Abstract: The present invention relates to a method of producing a stacked, sliced food analogue. The invention finds utility in the field of food production, in particular in the field of production of plant-based food analogues, and specifically plant-based cheese analogues.

Abstract: A transmitter generates a first electrical signal comprising a first low-frequency signal, an empty period, and a pump pulse having a first frequency; and a second electrical signal comprising a second low-frequency signal and at least two probe pulses, each probe pulse having a second frequency that differs from the first frequency. The transmitter modulates first and second optical subcarriers having different polarizations using the first and second electrical signals, respectively. The transmitter generates an optical signal from the first and second optical subcarriers, wherein the first and second low-frequency signals overlap in time, wherein the empty period overlaps in time with one of the probe pulses, and wherein the pump pulse overlaps in time with another one of the probe pulses. The optical signal is detected at a receiver over an optical link, and the receiver uses the optical signal to estimate nonlinear phase shift in the optical link.

Abstract: An asymmetric coherent receiver includes an optical front end configured to split a received optical signal into two paths, wherein the split received optical signal experiences a different optical transfer function in one of the two paths; two photodetectors each configured to detect power one of the split received optical signals in each of the two paths to obtain corresponding electrical signals; and circuitry configured to perform electrical domain extraction of information of each of the corresponding electrical signals from the two paths, wherein the different optical transfer function provides additional information utilized in optical field reconstruction via direct detection.

Abstract: A communication system is configured to generate a perturbed signal by perturbing an amplitude of a spectrum of an original signal in one or more spectral regions, and to propagate the perturbed signal through components of the communication system. The communication system is further configured to obtain a measurement of the perturbed signal in a first spectral region of the one or more spectral regions following the propagation of the perturbed signal, and to calculate an estimate of an impairment associated with the communication system based on the measurement.

Abstract: A transmitter generates a first electrical signal comprising a first low-frequency signal, an empty period, and a pump pulse having a first frequency; and a second electrical signal comprising a second low-frequency signal and at least two probe pulses, each probe pulse having a second frequency that differs from the first frequency. The transmitter modulates first and second optical subcarriers having different polarizations using the first and second electrical signals, respectively. The transmitter generates an optical signal from the first and second optical subcarriers, wherein the first and second low-frequency signals overlap in time, wherein the empty period overlaps in time with one of the probe pulses, and wherein the pump pulse overlaps in time with another one of the probe pulses. The optical signal is detected at a receiver over an optical link, and the receiver uses the optical signal to estimate nonlinear phase shift in the optical link.

Abstract: An asymmetric coherent receiver includes an optical front end configured to split a received optical signal into two paths, wherein the split received optical signal experiences a different optical transfer function in one of the two paths; two photodetectors each configured to detect power one of the split received optical signals in each of the two paths to obtain corresponding electrical signals; and circuitry configured to perform electrical domain extraction of information of each of the corresponding electrical signals from the two paths, wherein the different optical transfer function provides additional information utilized in optical field reconstruction via direct detection.

Abstract: A communication system is configured to generate a perturbed signal by perturbing an amplitude of a spectrum of an original signal in one or more spectral regions, and to propagate the perturbed signal through components of the communication system. The communication system is further configured to obtain a measurement of the perturbed signal in a first spectral region of the one or more spectral regions following the propagation of the perturbed signal, and to calculate an estimate of an impairment associated with the communication system based on the measurement.

Abstract: A system configured to perform a method for estimating external noise in a communication channel between a transmitter and a receiver is described. The method comprises obtaining a measurement of effective noise on decoded symbols at the receiver, the decoded symbols comprising noisy versions of symbols conveyed by a communication signal transmitted over the communication channel. The method further comprises storing a representation of a relationship between the effective noise, external noise in the communication channel, and one or more variable parameters. The method further comprises storing applicable values of the variable parameters, wherein each applicable value is associated with current properties of the transmitter or current properties of the receiver or both. The method further comprises calculating an estimate of the external noise in the communication channel using the effective noise, the applicable values of the variable parameters, and the representation of the relationship.

Abstract: A system configured to perform a method for estimating external noise in a communication channel between a transmitter and a receiver is described. The method comprises obtaining a measurement of effective noise on decoded symbols at the receiver, the decoded symbols comprising noisy versions of symbols conveyed by a communication signal transmitted over the communication channel. The method further comprises storing a representation of a relationship between the effective noise, external noise in the communication channel, and one or more variable parameters. The method further comprises storing applicable values of the variable parameters, wherein each applicable value is associated with current properties of the transmitter or current properties of the receiver or both. The method further comprises calculating an estimate of the external noise in the communication channel using the effective noise, the applicable values of the variable parameters, and the representation of the relationship.

Abstract: A transmitter (102,200) applies a dimensional transformation to preliminary digital drive signals representing symbols, thereby generating transformed digital drive signals (704) designed to represent each symbol using a plurality of first dimensions of an optical carrier (242), the first dimensions distributed over two or more timeslots. The preliminary digital drive signals are designed to represent each symbol using a plurality of second dimensions of the carrier, which differ from the first dimensions. Using the transformed signals, the transmitter generates (706) an optical signal (260). A receiver (102,300) receives (802) an optical signal (360) and determines received digital signals (804) corresponding to the first dimensions. The receiver applies an inverse dimensional transformation to the received digital signals to generate preliminary digital drive signal estimates (806) corresponding to the second dimensions, thereby permitting estimation of the symbols (808).

Abstract: A monitorable hollow core (HC) optical fiber comprises one or more hollow core anti-resonant fiber (HC-ARF) segments and one or more monitoring segments alternatingly connected with the HC-ARF segments, and where each monitoring segment comprises one or more non-HC-ARF constituents. A method for monitoring a monitorable HC optical fiber comprises transmitting one or more first optical signals on the monitorable HC optical fiber, detecting one or more second optical signals on the monitorable HC optical fiber, and monitoring one or more optical properties of the monitorable HC optical fiber using the first optical signals and the second optical signals, where the monitoring is enabled as a result of interactions between the first optical signals and the non-HC-ARF constituents of the monitoring segments.

Abstract: A monitorable hollow core (HC) optical fiber comprises one or more hollow core anti-resonant fiber (HC-ARF) segments and one or more monitoring segments alternatingly connected with the HC-ARF segments, and where each monitoring segment comprises one or more non-HC-ARF constituents. A method for monitoring a monitorable HC optical fiber comprises transmitting one or more first optical signals on the monitorable HC optical fiber, detecting one or more second optical signals on the monitorable HC optical fiber, and monitoring one or more optical properties of the monitorable HC optical fiber using the first optical signals and the second optical signals, where the monitoring is enabled as a result of interactions between the first optical signals and the non-HC-ARF constituents of the monitoring segments.

Abstract: An optical transmitter (102,200) is operable to generate an optical signal (260) by modulating a number N of frequency divisional multiplexing (FDM) subcarriers using transformed digital signals which are determined by applying a pseudo FDM (pFDM) transformation to preliminary digital signals representative of multi-bit symbols. Rather than experiencing the effects of the number N of FDM channels, the optical signal experiences the effects of a different number M of pFDM channels, where M?N. In some examples, the number M of pFDM channels is less than the number N of FDM channels, and frequency-dependent degradations may be averaged across different symbol streams. In other examples, the number M of pFDM channels is greater than the number N of FDM channels, and different symbol streams may experience different frequency-dependent degradations. An optical receiver (102,300) is operable to apply an inverse pFDM transformation to recover estimates of the multi-bit symbols.

Abstract: Systems and method include a detector communicatively coupled to a fiber span; and processing circuitry connected to the detector and configured to digitally sample and process an output of the detector, detect phase changes in the output, and identify an electrostrictive response of the fiber span based on the detected phase changes and based on a dependence of the detected phase changes with frequency. A property of the fiber span can be determined on the electrostrictive response. The property of the optical fiber can include one or more of optical fiber material type, optical fiber material property, optical fiber area, optical fiber geometry, optical fiber condition, optical fiber stress and strain, optical fiber temperature. and optical fiber radiation exposure.

Abstract: An optical transmitter (102,200) is operable to generate an optical signal (260) by modulating a number N of frequency divisional multiplexing (FDM) subcarriers using transformed digital signals which are determined by applying a pseudo FDM (pFDM) transformation to preliminary digital signals representative of multi-bit symbols. Rather than experiencing the effects of the number N of FDM channels, the optical signal experiences the effects of a different number M of pFDM channels, where M?N. In some examples, the number M of pFDM channels is less than the number N of FDM channels, and frequency-dependent degradations may be averaged across different symbol streams. In other examples, the number M of pFDM channels is greater than the number N of FDM channels, and different symbol streams may experience different frequency-dependent degradations. An optical receiver (102,300) is operable to apply an inverse pFDM transformation to recover estimates of the multi-bit symbols.

Abstract: A transmitter (102,200) applies a dimensional transformation to preliminary digital drive signals representing symbols, thereby generating transformed digital drive signals (704) designed to represent each symbol using a plurality of first dimensions of an optical carrier (242), the first dimensions distributed over two or more timeslots. The preliminary digital drive signals are designed to represent each symbol using a plurality of second dimensions of the carrier, which differ from the first dimensions. Using the transformed signals, the transmitter generates (706) an optical signal (260). A receiver (102,300) receives (802) an optical signal (360) and determines received digital signals (804) corresponding to the first dimensions. The receiver applies an inverse dimensional transformation to the received digital signals to generate preliminary digital drive signal estimates (806) corresponding to the second dimensions, thereby permitting estimation of the symbols (808).

Abstract: A digital instruction is generated regarding one or more electrical-to-optical conversion impairments induced at the transmitter of an optical communication system. The digital instruction may be used by the transmitter to reduce the impairments. Alternatively, or additionally, the digital instruction may be used by the receiver of the optical communication system to compensate for the impairments.

Abstract: Generation of data streams for two dimensions comprises compensation for a nonideal response of a signal path in an optical communications signal. The data streams are converted to analog electrical signals which drive two dimensions of an electrical-to-optical converter. Output of the electrical-to-optical converter is coupled through an optical link to an optical-to-electrical converter.

Abstract: Systems and methods for estimating a transmit symbol sequence implemented in a coherent receiver include receiving a nominally error-free information bit sequence subsequent to Forward Error Correction (FEC) decoding; determining a nominally error-free estimate of the transmitted bit sequence based on the nominally error-free information bit sequence; and determining a nominally error-free estimate of the transmit symbol sequence by mapping the transmit bit sequence to transmit symbols. The system and methods can further include comparing a transmit optical field based on the transmit symbols to a received optical field for one or more measurements.

Abstract: Systems and method include a detector communicatively coupled to a fiber span; and processing circuitry connected to the detector and configured to digitally sample and process an output of the detector, detect phase changes in the output, and identify an electrostrictive response of the fiber span based on the detected phase changes and based on a dependence of the detected phase changes with frequency. A property of the fiber span can be determined on the electrostrictive response. The property of the optical fiber can include one or more of optical fiber material type, optical fiber material property, optical fiber area, optical fiber geometry, optical fiber condition, optical fiber stress and strain, optical fiber temperature. and optical fiber radiation exposure.