Optical down-converter using universal frequency translation technology
First Claim
1. A method of demodulating an optical data signal to retrieve information, comprising:
- receiving the optical data signal with in-phase and quadrature phase components;
optically phase-splitting the optical data signal into in-phase and quadrature components;
converting the phase-split optical signal to electrical charge;
accumulating said electrical charge;
periodically transferring said accumulated charge;
accumulating said transferred charge over multiple charge transfer cycles; and
controllably discharging partially said accumulated transferred charge, resulting in at least one electrical information signal representative of the information that was used to modulate the optical data signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and system for converting an optical signal to electrical information signals, including demodulated baseband information signals and modulated baseband signals at multiple harmonics. In an embodiment, the optical information signal is amplitude modulated with information. The method converts an optical signal to electrical charge, accumulates the electrical charge, and periodically transfers the accumulated electrical charge to a storage device, whereby the periodically transferred electrical charge forms the electrical signals. An exemplary system includes an optical transducer and a universal frequency translator coupled to an output of the optical transducer. The optical transducer receives an optical signal and converts the optical signal to electrical charge. The universal frequency translator periodically transfers energy from the electrical charge and forms the electrical signals from the transferred energy. In an embodiment, the present invention converts an I and Q optical signal to electrical signals. In an embodiment, the present invention converts an optical signal to an RF electrical signal using relatively few components, while preserving information content.
-
Citations
33 Claims
-
1. A method of demodulating an optical data signal to retrieve information, comprising:
-
receiving the optical data signal with in-phase and quadrature phase components; optically phase-splitting the optical data signal into in-phase and quadrature components; converting the phase-split optical signal to electrical charge; accumulating said electrical charge; periodically transferring said accumulated charge; accumulating said transferred charge over multiple charge transfer cycles; and controllably discharging partially said accumulated transferred charge, resulting in at least one electrical information signal representative of the information that was used to modulate the optical data signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A method of demodulating an optical data signal to retrieve information, comprising:
-
receiving the optical data signal with in-phase and quadrature phase components; optically phase-splitting the optical data signal into in-phase and quadrature phase components; converting the phase-split optical signal to electrical charge; accumulating said electrical charge; periodically sampling and storing said accumulated charge over multiple charge transfer cycles, according to a control signal, resulting in at least one electrical information signal; and partially transferring said sampled charge to a load, wherein a voltage across said load forms a demodulated signal that is representative of the information that was used to modulate said optical data signal. - View Dependent Claims (16, 17, 18)
-
-
19. A system for demodulating an optical data signal, comprising:
-
a π
/2 optical phase splitter;at least two optical transducers; a controlled switch pair coupled to an output of said optical transducers, wherein said controlled switch pair samples accumulated charge from an output of said optical transducers according to a control signal; a charge storage device pair coupled to said controlled switch pair, wherein said storage device pair stores sampled charge over multiple charge transfer cycles; and a load coupled to said storage device pair. - View Dependent Claims (20, 21)
-
-
22. A system for demodulating an optical data signal, comprising:
-
a π
/2 optical phase-splitter;at least two optical transducers, each having an optical-to-charge converter; a first charge storage device coupled to an output of said optical-to-charge converter, wherein said first charge storage device accumulates charge; a controlled switch pair comprising a first controlled switch and a second controlled switch coupled to an output of each of said optical transducers, wherein each of said first and second controlled switch samples said accumulated charge according to a control signal; and a second and a third charge storage device coupled to an output of each of said controlled switches, wherein said second and third charge storage devices are configured to store sampled charge over multiple charge transfer cycles from said controlled switch pair, whereby said sampled charge represents a demodulated information demodulated from the optical data signal received at said optical transducer. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29)
-
-
30. A system for demodulating an optical data signal to retrieve an information signal, comprising:
-
an optical phase splitter; an optical transducer, including an optical-to-charge converter; a first charge storage device coupled to an output of said optical-to-charge converter, wherein said first charge storage device accumulates charge; a field effect transistor (FET) coupled to an output of said optical transducer, wherein said FET samples said accumulated charge according to a control signal; and a second charge storage device coupled to an output of said FET, wherein said second charge storage device stores samples of said accumulated charge from said FET over multiple charge transfer cycles, whereby said samples of said accumulated charge represent a demodulated information signal. - View Dependent Claims (31, 32, 33)
-
Specification