Exemplary methods and apparatus may provide optical gates and optical switches using such optical gates. Each optical gate may include a semiconductor optical amplifier that is placed in a substrate. The semiconductor optical amplifier may be coupled to input and output couplers to receive and selectively output optical signals into and out of the substrate.

Consistent with the present disclosure, an optical switch is provided that switches multiple wavelength division multiplexed (WDM) optical signals. Each of the WDM signals includes optical signals having the same wavelengths. The WDM signals are supplied to optical splitters, which supply power split portions of the WDM signals to corresponding optical gates. Groups of the optical gates are associated with a corresponding switching block, which may include a cyclical arrayed waveguide grating (AWG), and the optical gates within each group are controlled so that one gate passes a received WDM signal portion while the remaining optical gates in the group are in a blocking configuration. As a result, the WDM portion received by the non-blocking gate is demultiplexed in the switching block and each of the wavelength components that constitute the selected WDM portion are supplied to corresponding outputs within the switching block. In a later time interval, a different optical gate may be rendered non-blocking so that a different WDM signal portion, supplied from a different optical splitter and carrying different information over the same wavelengths, may be input to the switching block. Thus, by controlling the optical gates, different WDM signal portions may be switched to, and thus demultiplexed by, a particular switching block. In addition, portions of the same WDM signal may be selectively supplied to different AWGs by appropriately control of the optical gates.

Split cascade circuits include multiple cascade paths coupled between voltage supply rails. Each cascade path includes a pair of controllable switches. A feedback path is provided for at least one of the cascade circuit paths. An active load circuit may also have a split cascade structure. Multiple-stage circuits, for implementation in Trans-Impedance Amplifiers (TIAs) or analog Receive Front-End modules (RXFEs), for example, include multiple stages of split cascade circuits.

This disclosure describes C and L band optical communications module link extender, and related systems and methods. An example method may include receiving, by a first dense wave division multiplexer (DWDM) of an amplification module in communication with an optical communication module link extender (OCML), first passive optical network (PON) signals in a downstream direction. The example method may also include combining the first PON signals into a combined PON signal, and outputting the combined PON signal to the OCML. The example method may also include receiving, by a first input of the OCML, the combined PON signal. The example method may also include receiving by a second dense wave division multiplexer (DWDM) of the OCML, one or more optical data signals in the downstream direction, the one or more optical data signals being a different signal type than the one or more PON signals. The example method may also include combining, by the second DWDM, the one or more optical data signals into a combined optical data signal, and outputting the combined optical data signal. The example method may also include outputting, by the OCML, the combined optical data signal and the combined PON signal. The example method may also include receiving, from the amplification module and from the OCML, a second combined PON signal in an upstream direction at one or more Raman pumps of the amplification module. The example method may also include outputting, by the one or more Raman pumps, the second combined PON signal to the first DWDM.

This disclosure describes, among other things, an Optical Communications Module Link Extender (OCML) including embedded Ethernet and PON amplification rather than relying on a separate amplification module for Ethernet and/or PON signals transmitted through the OCML. Providing an OCML that is able to provide the appropriate amplification to transmit both Ethernet and PON signals may be accomplished by using one or more Raman pumps on the signals transmitted in the upstream direction through the OCML (for example, upstream from one or more customer devices to one or more OLTs for PON signals. This OCML configuration may allow for a more cost-effective and efficient system with a smaller footprint than a system that relies on external amplification modules to transmit Ethernet or PON signals.

This disclosure describes, among other things, an Optical Communications Module Link Extender (OCML) including embedded Ethernet and PON amplification rather than relying on a separate amplification module for Ethernet and/or PON signals transmitted through the OCML. Providing an OCML that is able to provide the appropriate amplification to transmit both Ethernet and PON signals may be accomplished by using one or more Raman pumps on the signals transmitted in the upstream direction through the OCML (for example, upstream from one or more customer devices to one or more OLTs for PON signals. This OCML configuration may allow for a more cost-effective and efficient system with a smaller footprint than a system that relies on external amplification modules to transmit Ethernet or PON signals.

In order to provide an optical transmission device capable of implementing the spectral control of WDM signals while taking into account optical component characteristics, an optical transmission device is provided with: a WSS; a wavelength monitor that outputs a signal expressing a first spectrum, which is the spectrum of the WSS optical output; an optical processing unit that subjects the WSS optical output to prescribed processing; a temperature monitor that outputs a signal indicating the temperature of an optical processing means; and a control unit that receives the input of the signal expressing the first spectrum and the signal indicating the temperature, and controls the transmission characteristics of the WSS on the basis of the first spectrum and the temperature.

A method (100) is disclosed for filtering an optical signal to generate at least one electrical output. The method comprises receiving an optical signal (110) and directing at least a part of the optical signal through an n×m array of wavelength selective elements (120), the n×m array comprising n parallel groups, each group comprising m coupled wavelength selective elements. The method further comprises photodetecting an output from each of the n groups of coupled wavelength selective elements (130), and electrically selecting at least one of the photodetected outputs (140). Also disclosed are an optical filtering module (200, 300) a controller (400) for an optical filtering module and a computer program.

A receiver and a transmitter are disclosed that are applicable to space, air or ground RF communication systems and are applicable to systems where one or more signals of multiple types and characteristics are present in any given beam such as a communication spot beam on a high-throughput satellite. The transmitter can include an optical frequency comb configured to generate a multitude of equidistantly spaced optical wavelengths; an electro-optic modulator that receives the multitude of equidistantly spaced optical wavelengths and a data signal and produce a modulated optical beam; an optical circulator that receives the modulated optical beam; an optical switch that switches the modulated optical beam to an output port of the optical switch terminated in one or more Fiber-Bragg gratings; a wavelength division multiplexer that receives individual wavelengths of the modulated optical beam that are time-delayed from the optical circulator; and a plurality of antenna elements.

This disclosure describes devices related to multiplexing optical data signals. A system may be disclosed for multiplexing one or more optical data signals. The system may comprise a forty channel dense wave division multiplexer (DWDM) configured combine one or more optical data signals. The system may comprise a booster optical amplifier configured to amplify the combined one or more optical data signals and output a first amplified optical data signal. The system may comprise a variable optical amplifier (VOA) communicatively configured to receive the amplified first optical data signal, adjust the power of the amplified first optical data signal to a first level, and output a second optical data signal. The system may comprise a WDM communicatively coupled to the VOA, the WDM configured to output a combined second optical data signal and one or more third signals to a primary fiber.