Components of an optical communications network are described at a node of the network providing switching from one or more degrees of received optical signal routed to a plurality of receivers. The switch at the node generally includes a passive reconfigurable optical add drop multiplexer (ROADM) having drop or output ports that connector to optical channels leading to optical receivers without optical amplifiers between the ROADM outputs and the receivers. Configurations of the node and corresponding parameters are described that provide for use of lower cost components due to the absence of an array of optical amplifiers connected to the ROADM outputs.

Systems and methods for automatically managing the bandwidth requirements of application workloads may include learning the bandwidth requirements using historical data, predicting the required bandwidth for a time interval and provisions the services to deliver the appropriate bandwidth to the applications. Systems and methods for automatically managing the bandwidth requirements of application workloads may also include monitoring for the actual bandwidth requirements of the applications and adapt dynamically to changing requirements.

An optical submarine branching apparatus includes a first, second, and third switching unit. The first switching unit is connected to N first, second, and third optical fiber transmission lines connected to a first, second and third terminal stations, respectively, and switches a transmission route for a wavelength-multiplexed optical signal. The second switching unit is interposed on the N first optical fiber transmission lines between the first terminal station and the first switching unit, and switches a connection relation between in front of and behind a place where the second switching unit is interposed. The third switching unit is interposed on the N second optical fiber transmission lines between the second terminal station and the first switching unit, and switches a connection relation between in front of and behind a place where the third switching unit is interposed.

Embodiments of the present application provide a submarine optical cable system for reducing the complexity of the submarine optical cable system. The submarine optical cable system comprises a first trunk station, a second trunk station, a branch station, first XC equipment, second OXC equipment, a trunk fiber set and a branch fiber. The trunk fiber set at least comprises a first trunk fiber and a second trunk fiber. The branch station is connected with the second trunk fiber arranged between the first OXC equipment and the second OXC equipment through the branch fiber. The first trunk station is configured for sending a first service through a first transmission channel in a first transmission channel set and sending a second service through a second transmission channel in a second transmission channel set. The first OXC equipment is configured for transferring the first transmission channel to the second trunk fiber. The branch station is configured for uploading or downloading the first service and the second service through the second trunk fiber. The second OXC equipment is configured for transferring the transferred first transmission channel to the first trunk fiber.

A method for data transport that includes providing a branch terminal between a first and second trunk terminal, wherein a branching unit is present at an intersect between the first and second trunk terminal and the branch terminal. The branching unit includes a reconfigurable add/drop multiplexers (ROADM) at least one attenuator. A signal is sent from a second terminal of the first and second trunk terminal to the branding unit. The signal may include a branch traffic component trunk traffic component. The branching unit includes at least one attenuator for attenuating the trunk traffic component so that the trunk traffic component of the signal cannot be detected at the branch terminal.

A method may include transmitting, by an optical device, a first channel. The first channel may have a first set of subcarriers. The first channel may be attenuated during transmission by a filter associated with a wavelength selective switch. The method may further include transmitting, by the optical device, a second channel. The second channel may have a second set of subcarriers. The second channel may be attenuated during transmission by the filter associated with the wavelength selective switch. The first channel and the second channel being included in a super-channel. The first set of subcarriers may be selected based on a first signal quality factor associated with attenuation of the first set of subcarriers by the filter. The second set of subcarriers may be selected based on a second signal quality factor associated with attenuation of the second set of subcarriers by the filter.

Methods and devices for manipulating optical signals. In one example, a LCOS (liquid crystal on silicon) device includes a surface bearing an anti-reflection structure. The anti-reflection structure includes i) a physical surface having a topography with features having lateral dimensions of less than 2000 nm and having an average refraction index which decreases with distance away from the surface; and ii) a configuration of the topography, averaged over lateral dimensions of greater than 2000 nm, varies with lateral position on the surface.

This invention relates to provisioning wavelength-selective switches and reconfigurable optical add-drop multiplexers to minimize the bandwidth narrowing effect from the optical filters. Novel architectures and methods are disclosed that can significantly reduce bandwidth-narrowing on channels in a reconfigurable WDM network where a large number of optical filter elements are cascaded. Instead of blocking unused channels as in the prior art, unused channels are selectively provisioned depending on the state of their adjacent channels. Unused adjacent channels of an active channel are provisioned to follow the same path as the active channels. As each channels is deployed, the channel frequency is selected so as to minimize bandwidth narrowing.

To provide an optical communication technology that brings flexibility to ROADM systems.

An optical communication device according to the present invention drops and adds an optical signal from and to wavelength-division multiplexed optical signals that are transmitted on a main path between network terminal stations, the device including: first means and second means capable of selecting an optical signal of a predetermined wavelength from inputted optical signals and of outputting the selected optical signal; third means for splitting optical signals inputted from a first terminal station on the main path into the first means and the second means; fourth means for splitting optical signals inputted from a branch path in the network into the first means and the second means; and fifth means capable of selectively outputting to a second terminal station on the main path either an optical signal outputted by the first means or an optical signal outputted by the second means.

Disclosed herein is wavelength-division multiplexing (WDM) and demultiplexing with signal entry and exit in a common routing surface to increase channel density. In particular, disclosed is a WDM assembly including a plurality of common ports and a plurality of channel sets having one or more channel ports. The WDM assembly includes a first routing surface with a first WDM passband and a second routing surface offset from the first routing surface. The second routing surface is configured to reflect at least one signal passed through the first routing surface back through the first routing surface at a laterally different location. Optical signal paths of at least a portion of the common ports are parallel to and offset from one another. In certain embodiments, such a configuration may increase channel density and decrease a form factor (e.g., footprint).