A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

A system for transmitting data over an optical communication path is configured to receive data to be encoded in a bitstream for transmission using an optical communication path and encodes the received data to obtain a bitstream. The system is further configured to determine that the bitstream includes a sequence of consecutive bits, and obtain a power level at which to transmit a portion of the bitstream based on a count of the consecutive bits in the sequence. The system may be configured to selectively activate a light source at a power level according to a modulation scheme to optically transmit the portion of the bitstream at the power level.

A method and structure for compensation techniques in coherent optical receivers. The present invention provides a coherent optical receiver with an improved 8x8 adaptive MIMO (Multiple Input, Multiple Output) equalizer configured within a digital signal processor (DSP) to compensate the effects of transmitter I/Q skew in subcarrier multiplexing (SCM) schemes. The 88 MIMO equalizer can be configured such that each of the 8 outputs is electrically coupled to 3 of 8 inputs, wherein each of the input-output couplings is configured as a filter. The method includes compensating for impairments to the digital conversion of an optical input signal via the 8x8 MIMO equalizer following other signal processing steps, such as chromatic dispersion (CD)/polarization-mode dispersion (PMD) compensation, carrier recovery, timing synchronization, and cycle slip correction.

A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

A method and structure for compensation techniques in coherent optical receivers. The present invention provides a coherent optical receiver with an improved 88 adaptive MIMO (Multiple Input, Multiple Output) equalizer configured within a digital signal processor (DSP) to compensate the effects of transmitter I/Q skew in subcarrier multiplexing (SCM) schemes. The 88 MIMO equalizer can be configured such that each of the 8 outputs is electrically coupled to 3 of 8 inputs, wherein each of the input-output couplings is configured as a filter. The method includes compensating for impairments to the digital conversion of an optical input signal via the 88 MIMO equalizer following other signal processing steps, such as chromatic dispersion (CD)/polarization-mode dispersion (PMD) compensation, carrier recovery, timing synchronization, and cycle slip correction.

A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

In certain examples, methods and semiconductor structures are directed to an apparatus including a photon emitter such as an LED which operates over an emission wavelength range and a photo-voltaic device arranged relative to the photon emitter to provide index-matched optical coupling between the photo-voltaic device and the photon emitter for an emission wavelength range of the photon emitter.

The present disclosure relates to an optical digital-to-analog converter (DAC). The optical DAC includes a first waveguide path configured to receive a first optical signal and a second waveguide path configured to receive a second optical signal. A first phase shifter segment interfaces with the first and second waveguide paths. The first phase shifter segment is configured to selectively generate a first phase shift between the first optical signal and the second optical signal in response to a first digital input. A second phase shifter segment interfaces with the first and second waveguide paths. The second phase shifter segment is configured to selectively generate a second phase shift between the first optical signal and the second optical signal in response to a second digital input. The first digital input and the second digital input correspond to different bits of a digital signal.

A digital-electrical to analog-optical converter for converting a N-bit digital data signal uses a periodically poled non-linear waveguide connected to (i) N optical signals each modulated by a corresponding bit stream of the N-bit digital data signal, (ii) N pump optical signals and (iii) a probe optical signal to generate an output optical signal having an amplitude corresponding to the N-bit digital data signal. The output optical signal is filtered out from other optical signals output from the periodically poled non-linear waveguide by an optical filter.

The invention relates to an optically-based analogue-to-digital converter comprising: a first combiner with a first input for an optical reference signal, and a second input for an input signal that is to be digitised, a second combiner with a first input for a pulsed laser signal, and a second input, which is connected to the output of the first combiner, an evaluation unit, which evaluates the output signal of the second combiner s.