Abstract: In some implementations, a device may apply a modulation to an electrical current to derive a modulated electrical current. The device may supply the modulated electrical current to an optical pump source for an optical amplifier to cause the optical pump source to emit light based on the modulated electrical current. The device may generate a signal based on an optical power of the light emitted by the optical pump source. The device may filter the signal with respect to a feedback signal that is to result from the modulated electrical current to derive a filtered signal. The device may process the filtered signal to identify whether the feedback signal is present in the filtered signal based on a power indicated by the filtered signal. Whether the feedback signal is present indicates a state of the optical pump source.

Abstract: A programmable multicast switch may include a first set of optical ports and a second set of optical ports. The programmable multicast switch may include a plurality of groups of optical devices optically connected in a cascading arrangement. At least one optical device in each of the plurality of groups may be a tunable optical device. Each group may be connected to an optical port of the first set of optical ports. The programmable multicast switch may include a plurality of controllers to tune each corresponding tunable optical devices. The programmable multicast switch may include a processor to control the plurality of controllers. The programmable multicast switch may include a plurality of optical switches connected to each of the groups of optical devices. Each optical switch of the plurality of optical switches may be connected to an optical port of the second set of optical ports.

Abstract: A programmable multicast switch may include a first set of optical ports and a second set of optical ports. The programmable multicast switch may include a plurality of groups of optical devices optically connected in a cascading arrangement. At least one optical device in each of the plurality of groups may be a tunable optical device. Each group may be connected to an optical port of the first set of optical ports. The programmable multicast switch may include a plurality of controllers to tune each corresponding tunable optical devices. The programmable multicast switch may include a processor to control the plurality of controllers. The programmable multicast switch may include a plurality of optical switches connected to each of the groups of optical devices. Each optical switch of the plurality of optical switches may be connected to an optical port of the second set of optical ports.

Abstract: A tunable PLC optical filter having sequentially connected thermally tunable Mach-Zehnder (MZ) interferometers is described. The cascade of MZ interferometers, each having a free spectral ranges matching ITU frequency grid spacing, are tuned so as to have a common passband centered on the frequency of the signal being selected, while having at least one of the stopbands centered on any other ITU frequency. Any other optical channel that may be present at any other ITU frequency is suppressed as a result. Another MZ interferometer in series with the cascade of interferometers including an asymmetric or variable coupler, is tuned to have low transmission at the center frequency of the selected optical channel.

Abstract: A tunable PLC optical filter having sequentially connected thermally tunable Mach-Zehnder (MZ) interferometers is described. The cascade of MZ interferometers, each having a free spectral ranges matching ITU frequency grid spacing, are tuned so as to have a common passband centered on the frequency of the signal being selected, while having at least one of the stopbands centered on any other ITU frequency. Any other optical channel that may be present at any other ITU frequency is suppressed as a result. Another MZ interferometer in series with the cascade of interferometers including an asymmetric or variable coupler, is tuned to have low transmission at the center frequency of the selected optical channel.

Abstract: A tunable PLC optical filter having sequentially connected thermally tunable Mach-Zehnder (MZ) interferometers is described. The cascade of MZ interferometers, each having a free spectral ranges matching ITU frequency grid spacing, are tuned so as to have a common passband centered on the frequency of the signal being selected, while having at least one of the stopbands centered on any other ITU frequency. Any other optical channel that may be present at any other ITU frequency is suppressed as a result. Another MZ interferometer in series with the cascade of interferometers including an asymmetric or variable coupler, is tuned to have low transmission at the center frequency of the selected optical channel.

Abstract: A tunable PLC optical filter having sequentially connected thermally tunable Mach-Zehnder (MZ) interferometers is described. The cascade of MZ interferometers, each having a free spectral ranges matching ITU frequency grid spacing, are tuned so as to have a common passband centered on the frequency of the signal being selected, while having at least one of the stopbands centered on any other ITU frequency. Any other optical channel that may be present at any other ITU frequency is suppressed as a result. Another MZ interferometer in series with the cascade of interferometers including an asymmetric or variable coupler, is tuned to have low transmission at the center frequency of the selected optical channel.

Abstract: A tunable optical filter is configured to take point measurements at a few optical frequencies per frequency channel of a DWDM optical network. The measurement frequencies are shifted by pre-determined amounts relative to the optical frequency channel being characterized. Since the spectral shape of the tunable optical filter is known, the center optical frequency, the modulation bandwidth, and the total optical power of the channel can be obtained from as few as three optical measurements. The center optical frequency and the total optical power can be continuously monitored by providing a tunable filter stage coupled to an interleaver stage, and computing a ratio and a weighted sum the optical signals at the two outputs of the interleaver stage.

Abstract: A tunable optical filter is configured to take point measurements at a few optical frequencies per frequency channel of a DWDM optical network. The measurement frequencies are shifted by pre-determined amounts relative to the optical frequency channel being characterized. Since the spectral shape of the tunable optical filter is known, the center optical frequency, the modulation bandwidth, and the total optical power of the channel can be obtained from as few as three optical measurements. The center optical frequency and the total optical power can be continuously monitored by providing a tunable filter stage coupled to an interleaver stage, and computing a ratio and a weighted sum the optical signals at the two outputs of the interleaver stage.

Abstract: The invention relates to an optical coupling device that provides passive compensation for a shift in center wavelength due to a change in ambient temperature. A conventional solution is to mount one of the elements to be coupled on a pedestal or cantilevered arm, which has a coefficient of thermal expansion (CTE) different from a frame fixed relative to the other of the elements to be coupled. Unfortunately, these devices do not provide consistent results over long periods of time, due to uncontrolled movement of the outer free end of the cantilevered arm or pedestal. The present invention provides an expansion arm fixed on one end to a frame, a holder on the other end of the expansion arm, and a pair of flexible arms connecting the holder to the frame. This arrangement enables the expansion arm to freely expand in a first direction, while greatly restricting movement in any other direction.

Abstract: The invention relates to an optical coupling device that provides passive compensation for a shift in center wavelength due to a change in ambient temperature. A conventional solution is to mount one of the elements to be coupled on a pedestal or cantilevered arm, which has a coefficient of thermal expansion (CTE) different from a frame fixed relative to the other of the elements to be coupled. Unfortunately, these devices do not provide consistent results over long periods of time, due to uncontrolled movement of the outer free end of the cantilevered arm or pedestal. The present invention provides an expansion arm fixed on one end to a frame, a holder on the other end of the expansion arm, and a pair of flexible arms connecting the holder to the frame. This arrangement enables the expansion arm to freely expand in a first direction, while greatly restricting movement in any other direction.