Abstract: The present invention utilizes a high-speed serial data transceiver to generate two high-speed electric pulse signals. After passing through a gain network, the signals are used for driving an electro-optic phase modulator (PM) so as to realize phase modulation of photon signals. The present invention may directly use a high-speed digital signal to realize a four-phase modulation function needed by the BB84 quantum key distribution protocol without using a digital to analog converter or an analog switch. This can prevent modulation rate from being restricted by links including digital-to-analog conversion, switching of the analog and the like. A dual-electrode electro-optic phase modulator scheme can also effectively reduce requirements for amplitude of a modulation driving signal, thus facilitating realization of high-speed phase modulation, which meets requirements of quantum key distribution.

Abstract: The present invention utilizes a high-speed serial data transceiver to generate two high-speed electric pulse signals. After passing through a gain network, the signals are used for driving an electro-optic phase modulator (PM) so as to realize phase modulation of photon signals. The present invention may directly use a high-speed digital signal to realize a four-phase modulation function needed by the BB84 quantum key distribution protocol without using a digital to analog converter or an analog switch. This can prevent modulation rate from being restricted by links including digital-to-analogue conversion, switching of the analogue and the like. A dual-electrode electro-optic phase modulator scheme can also effectively reduce requirements for amplitude of a modulation driving signal, thus facilitating realization of high-speed phase modulation, which meets requirements of quantum key distribution.

Abstract: An input device encodes motion using a laser self-mixing velocimeter. The laser beam is directed at a disk or other moving member. As light from that beam is reflected back into the emitting cavity of the laser, the beam power output fluctuates because of the self-mixing effect and generates a beat signal. The beat signal frequency is used to determine the speed of the member's motion. The direction of motion is also determined based on the beat signal. A difference frequency analog phase locked loop filters the beat signal. A zero-point control disables motion detection when the average beat signal amplitude falls below a threshold. A triangle modulator generates a triangle wave for the laser bias current, with the triangle wave frequency being a submultiple of the beat signal frequency.

Abstract: Optical tracking systems, method, and devices are described in which optical components detect light within a substantially planar region adjacent to a user device. Tracking logic may receive signals output by the optical components and determine coordinates associated with a movement of a pointing object through the substantially planar region. The tracking logic may then provide for translation of the coordinates into an action on a display, such as, for example, a movement of a cursor or other icon on the display.

Abstract: A laser range finder includes a laser and a photosensitive element. The laser projects a beam onto a target surface. A backscattered portion of the laser beam returns to the laser from the target surface and enters the laser emitting cavity. Variations in laser output power are detected by the photosensitive element, which provides a “beat” signal to a frequency detection circuit. The frequency detection circuit includes a difference frequency analog phase locked loop (DFAPLL) providing a purified form of the beat signal. The frequency of the purified beat signal is determined and used to calculate distance to the target surface.

Abstract: Optical tracking systems, method, and devices are described in which optical components detect light within a substantially planar region adjacent to a user device. Tracking logic may receive signals output by the optical components and determine coordinates associated with a movement of a pointing object through the substantially planar region. The tracking logic may then provide for translation of the coordinates into an action on a display, such as, for example, a movement of a cursor or other icon on the display.

Abstract: A laser range finder includes a laser and a photosensitive element. The laser projects a beam onto a target surface. A backscattered portion of the laser beam returns to the laser from the target surface and enters the laser emitting cavity. Variations in laser output power are detected by the photosensitive element, which provides a “beat” signal to a frequency detection circuit. The frequency detection circuit includes a difference frequency analog phase locked loop (DFAPLL) providing a purified form of the beat signal. The frequency of the purified beat signal is determined and used to calculate distance to the target surface.