Abstract: An accessory that is attachable to a device comprises an image sensor and a beam splitter having a first surface and a second surface. The beam splitter is configured to impinge light upon the first surface, and split the light impinging upon the first surface into at least a first beam, a second beam, and a third beam. The first beam travels from a first opening of the device to a second opening of the device along an optical path when the accessory is attached to the device, the second beam travels from the first surface to the image sensor, and the third beam travels from the second surface to the image sensor or a beam dump.

Abstract: An apparatus and method are described for combining optical amplification and dispersion compensation in a Raman amplifier. A Dispersion-Managing Raman Amplifier (DMRA) combines Raman amplification with dispersion compensation by selecting the length and dispersion of the gain fiber to balance the dispersion of the link. This gain fiber is also single-mode at the signal and pump wavelengths. The pumping level is adjusted to balance the losses from the gain fiber and transmission link, while the pumping configuration is selected to remain within the 3 dB loss length for the pumping light. When the amplifier is split into two segments, the two segments may be joined by an isolator, a gain equalization element, and/or an optical add/drop multiplexer. For WDM transmission systems based on dispersion-shifted fiber (DSF), operation in the “violet band” between 1430–1530 nm is based on Raman amplification. By using a DMRA, a dispersion and nonlinearity managed system can be implemented.

Abstract: Switched video broadband service and narrowband telecommunications service are integrated and provided directly to subscribers. A plurality of video channels are provided to a central office by a video service provider, and said video channels are transmitted to a remote terminal using standard FM video supertrunks. At the remote terminal, video channels selected by a group of subscribers are frequency-division multiplexed with baseband signals of narrowband telecommunications service and are transmitted over a single fiber to an optical network unit adjacent the living units of the group of subscribers. The subscriber selected channels are then demultiplexed and provided to the living units via coaxial drops, along with the narrowband telephone service provided on twisted pairs. Channel requests from the group of subscribers are combined and transmitted upstream in a single narrowband video control channel.

Abstract: Constant light output is provided by a laser diode over various temperatures or operating points by adjusting the bias current in accordance with a midpoint of a detected peak and a detected valley of an output power level and adjusting the modulation current amplitude in accordance with the difference between the detected peak and the detected valley output power.

Abstract: Constant light output is provided by a laser diode over various temperatures or operating points by adjusting the bias current in accordance with a midpoint of a detected peak and a detected valley of an output power level and adjusting the modulation current amplitude in accordance with the difference between the detected peak and the detected valley output power.