The present disclosure relates to systems and method for deploying a fiber optic network. Distribution devices are used to index fibers within the system to ensure that live fibers are provided at output locations throughout the system. In an example, fibers can be indexed in multiple directions within the system. In an example, fibers can be stored and deployed form storage spools.

A code acquisition module for a direct sequence spread spectrum (DSSS) receiver includes: a Sparse Discrete Fourier transform (SDFT) module configured to perform an SDFT on a finite number of non-uniformly distributed frequencies comprising a preamble of a received DSSS frame to calculate Fourier coefficients for the finite number of non-uniformly distributed frequencies; a multiplier configured to multiply the Fourier coefficients for the finite number of non-uniformly distributed frequencies of the received DSSS frame by complex conjugate Fourier coefficients for the finite number of non-uniformly distributed frequencies to generate a cross-correlation of the received DSSS frame and the complex conjugate Fourier coefficients; and a filter module configured to input the cross-correlation and output a delay estimation for the received DSSS frame.

Disclosed herein are various embodiments for high performance wireless data transfers. In an example embodiment, laser chips are used to support the data transfers using laser signals that encode the data to be transferred. The laser chip can be configured to (1) receive a digital signal and (2) responsive to the received digital signal, generate and emit a variable laser signal, wherein the laser chip comprises a laser-emitting epitaxial structure, wherein the laser-emitting epitaxial structure comprises a plurality of laser-emitting regions within a single mesa structure that generate the variable laser signal. Also disclosed are a number of embodiments for a photonics receiver that can receive and digitize the laser signals produced by the laser chips. Such technology can be used to wireless transfer large data sets such as lidar point clouds at high data rates.

An apparatus includes a reconfigurable optical add/drop multiplexer (ROADM) having an input port to receive a first optical signal from a second device. The ROADM also includes a first wavelength selective switch (WSS), in optical communication with the input port, to convert the first optical signal into a second optical signal, a loopback, in optical communication with the first WSS, to transmit the second optical signal, and a second WSS, in optical communication with the loopback, to convert the second optical signal to a third optical signal and direct the third optical signal back to the second device via the input port.

In order to provide a submarine optical transmission system that utilizes multiple wavelength bands, the submarine branching apparatus is provided with: a first demultiplexing part for demultiplexing a wavelength-multiplex optical signal input from a first terminal station into a first wavelength-multiplex optical signal and a second wavelength-multiplex optical signal; an optical add-drop part for outputting at least a third wavelength-multiplex optical signal included in the first wavelength-multiplex optical signal to a second terminal station, and for outputting a fifth wavelength-multiplex optical signal by multiplexing at least a fourth wavelength-multiplex optical signal included in the first wavelength-multiplex optical signal with a wavelength-multiplex optical signal input from the second terminal station; and a first multiplex part for multiplex the second wavelength-multiplex optical signal with the fifth wavelength-multiplex optical signal input from the optical add-drop part and outputting the resulting signal to a third terminal station.

An object is to perform wavelength filtering of an optical signal while preventing filter narrowing in an optical transmission apparatus. A branching unit branches a wavelength-multiplexed optical signal including an optical signal of a first wavelength into two optical signals. A wavelength selection unit blocks an optical signal of a first wavelength band including the first wavelength in the optical signal. A filter unit allows passage of an optical signal of a second wavelength band including the first wavelength in the optical signal. A multiplexing unit multiplexes and the optical signal and an optical signal of a second wavelength. The second wavelength band is wider than the first wavelength band.

This application provides example signal processing apparatus and example signal processing method. One example signal processing apparatus includes a sampling unit, a beam combiner, and an optical resonator. The sampling unit is connected to the beam combiner, and the beam combiner is connected to the optical resonator. The sampling unit is configured to sample an analog signal by using an optical pulse signal to output a sampled optical pulse signal. The beam combiner is configured to combine the sampled optical pulse signal and a multi-wavelength optical signal into a first optical signal. The optical resonator is configured to perform resonance based on the first optical signal to output a second optical signal in the first optical signal, where a wavelength of the second optical signal is equal to a resonant wavelength of the optical resonator.

An optical circuit is used with continuous wave signals having different wavelengths at a channel spacing from one another. A portion of the optical circuit is implemented in a photonic integrated circuit. Modulators in a modulation stage modulate the continuous wave signals to produce modulated signals. A multiplexing stage, which can have multiplexing filters, power combiners, or power couplers, multiplexes the continuous wave or modulated signals to produce multiplexed signals. The multiplexing stage may be placed either before or after the modulation stage. One or more polarization rotator and combiner (PRC) devices in a final stage combines the multiplexed signals into an output signal. The output signal has a first set of the different wavelengths at a first polarization and has a second separate set of the different wavelengths at a second polarization orthogonal to the first polarization.

A system can include a splitter configured to receive a first optical signal carrying first data and generate a first optical signal copy and second optical signal copy. Also included is at least one optical processing path includes at least one optical encoder configured to transform the first optical signal copy into a second optical signal carrying the first data and an additional optical feature not present in the first optical signal, at least one optical modulator configured to optically modulate the second optical signal according to a compare data to generate an optical match signal that indicates matches between the compare data and the first data, and at least one photodetector configured to generate an electrical match signal in response to the optical match signal. Corresponding methods are also disclosed.

Consistent with the present disclosure, an encoder circuit is provided at a transmit side of an optical fiber link that maps an input sequence of bits of fixed length k a sequence of symbols of a codeword of length n, such that the symbols of the codeword define a predetermined transmission probability distribution. Preferably, each symbol of the codeword is generated during a corresponding clock cycle, such that after n clock cycles, a complete codeword corresponding to the input bit sequence is output. On a receive end of the link, a decoder is provided that outputs the k-bit sequence every n clock cycles. Accordingly, buffers need not be provided at the output of the encoder and the input of the decoder, such that processing of the input sequence, codewords, and output sequence may be achieved efficiently without large buffers and complicated circuitry. Moreover, the input sequence, with any binary alphabet may be matched to a desired output distribution with any arbitrary alphabet. Accordingly, probabilistic constellation shaping may be achieved over constellations of arbitrary size. In addition, relatively long codewords, may be encoded and decoded with the apparatus and method disclosed herein. Accordingly, for a fixed SNR a higher SE (more bits per symbol) can be achieved. Alternatively, for a fixed SE, a lower SNR may be sufficient. Moreover, the resulting SE may be finely tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links.