A system and method for extending the path length of an electromagnetic wave signal traveling between apertures is disclosed. One such system may comprise N arrays having M.sub.1 through M.sub.N apertures, respectively, wherein N2, M.sub.12, and each of M.sub.2 through M.sub.N1, a substantial number of the M.sub.1 apertures in a first array is configured to send the electromagnetic wave signal to a substantial number of the M.sub.2 apertures in a second array through the M.sub.N apertures in a N-th array, the substantial number of the M.sub.2 apertures in the second array through the M.sub.N apertures in the N-th array receiving the electromagnetic wave signal from the substantial number of the M.sub.1 apertures in the first array is configured to redirect the received electromagnetic wave signal back to the substantial number of the M.sub.1 apertures in the first array, and the substantial number of the M.sub.1 apertures in the first array is further configured to send the electromagnetic wave signal to another one of the M.sub.1 apertures in the first array after receiving the redirected electromagnetic wave signal from a M.sub.N-th aperture in the N-th array.

An optical fiber transmission system and method for using the system are provided. The system may include a span of transmission fiber for transmitting light signals through the optical fiber transmission system. The system may include a dispersion compensating module coupled to the span of transmission fiber. The system may include a switchable module including a set of selectable light signal paths, the set of selectable light signal paths including at least one path through a dispersion compensating element. The system may include a processor coupled to the switchable module for selectively monitoring the set of selectable light signal paths, where the processor is further configured to derive a metric based on the set of selectable light signal paths for controlling the dispersion compensating module.

A frequency chirp correction method for the photonic time-stretch system comprises acquiring the stretching signal, i.e. acquiring the time-domain data after the time-domain stretching. First, the time-domain data of the stretching signal is Fourier transformed to obtain the spectral distribution. The spectral distribution is then convoluted with the first frequency-domain correction factor, and then multiplied with the second frequency-domain correction factor to obtain the modified frequency spectrum. Finally, the modified frequency spectrum is performed by the inverse Fourier transform to obtain the time-domain signal after the frequency chirp correction.

A frequency chirp correction method for the photonic time-stretch system comprises acquiring the stretching signal, i.e. acquiring the time-domain data after the time-domain stretching. First, the time-domain data of the stretching signal is Fourier transformed to obtain the spectral distribution. The spectral distribution is then convoluted with the first frequency-domain correction factor, and then multiplied with the second frequency-domain correction factor to obtain the modified frequency spectrum. Finally, the modified frequency spectrum is performed by the inverse Fourier transform to obtain the time-domain signal after the frequency chirp correction.

Methods and systems relating to administration of authentication information for electronic access control are disclosed. Authentication information is conveyed to an electronic locking device configured to restrict access to an entry point. In various embodiments, a smart device comprises a display screen for presenting a machine-readable optical code comprising encoded authentication information. An image sensor of the electronic locking device can decode the machine-readable optical code to obtain the authentication information. The electronic locking device is configured to permit access to the entry point in response to the image sensor detecting a machine-readable optical code corresponding to an access credential. A server device can provide authentication information to the smart device based on an access criterion. Conveying authentication information to the locking device may include rendering a webpage comprising the machine-readable optical code corresponding to the access credential.

An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 22 splitters to form an optical loop. A second entry port of a first 22 splitter is for coupling with an input fiber and a second exit port of a second 22 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.

The present disclosure provides signal management with unequal eye spacing by: sending, from a local transmitter, first and second signals with different first and second known eye patterns to a remote receiver over a channel; sending temperature data of the local transmitter and operating wavelength data of the first and second signals to the remote receiver over the channel; receiving, from the remote receiver, tuning parameters based on a dispersion of the channel based on a first difference between the first known eye pattern as transmitted and as received and a second difference between the second known eye pattern as transmitted and as received; and adjusting transmission rail values used to encode data for transmission over the channel by the local transmitter based on the tuning parameters to produce a conditioned signal for transmission with an unequally spaced eye pattern.

The present disclosure provides signal management with unequal eye spacing by: sending, from a local transmitter, first and second signals with different first and second known eye patterns to a remote receiver over a channel; sending temperature data of the local transmitter and operating wavelength data of the first and second signals to the remote receiver over the channel; receiving, from the remote receiver, tuning parameters based on a dispersion of the channel based on a first difference between the first known eye pattern as transmitted and as received and a second difference between the second known eye pattern as transmitted and as received; and adjusting transmission rail values used to encode data for transmission over the channel by the local transmitter based on the tuning parameters to produce a conditioned signal for transmission with an unequally spaced eye pattern.

A metasurface optical pulse shaper includes a metasurface with superpixels disposed on an entry side of the metasurface and a wire grid polarizer disposed on an exit surface of the metasurface for controlling a phase, amplitude, or polarization of an optical pulse, wherein the metasurface in combination with dispersers provide for optical shaping of the optical pulse. A process for optically changing a pulse shape includes dispersing a primary optical pulse; separating spatially, by frequency, primary frequency waves; changing, by superpixels, a relative phase of the primary frequency waves and producing phase waves that are separated spatially by frequency and phase; and producing a plurality of shaped frequency waves such that, from an individual phase wave, a shaped frequency wave is produced that separated spatially by frequency and phase, such that a superposition of shaped frequency waves produce a shaped optical pulse that has pulse shape that is different than the primary optical pulse.

There is provided a transmission apparatus including a transmitter configured to modulate a signal to a first signal having a first wavelength and a signal to a second signal having a second wavelength, and transmit the first signal and the second signal to a transmission line so that the second signal is varied in accordance with variation in an amount of cross phase modulation of the first signal passing through each position on the transmission line, and a signal processor configured to include at least one of a logic device and a processor, and configured to add an amount of chromatic dispersion at which a remaining amount of chromatic dispersion of the first wavelength at a certain position on the transmission line is equal to zero to the first wavelength in the transmission of the first signal and the second signal.