Flexible signal distribution assisted by tunable optical carrier modulating a desired signal
View Patent ↗A photonic switch device accepts a data modulated RF signal and outputs the data modulated RF signal or a frequency converted version thereof at one or more outputs of the switch device. Tunable laser(s) is/are controlled to cause peak wavelength(s) of the optical signal(s) emitted therefrom. An EOM receives the accepted data modulated RF signal and optical signal(s) produced using the tunable laser(s), and the EOM outputs an optical data signal modulated to include the data modulated RF signal. A WDM receives the optical data signal output by the EOM and the optical data signal received by the WDM demultiplexer is output at one or more outputs thereof based on peak wavelength(s) of the optical data signal. Photodetectors optically coupled to respective outputs of the WDM demultiplexer convert optical signals back to electrical signals. Related methods and system are also described herein.
1. A switch device configured to accept a data modulated RF signal and output the data modulated RF signal, or a frequency converted version of the data modulated RF signal, at only one of N outputs of the switch device at any given time, where N is an integer that is greater than or equal to two, the switch device comprising:
a tunable laser operable to emit an optical signal having a peak wavelength;
a controller configured to control the tunable laser to cause the peak wavelength of the optical signal emitted by the tunable laser to be one of N different wavelengths;
an electro-optical modulator (EOM) including
a first input configured to receive the data modulated RF signal accepted by the switch device,
a second input configured to receive an optical signal produced using the tunable laser, and
an output configured to output an optical data signal that has been modulated to include the data modulated RF signal,
wherein a peak wavelength of the optical data signal that is output by the EOM is one of the N different wavelengths, based on how the controller controls the tunable laser;
a wavelength-division multiplexing (WDM) demultiplexer including an input and N outputs,
wherein the input of the WDM demultiplexer is configured to receive the optical data signal that is output by the EOM, and
wherein at any given time the optical data signal that is received at the input of the WDM demultiplexer will be output at only one of the N outputs of the WDM demultiplexer based on the peak wavelength of the optical data signal, which is based on how the controller controls the tunable laser; and
N photodetectors, each of which is optically coupled to a respective one of the N outputs of the WDM demultiplexer, and each of which provides or is electrically coupled to one of the N outputs of the switch device;
wherein at any given time the data modulated RF signal that is accepted by the switch device, or a frequency converted version of the data modulated RF signal that is accepted by the switch device, will be output by only one of the N photodetectors based on how the controller controls the tunable laser.
2. The switch device of claim 1 , wherein each of the N photodetectors, which is optically coupled to a respective one of the N outputs of the WDM demultiplexer, is configured to convert an optical signal received from a respective one of the N outputs of the WDM demultiplexer to an electrical signal.
3. The switch device of claim 2 , wherein at any given time the electrical signal produced by only one of the N photodetectors comprises the data modulated RF signal that is accepted by the switch device, or a frequency converted version of the data modulated RF signal that is accepted by the switch device.
4. The switch device of claim 1 , wherein by electrically coupling each of the N photodetectors to a respective one of N communication nodes of a communication system, the switch device can be used to selectively provide the data modulated RF signal, or a frequency converted version of the data modulated RF signal that is accepted by the switch device, to only one of the N communication nodes of the communication system at any given time without performing digital switching.
5. The switch device of claim 1 , further comprising:
a local oscillator (LO) configured to output a radio frequency (RF) signal;
a further electro-optical modulator (EOM) including
a first input configured to receive the optical signal having the peak wavelength emitted by the tunable laser,
a second input configured to receive the RF signal output by the LO, and
an output configured to output an RF modulated optical signal;
wherein a peak wavelength of the RF modulated optical signal that is output by the further EOM is one of the N different wavelengths, based on how the controller controls the tunable laser;
wherein the RF modulated optical signal that is output by the further EOM is provided to the first input of the EOM and is used to cause a data modulated RF signal, that is output at any given time by only one of the N photodetectors based on how the controller controls the tunable laser, to be frequency converted compared to the data modulated RF signal that is accepted by the switch device.
6. The switch device of claim 1 , wherein the switch device is configured to be included on a satellite and is used to enable the satellite to perform beam hopping.
7. The switch device of claim 6 , wherein:
the data modulated RF signal accepted from the switch device is produced based on a feeder beam received by the satellite from a gateway; and
the data modulated RF signal or the frequency converted version thereof that is output at any given time by only one of the N photodetectors of the switch device is used to produced a service beam that is transmitted by the satellite to one or more subscriber terminals.
8. A method comprising:
accepting a data modulated RF signal;
controlling a tunable laser to cause a peak wavelength of an optical signal emitted by the tunable laser to be one of N different wavelengths, where N is an integer that is greater than or equal to two;
electro-optically modulating an optical signal produced using the tunable laser with the accepted data modulated RF signal to thereby produce an optical data signal that has been modulated to include the accepted data modulated RF signal and has a peak wavelength that is one of the N different wavelengths, based on how the tunable laser is controlled;
providing the optical data signal, resulting from the electro-optically modulating, to an input of a wavelength-division multiplexing (WDM) demultiplexer that includes N outputs each of which is coupled to a respective one of N photodetectors;
at any given time outputting the optical data signal, that is received at the input of the WDM, at only one of the N outputs of the WDM demultiplexer based on the peak wavelength of the optical data signal, which is based on how the tunable laser is controlled; and
at any given time using only one of the N photodetectors to convert the optical data signal, that is output at only one of the N outputs of the WDM demultiplexer, to an electrical signal that comprises the accepted data modulated RF signal, or a frequency converted version of the accepted data modulated RF signal.
9. The method of claim 8 , wherein each of the N photodetectors is coupled to a respective one of N communication nodes of a communication system, and wherein the method is used to selectively provide the accepted data modulated RF signal, or a frequency converted version of the accepted data modulated RF signal, to only one of the N communication nodes of the communication system at any given time without performing digital switching.
10. The method of claim 8 , further comprising:
using a local oscillator to produce a radio frequency (RF) signal;
electro-optically modulating the optical signal having the peak wavelength emitted by the tunable laser with the RF signal produced using the LO to thereby produce an RF modulated optical signal, wherein a peak wavelength of the RF modulated optical signal at any given time is only one of the N different wavelengths, based on how the tunable laser is controlled;
wherein the RF modulated optical signal, which has the peak wavelength based on how the tunable laser is controlled, comprises the optical signal produced using the tunable laser that is electro-optically modulated with the accepted data modulated RF signal to thereby produce the optical data signal that is provided to the input of the WDM demultiplexer; and
wherein the using of the LO to produce the RF signal and the electro-optically modulating the optical signal having the peak wavelength emitted by the tunable laser with the RF signal produced using the LO to thereby produce the RF modulated optical signal causes the data modulated RF signal, that is output at any given time by only one of the N photodetectors based on how the tunable laser is controlled, to be frequency converted compared to the accepted data modulated RF signal.
11. The method of claim 8 , further comprising using the method on a satellite to perform beam hopping.
12. The method of claim 8 , wherein:
the accepted data modulated RF signal is produced on a satellite based on a feeder beam received by the satellite from a gateway; and
the data modulated RF signal or the frequency converted version thereof that is output at any given time by only one of the N photodetectors is used to produce a service beam that is transmitted by the satellite to one or more subscriber terminals.
13. A switch device configured to accept a data modulated RF signal and output the data modulated RF signal, or a frequency converted version of the data modulated RF signal, at M of N outputs of the switch device, where M is an integer that is greater than or equal to two, and N is an integer that greater than M, the switch device comprising:
M tunable lasers each operable to emit an optical signal having a peak wavelength;
one or more controllers configured to control the tunable lasers to cause the peak wavelength of the optical signal emitted by each of the tunable laser to be one of a plurality of different wavelengths;
M electro-optical modulators (EOMs) each including
a first input configured to receive the optical signal having the peak wavelength emitted by a respective one of the tunable lasers,
a second input configured to receive an RF signal produced using a local oscillator, and
an output configured to output one of M RF modulated optical signals, wherein the peak wavelengths of the M RF modulated optical signals that are output by the M EOMs are based on how the one or more controllers control the M tunable lasers;
an M:1 wavelength division multiplexing (WDM) multiplexer configured to receive the M RF modulated optical signals that are output by the M EOMs and combine M RF modulated optical signals into a wavelength division multiplexed optical signal;
a further EOM including
a first input configured to receive the data modulated RF signal accepted by the switch device,
a second input configured to receive the wavelength division multiplexed optical signal produced by the M:1 WDM multiplexer, and
an output configured to output an optical data signal that has been modulated to include the data modulated RF signal,
wherein M peak wavelengths of the optical data signal that is output by the further EOM are based on how the one or more controllers control the M tunable lasers;
a wavelength-division multiplexing (WDM) demultiplexer including an input and N outputs,
wherein the input of the WDM demultiplexer is configured to receive the optical data signal that is output by the further EOM, and
wherein at any given time the optical data signal that is received at the input of the WDM demultiplexer will be output at M of the N outputs of the WDM demultiplexer based on the M peak wavelengths of the optical data signal, which are based on how the one or more controllers control the M tunable lasers; and
N photodetectors, each of which is optically coupled to a respective one of the N outputs of the WDM demultiplexer, and each of which provides or is electrically coupled to one of the N outputs of the switch device;
wherein at any given time the data modulated RF signal that is accepted by the switch device, or a frequency converted version of the data modulated RF signal that is accepted by the switch device, will be output by M of the N photodetectors based on how the one or more controllers control the M tunable lasers.
14. The switch device of claim 13 , wherein the data modulated RF signal accepted by the switch device comprises a frequency division multiplexed signal that includes data for multiple end users.
15. The switch device of claim 13 , wherein the switch device is configured to be included on a satellite and is used to enable the satellite to perform beam hopping.
16. The switch device of claim 13 , wherein:
the data modulated RF signal accepted from the switch device is produced based on a feeder beam received by a satellite from a gateway; and
the data modulated RF signal or the frequency converted version thereof that is output by one of the N photodetectors of the switch device is used to produced a service beam that is transmitted by the satellite to one or more subscriber terminals.
17. A method comprising:
accepting a data modulated RF signal;
controlling M tunable lasers to each to emit a respective optical signal each having a different respective peak wavelength, where M is an integer that is greater than or equal to two;
electro-optically modulating each of the M optical signals emitted by the M tunable lasers with a respective radio frequency (RF) signal producing using a local oscillator to thereby produce M RF modulated optical signals, wherein the peak wavelengths of the M RF modulated optical signals are based on how the M tunable lasers are controlled;
multiplexing the M RF modulated optical signals to thereby produce a wavelength division multiplexed optical signal that includes M peak wavelengths based on how the one or more controllers control the M tunable lasers;
electro-optically modulating the wavelength division multiplexed optical signal with the accepted data modulated RF signal to thereby produce an optical data signal that has been modulated to include the data modulated RF signal and that has M peak wavelengths that are based on how the one or more controllers control the M tunable lasers;
providing the optical data signal, resulting from the electro-optically modulating the wavelength division multiplexed optical signal with the accepted data modulated RF signal, to an input of a wavelength-division multiplexing (WDM) demultiplexer including an input and N outputs each of which is coupled to a respective one of N photodetectors, where N is an integer that greater than M;
outputting the optical data signal, that is provided to the input of the WDM demultiplexer, at M of the N outputs of the WDM demultiplexer based on the M peak wavelengths of the optical data signal, which are based on how the one or more controllers control the M tunable lasers; and
using M of the N photodetectors to convert the optical data signal, that is output at M of the N outputs of the WDM demultiplexer, to electrical signals that comprise the accepted data modulated RF signal, or a frequency converted version of the accepted data modulated RF signal.
18. The method of claim 17 , wherein the accepted data modulated RF signal is at least one of frequency division multiplexed or time divisional multiplexed so that the accepted data modulated RF signal includes data for multiple end users.
19. The method of claim 17 , further comprising using the method on a satellite to perform beam hopping.
20. The method of claim 17 , wherein:
the accepted data modulated RF signal is produced based on a feeder beam received by a satellite from a gateway; and
the data modulated RF signal or the frequency converted version thereof that is output by M of the N photodetectors is used to produced a service beam that is transmitted by the satellite to one or more subscriber terminals.