A system for monitoring coherent optical service channel includes a transmitter configured to generate a multiple polarization signal based on an input signal, a hollow core fiber (HCF) configured to transmit the multiple polarization signal, a receiver configured to receive the multiple polarization signal, and a digital signal processor (DSP) configured to monitor one or more operating parameters of the received multiple polarization signal. The multiple polarization signal may use both the phase and the frequency polarization to multiplex the optical signal.

A communications system has a transmitter circuit for transmitting a communications signal. The transmitter receives a plurality of input data streams and applies an orthogonal function to each of the plurality of input data streams. The transmitter groups the input streams having the orthogonal function applied thereto into a plurality of groups. The orthogonal functions applied to the plurality of input data streams do not repeat within the plurality of groups to limit interference between the input data streams within the group. The transmitter applies a different wavelength to each of the plurality of groups input data streams. The different wavelengths limit interference between the plurality of groups of input data streams. The transmitter applies a positive polarization and a negative polarization to each of the plurality of groups of input data having a different wavelength applied thereto. The positive and the negative polarizations are applied to a pair of groups having a same wavelength applied thereto limit interference between the pair of groups. The transmitter transmits the plurality of input of data streams over a plurality of channels on a communications link as the communications signal. Each of the plurality of channels has a unique combination of orthogonal function, wavelength and polarization associated therewith.

Various embodiments comprise systems, methods, architectures, mechanisms and apparatus for optical, radio frequency (RF), and/or acoustic data transmission by dividing each of one or more sequences of channel coded bits d into N blocks thereof, which are respectively spatially modulated (SM) with respective pilot sequences and mapped to constellations to provide thereby respective symbol streams, which are modulated in accordance with orthogonal signal division multiplexing (OSDM) to provide respective SM-OSDM signals, which are transmitted via optical sources, RF antennae, acoustic transducers, and the like during respective timeslots such that a receiver associated with a plurality of receiving devices may reconstruct the bitstream used to form the one or more sequences of channel coded bits d.

Methods and system for transmitting data includes converting multiple optical beams to distinct respective spatial modes. Data is modulated onto each of the optical beams. The optical beams are combined into a single transmission beam. The transmission beam is launched onto a multimode optical fiber having an elliptical core.

Methods and system for transmitting data includes converting multiple optical beams to distinct respective spatial modes. Data is modulated onto each of the optical beams. The optical beams are combined into a single transmission beam. The transmission beam is launched onto a multimode optical fiber having an elliptical core.

An optical data transmitter includes vertical cavity surface-emitting lasers and an all-optical spatial mode multiplexer. Each vertical cavity surface-emitting laser is configured to output a data modulated optical carrier at a center wavelength of less than one micrometer. The all-optical spatial mode multiplexer has an optical output and optical inputs. Each vertical cavity surface-emitting lasers is optically connected to one or more of the optical inputs of the all-optical spatial mode multiplexer. The all-optical spatial mode multiplexer is configured to cause at least two of the vertical cavity surface-emitting lasers to excite linearly independent combinations of one or more optical spatial propagating modes of an optical fiber in response to the optical output being coupled to a near end of the optical fiber.

A switching instructor outputs a beacon light selection notification signal when a optical transceiver transmits a optical wireless signal of a beacon light and outputs a signal light selection notification signal when the optical transceiver transmits the optical wireless signal of the signal light. A spatial light modulator controller performs switching of a control signal given to each of the plurality of pixels of a spatial light modulator to: cause a phase delay in light received by each of the plurality of pixels of the spatial light modulator when the switching instructor outputs the beacon light selection notification signal and cause a phase delay in light received by each of the plurality of pixels of the spatial light modulator when the switching instructor outputs the signal light selection notification signal.

A method for transmitting optical signals over multiple channels is provided, the method including: coding tributaries of data to be transmitted; firstly rearranging the coded tributaries, thereby scrambling the data among the coded tributaries and outputting rearranged coded tributaries; modulating optical carriers with data from one of the coded tributaries, creating modulated optical signals; transmitting the modulated optical signals; spatially multiplexing the modulated optical signals into spatially multiplexed channels; converting the spatially multiplexed optical signals into individual optical signals; receiving the individual optical signals through the multiple channels; demodulating the individual optical signals into electrical signals; decoding the electrical signals into decoded tributaries; and secondly rearranging the decoded of tributaries to recover the tributaries of data before step, wherein, a number of tributaries of data is equal to or more than two and is less than or equal to a number of the multiple channels.

The invention relates to an optical fiber comprising an optical core and an optical cladding surrounding the optical core, the optical core having a single graded-index profile with 1, and the optical core having a radius R1 and a maximal refractive index n.sub.0, said optical cladding having a refractive index n.sub.Cl. Said optical cladding comprises a region of depressed refractive index n.sub.trench, having an inner radius R.sub.2, with R.sub.2R.sub.1, and an outer radius R3, with R3>R2. According to embodiments of the invention, the -value of said graded index profile and the optical core radius R.sub.1 are chosen such that R.sub.113.5 m and so as to satisfy a criterion C of quality. Thus, the invention provides a few-mode optical fiber, which allow guiding an increased number of LP modes as compared to prior art FMFs, while reaching the lowest Differential Mode Group Delay. The system reach is thus increased over prior art.

The disclosed systems and methods are for monitoring optical performance in a spatial division multiplexing (SDM) system, comprising: i) extracting, by an optical coupler, at least a portion of a plurality optical signals propagating in different communication lanes of the SDM-based optical communication system, wherein each optical signal of the plurality of optical signals is modulated with a distinguishable pilot tone (PT) signal; ii) combining, by the optical coupler, the extracted portion of the plurality of optical signals, and generate a combined optical signal; iii) extracting, by a pilot tone detector (PTD), PT signals from the combined optical signal; iv) determining, by the PTD, optical signal specific information included in the PT signals; and v) computing, by the PTD, optical power of each optical signal based on the optical signal specific information.