Abstract: An optical pickup which is configured to suppress resonances in the objective lens which are caused during tilt control of the objective lens is provided. The optical pickup device includes an objective lens, a lens holder for retaining the objective lens, and an actuator for rotating the lens holder to control tilt of the objective lens. The objective lens is bonded to the lens holder via adhesives applied at a plurality of adhesion positions. The adhesion positions at which the objective lens and the lens holder are bonded are asymmetrical relative to a plane which includes the rotation axis of the lens holder and the optical axis of each objective lens.

Abstract: An optical space transmission module reduces an upper limit of light output based on a safety standard of a laser, reduces light returned to a laser, and is made smaller in size. The optical space transmission module includes a light emitting section which outputs a transmission light, a base section including a reflection section which reflects the transmission light, and a reflection type diffusion section which reflects and converts into a diffused light the reflected light which has been reflected by the reflection section. The reflection section has a function to increase a beam diameter of the transmission light after reflection.

Abstract: A light receiver comprises a Fresnel lens for collecting light signals, and a light receiving element disposed closer to the Fresnel lens than the focal point of the Fresnel lens for receiving the light signals collected by the Fresnel lens. The Fresnel lens comprises a lens surface group having a plurality of lens surfaces, and a back cut surface group having a plurality of back cut surfaces connecting the lens surfaces. The back cut surfaces are inclined with respect to the center axis of the Fresnel lens. Thus, the light receiver has a high light collection efficiency of light signals incident within a certain acceptance angle.

Abstract: An optical transmission apparatus is provided in which high optical output power is secured in an optical transmitter, the fine adjustment of the optical axis is unnecessary, and the propagation range of the optical output signal can be adaptively changed. A diffusing liquid lens includes a first liquid and a second liquid containing a scattering material that scatters light, and the curvature of the boundary surface between the first and the second liquids is changed according to the control voltage applied from a controlling unit. A first optical signal outputted from a light emitting device is diffused in the first liquid, and emitted as a second optical signal having a spread angle corresponding to the curvature of the boundary surface and a substantially uniform radiant intensity distribution.

Abstract: The present invention provides an optical receiving device, in which a portion of an optical signal is deflected for optical axis detection only when the optical axis is misaligned to thereby achieve a high S/N ratio of a received signal. A condensing section 100 condenses a received optical signal. An optical element 110 includes a transmission region 111 and a deflecting region 112, and receives the optical signal, which has been condensed through the condensing section 100. A signal light receiving section 120 receives the transmitted light, which has been transmitted through the transmission region 111. A detection light receiving section 130 receives deflected light, which has been deflected through the deflecting region 112 and performs a photoelectric conversion on the received light to thereby output a detection intensity signal that indicates an intensity of the deflected light.

Abstract: In order to improve a transmission speed of multilevel light transmission, increasing the number of light emitting elements is effective. However, in a method in which light outputs from a plurality of light emitting elements are added, because common mode noise contained in the light outputs is added, deterioration in transmission quality caused by the common mode noise prominently arises. Therefore, a difference between two light outputs is previously assigned to data to be transmitted. Specifically, an optical transmitter 102 converts data Dt to multilevel optical signals OSm1 and OSm2 and transmits the converted multilevel optical signals to an optical receiver 103. The optical receiver 103 restores the data Dt which is previously assigned to a difference between electrical signals ESr1 and ESr2 converted from the multilevel optical signals OSm1 and OSm2.

Abstract: A light receiver comprises a Fresnel lens for collecting light signals, and a light receiving element disposed closer to the Fresnel lens than the focal point of the Fresnel lens for receiving the light signals collected by the Fresnel lens. The Fresnel lens comprises a lens surface group having a plurality of lens surfaces, and a back cut surface group having a plurality of back cut surfaces connecting the lens surfaces. The back cut surfaces are inclined with respect to the center axis of the Fresnel lens. Thus, the light receiver has a high light collection efficiency of light signals incident within a certain acceptance angle.

Abstract: An optical space transmission module is provided, which reduces an upper limit of light output based on safety standard of laser, reduces light returned to a laser, and is made smaller in size. The optical space transmission module comprises a light emitting section 100 which outputs a transmission light, a base section including a reflection section 111 which reflects the transmission light, a reflection type diffusion section 120 which reflects and converts into a diffused light the reflected light which has been reflected by the reflection section 111. The reflection section 111 has a function to increase a beam diameter of the transmission light after reflection.

Abstract: The present invention provides an optical receiving device, in which a portion of an optical signal is deflected for optical axis detection only when the optical axis is misaligned to thereby achieve a high S/N ratio of a received signal. A condensing section 100 condenses a received optical signal. An optical element 110 includes a transmission region 111 and a deflecting region 112, and receives the optical signal, which has been condensed through the condensing section 100. A signal light receiving section 120 receives the transmitted light, which has been transmitted through the transmission region 111. A detection light receiving section 130 receives deflected light, which has been deflected through the deflecting region 112 and performs a photoelectric conversion on the received light to thereby output a detection intensity signal that indicates an intensity of the deflected light.

Abstract: An optical transmission apparatus is provided in which high optical output power is secured in an optical transmitter, the fine adjustment of the optical axis is unnecessary, and the propagation range of the optical output signal can be adaptively changed. A diffusing liquid lens includes a first liquid and a second liquid containing a scattering material that scatters light, and the curvature of the boundary surface between the first and the second liquids is changed according to the control voltage applied from a controlling unit. A first optical signal outputted from a light emitting device is diffused in the first liquid, and emitted as a second optical signal having a spread angle corresponding to the curvature of the boundary surface and a substantially uniform radiant intensity distribution.

Abstract: In order to improve a transmission speed of multilevel light transmission, increasing a number of light emitting elements is effective. However, in a method in which light outputs from a plurality of light emitting elements are added, because common mode noise contained in the light outputs is added, deterioration in transmission quality caused by the common mode noise prominently arises. Therefore, a difference between two light outputs is previously assigned to data to be transmitted. Specifically, an optical transmitter 102 converts data Dt to multilevel optical signals OSm1 and OSm2 and transmits the converted multilevel optical signals to an optical receiver 103. The optical receiver 103 restores the data Dt which is previously assigned to a difference between electrical signals ESr1 and ESr2 converted from the multilevel optical signals OSm1 and OSm2.