium and a second coupling carrier. The first coupling carrier bears the laser diode while the second coupling carrier bears the optical assembly and the signal detector. The first coupling carrier has a coupling structure of a spherical curved surface. The second coupling carrier has a coupling structure of a curved surface or a plane tangential to the spherical curved surface of the first coupling carrier. The first and the second coupling carriers couple each other. The inclination angles with respect to two-axes and the polarization direction of the laser beam are adjusted by rotating the coupling structure of the spherical curved surface, which significantly reduces the time interval of calibration optimization of searching laser beam and also reaches the goal of optimization of light energy characteristics of the laser beam.

Abstract: The present invention relates to an optical device which includes a first laser diode, a beam splitter, a first objective lens, a photo-detector, a second laser diode, a wedged plate beam splitter, a second objective lens and a collimator. The present invention deploys two independent transmitting paths. The retrieving paths share the beam splitter and the photo-detector commonly at the returning route.

Abstract: A focus/tracking method and system is provided for use in an optical drive with a possibly multiple-wavelength laser source for control of the focus/tracking of the pickup head of the optical drive. The use of a multiple-wavelength laser source allows the optical drive to read data from various types of optical discs. The focus/tracking method and system combines the use of a differential, dual optical channel method for focusing control of the laser beam used to read data from the optical disc and the use of the single-beam tracking method for tracking control of the same. The focus error signal and the tracking error signal can be obtained from the same set of multi-element photodetectors. The structure of the system can therefore be simplified to include a reduced number of constituent components thus allowing a reduction in manufacturing cost.

Abstract: A focus/tracking method and system is provided for use in an optical drive with a possibly multiple-wavelength laser source for control of the focus/tracking of the pickup head of the optical drive. The use of a multiple-wavelength laser source allows the optical drive to read data from various types of optical discs. The focus/tracking method and system combines the use of a differential, dual optical channel method for focusing control of the laser beam used to read data from the optical disc and the use of the single-beam tracking method for tracking control of the same. The focus error signal and the tracking error signal can be obtained from the same set of multi-element photodetectors. The structure of the system can therefore be simplified to include a reduced number of constituent components, thus allowing a reduction in manufacturing cost.

Abstract: A dual-wavelength holographic laser module is provided. The dual-wavelength holographic laser module includes a holographic optical element (HOE), a multiple-element photodetector, and a laser light source that can produce a laser light with a wavelength that has, for example, two desired quantities. The laser light emitted from the laser light source with a desired wavelength can travel through the HOE and an objective lens unit, which is used to focus the laser light onto an optical disk of the DVD system, the CD system, or the CD-R system, depending on which wavelength quantity is chosen. The objective lens unit includes a single lens with a changeable NA quantity or a two-lens system that can be switched to put one lens at a time in the optical path. The optical disk reflects the laser light back to the HOE along the same light path. The reflected laser light is diffracted by the HOE to reach to the multiple-element photodetector.

Abstract: A two-wavelength laser diode package is provided, which can be utilized in the read/write head of an optical drive capable of reading data from different types of optical discs, such as CD (compact disc), CD-R (CD Recordable) and DVD (digital versatile disc). The laser diode package includes a pair of laser diodes of two different specifications in wavelength, which are disposed on one or two submounts, either horizontally or vertically oriented with each other. Further, a beam coinciding means, such as a micro dichroic prism, a micro dichroic plate, a micro dichroic beam-splitter, or an external dichroic beam-splitter, is used to make the two respective laser beams from the two laser diodes to propagate on the same propagation axis when in use.