Industrial Technology Research Institute

Tzu-Ping Yang

Der-Ray Huang

Mark O Freeman

Hsi-Fu Shih

Jau-Jiu Ju

Hung-Lu Chang

Jinn-Kang Wang

Carl Y Yang

Wei-Chih Lu

A bifocal optical pickup head is disclosed for use in a optical pickup apparatus having a single objective lens, for generating two different focuses (bifocus) to access a compact disc (CD) and a digital versatile disc (DVD), which the thickness is different. When a beam passes through an optical element disclosed in the present invention, numerical aperture is controlled and spherical aberration is reduced by the optical element due to variations in optical path and radius. Therefore, after beams having different numerical apertures are focused by an objective lens, various focuses can be obtained.

Bifocal optical pickup head

The present invention discloses a multiple-beam holographic optical pick-up head, which has the advantages of the multiple-beam optical pick-up head and the holographic optical pick-up head and can increase the light usage efficiency. This invention uses the property that a polarized diffractive optical element can generate different optical effects for laser beam with different polarizations and places a polarized multiple-beam grating and polarized hologram on the optical path for splitting the incident light toward the disc into multiple reading beams by the multiple-beam grating. The returning laser beams reflected from the disc are diffracted and diverted by the hologram to reach a photodetector. Both the incident and reflective beams are diffracted once only; thus the light usage efficiency can be increased.

Multiple-beam holographic optical pick-up head

The invention is directed to a sieving apparatus for a bio-chip, which has a light source, a HOE unit, a splitter, an objective lens, a filter, and an optical signal sensor. The HOE unit is coupled with a light source, so as to diffract the light into a zeroth order beam and a first order beam. The zeroth order beam has no deflection but the first order beam has a deflection from the zeroth order beam. The splitter is coupled to the HOE unit, so as to lead the two beams to the objective lens, which further leads the two beams to the bio-chip, in which the first order beam is incident onto the bio-chip from an incident angle, causing a florescent light from the sample. The bio-chip also reflects the zeroth order beam. Both the reflected zeroth order beam and the fluorescent light travel through the objective lens and the splitter. The filter is coupled to the splitter, so that an undesired portion of the light beams incident on the splitter is filtered. The optical sensor receives the light beams after the filter. The zeroth order beam is used to generate a focusing signal and a tracking signal. The focussing signal and the tracking signal are used to control the servo, so as to align the optical sensor to the samples for detecting the florescent light. Alternatively, the sensor can be fixed but the bio-chip is shifted by the servo system.

Sieving apparatus for a bio-chip

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. The photodetector receives the reflected laser light to obtain a signal, which is used for focusing and tracking, and further reads the information in the DVD system, the CD system, or the CD-R system. The laser light has a single light path even though the laser light can have two different wavelength quantities.

Dual-wavelength optical pickup head

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.

Two-wavelength semiconductor laser diode package for use on the read/write head of an optical drive capable of reading different types of optical discs

Growing community of inventors

Taipei, Taiwan

Tzu-Ping Yang