Abstract: Optical systems of the present invention include amplifiers configured to achieve maximum signal channel in a span downstream of the transmitter and amplifier site and to decrease the interaction between the wavelengths at high signal channel powers. In addition, the system can include various types of optical fiber positioned in the network to provide for increased signal channel powers and higher gain efficiencies in the system.

Abstract: Optical systems of the present invention include amplifiers configured to achieve maximum signal channel in a span downstream of the transmitter and amplifier site and to decrease the interaction between the wavelengths at high signal channel powers. In addition, the system can include various types of optical fiber positioned in the network to provide for increased signal channel powers and higher gain efficiencies in the system.

Abstract: Apparatuses, methods, and systems are disclosed that provide for simultaneously upconverting electrical signals carrying information at electric frequencies onto optical subcarrier lightwave frequencies that are greater and less than the carrier frequency of the lightwave onto which the electrical frequencies were upconverted. The upconversion of the electrical signals can be performed with or without suppression of the optical carrier frequency.

Abstract: Apparatuses, methods, and systems are disclosed that provide for simultaneously upconverting electrical signals carrying information at electric frequencies onto optical subcarrier lightwave frequencies that are greater and less than the carrier frequency of the lightwave onto which the electrical frequencies were upconverted. The upconversion of the electrical signals can be performed with or without suppression of the optical carrier frequency.

Abstract: Apparatuses, methods, and systems are disclosed for controlling optical signal wavelength spacing by providing for simultaneous upconversion of a plurality of electrical signal on subcarrier frequencies of an optical carrier frequency with or without modulation of an electrical data signal onto the optical carrier frequency. The optical carrier lightwave is split into a plurality of split lightwaves upon which one or more electrical frequencies carrying information can be upconverted onto optical subcarriers of the lightwave carrier frequency. The relative spacings of the optical subcarrier lightwaves will thus be unaffected by variation in the carrier frequency. The optical subcarrier lightwaves can then be recombined to form the optical data signal carrying the plurality of information carried by the electrical frequencies.

Abstract: Apparatuses, methods, and systems are disclosed that provide for simultaneously upconverting electrical signals carrying information at electric frequencies onto optical subcarrier lightwave frequencies that are greater and less than the carrier frequency of the lightwave onto which the electrical frequencies were upconverted. The upconversion of the electrical signals can be performed with or without suppression of the optical carrier frequency.

Abstract: An photodetector circuit comprising an avalanche photodiode having a signal input for receiving an input optical signal to be converted to an electrical signal. The photodetector circuit further includes biasing circuitry, coupled to the avalanche photodiode, for applying a bias voltage to the avalanche diode. The bias circuitry includes: (1) a dc bias circuit for providing a dc component to the bias voltage for maintaining the avalanche diode in a stable avalanche gain condition when receiving the input optical signal; and (2) a modulating circuit for providing a high frequency modulating component to the bias voltage for modulating the bias voltage in a manner that enhances the operational characteristics of the avalanche photodiode. In particular, the modulating component to the bias voltage decrease the noise of the signal output of the avalanche photodiode for a given average gain, and increases the bandwidth of the signal output of the avalanche photodiode for a given average gain.

Abstract: The present disclosure illustrates that the process of summing an amplitude limited PSK (phase-shift keyed) signal with a one data bit delayed version of that signal and envelope detecting the sum will produce a digital binary data stream that is representative of the original data used to produce the PSK signal in the first place. This approach is distinguished over the prior art approach in that the PSK signal is limited to an amplitude value which is less than the minimum value produced by vectorial summation of noise with the transmitted PSK signal for optimal bit error rate performance.

Abstract: In a radio receiver a multipath fade compensating circuit comprises a single-pole filter circuit the center frequency and Q of which are controlled in dependence upon the amplitudes of signal components in narrow frequency bands within the band of frequencies passed by the filter circuit. The narrow bands may be selected from an array by a microprocessor, or may be derived using variable frequency filters.