| Patent application number | Description | Published |
|---|
| 20080205246 | OPTICAL HEAD AND OPTICAL DISK DEVICE - An interference type optical head and an optical disk device that can easily adjust an optical path length difference of a couple of lights, ensure higher signal amplification effect, and are suitable for reduction in size are provided in order to improve a regeneration signal quality with amplification of signal in the case where reflectivity of each layer must be lowered and relative noise for the signal increases because read speed is high in a multilayer optical disk. In view of essentially improving an S/N ratio of the regeneration signal in high-speed rotation of a multilayer disk, a plurality of interference phases are generated and an optical system for differential calculation has been reduced in size with an angular selective polarization conversion element in the optical disk device for amplifying the signal with interference of the light not radiated to the disk with the reflected light from the disk. Moreover, adjustment of reflection mirror angle of the reference light is no longer required by using a corner cube prism as the reference light reflection mirror and highly accurate signal detection can also be realized with a simplified structure. | 08-28-2008 |
| 20090257327 | Optical Signal Detecting Circuit and Information Reproducing Device Using the Same - An object of the present invention is to achieve both low noise and fast response in an optical signal detecting circuit capable of providing all of three signals—a focus error signal, a tracking error signal, and an RF signal—with only a single detection system. A single current-to-voltage converter converts a current signal obtained by adding currents flowing through two photodiodes, into a voltage signal. Not only currents flowing into the photodiodes, but also currents flowing out from the photodiodes are taken out as the voltage signals. Moreover, by applying two different reference voltages to the current-to-voltage converters, a reverse bias voltage is applied between the terminals of each photodiode. | 10-15-2009 |
| 20090316539 | OPTICAL HEAD AND OPTICAL DISK APPARATUS - There are provided an interference type optical head and an optical disk apparatus, which have a signal amplification effect and which can be manufactured in sizes comparable to conventional optical heads. In an optical disk apparatus that performs signal amplification by making a light, which is used as a reference light without being irradiated on an optical disk and, interfere with reflected light from the optical disk, a corner cube prism that reflects the reference light is mounted on the same actuator as an objective lens. Further, there is provided a movable portion that adjusts the optical path length of the interfering light in accordance with the kind of optical disk being read and the recording layer being read. A wedge prism may be used for the movable portion, and a spherical aberration correction lens and an optical path length adjusting component may be moved integrally. Thus, a stable amplification effect may be obtained while keeping the overall size comparable to conventional apparatuses. | 12-24-2009 |
| 20100329667 | INTERFEROMETER, DEMODULATOR, AND OPTICAL FIBER COMMUNICATION MODULE - In a delay line interferometer inside a demodulator, with respect to polarization states of two split beams of light to be interfered with each other, p polarization and s polarization are reversed by a half beam splitter and, further, again multiplexed by the half beam splitter used for splitting so that interference beams of light are generated. | 12-30-2010 |
| 20110080815 | OPTICAL RECORDING AND REGENERATING APPARATUS - The present invention achieves an optical recording and regenerating apparatus focusing two opposed beams of light at a same place in an optical recording medium to record a standing wave generated by interference of the two beams of light. In the apparatus, phase information is recorded in the optical recording medium by a phase modulating means for modulating phase of one of the two beams of light. The generation reference light generated from a light source is allowed to interfere with regenerated light generated by projecting one of the two beams of light onto the optical recording medium to generate three or more beams of interfering light having different interference phases are simultaneously generated. The three or more beams of interfering light are then detected, and the phase modulated by the phase modulating means is demodulated from an output of the detector. | 04-07-2011 |
| 20110085238 | OPTICAL ELEMENT AND OPTICAL APPARATUS - The present invention provides a small and inexpensive optical element that integrates a reflecting mirror and a wave plate function. A reflecting wave plate is configured by arranging a periodic metal comb-like structure whose pitch is equal to or below a wavelength and a mirror structure with a distance equal to or below a coherence length. | 04-14-2011 |
| 20110141867 | OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS AND OPTICAL INFORMATION REPRODUCING APPARATUS - In a system of detecting an interference light with a light not irradiated onto an optical disc to increase the S/N ratio, it is difficult to stably acquire a reproduced signal with a simple configuration. Since the recording density is not improved, an improvement in transfer rate is difficult. In an optical information recording/reproducing apparatus where two optical beams face each other and are focused at the same place of a recording medium to record a standing wave developed by interference of the two optical beams, a phase difference of the two optical beams is modulated in a multiple stage and recorded. During reproduction, an interference light of a reproduced light from the recording medium and another reproduction reference light is detected as a reproduced signal, and a phase servo control stabilizing the phase of interference during reproduction by using a low frequency component of the reproduced signal is conducted. | 06-16-2011 |
| 20110188850 | INTERFEROMETER, DEMODULATOR, AND OPTICAL COMMUNICATION MODULE - When designing a demodulator for a DPSK-modulated signal, it is required that optical phase modulation is performed fast and the demodulator has a long lifetime. To achieve this object, a delay line interferometer inside the demodulator performs adjustment of phase difference between two split lights caused to interfere, using a first optical phase modulation unit such as a Piezo actuator and a second optical phase modulation unit such as a heating element that operates slower in modulation speed than the first optical phase modulation unit and is slower in deterioration speed. | 08-04-2011 |
