Abstract: Systems and methods of polarization-time coding are disclosed. One method includes encoding information in orthogonal polarizations of light and correlated information in multiple time slots, and transmitting the information using the orthogonal polarizations in the time slots. Another method includes receiving a first input pair which specifies a first polarization state and a second input pair containing which specifies a second polarization state; transforming each input pair according to a matrix specifying a conjugate operation to produce four output pairs. The method further includes transmitting at a first time the first output pair using the first polarization state and the third output pair using the second polarization state. The method further includes transmitting at a second time the second output pair using the first polarization state and the fourth output pair using the second polarization state.

Abstract: Efficient apparatus, methods, systems and devices to generate, transmit and detect optical differential polarization-phase-shift keying signals are disclosed for high spectral efficiency optical communication systems. It includes an electrical encoder and an optical encoder for generation of differentially encoded polarization-phase modulated optical signals and optical demodulators and balanced detectors for detection of the optical signals. The optical signals are transmitted through optical fiber links or free space. The electrical encoder maps independent data channels into differentially-encoded data sequences. In the optical encoder, the encoded data sequences from the electrical encoder drive optical modulators to generate differentially-encoded polarization-phase modulated optical signals at a symbol rate equal to the bit rate of each input data channel.

Abstract: This invention provides a method for reducing the effects of process, supply voltage and temperature variations in integrated circuits and its circuit implementation. The disclosed method builds up a detecting-feedback loop with a plurality of target MOS transistors in main circuits, an induction MOS transistor and a current-to-voltage conversion circuit, and performs a body modulation to effectively reduce the parameter fluctuations of the target MOS transistors in a sub-threshold region or a saturated region due to process, supply voltage and temperature variations. A body-modulated circuit achieves the disclosed method with only a few circuit elements, which effectively improves the stability, reliability and product yield of integrated circuits, especially sub-threshold integrated circuits, without significantly increasing the circuit complexity and power consumption.

Abstract: Efficient apparatus, methods, systems and devices to generate, transmit and detect optical differential polarization-phase-shift keying signals are disclosed for high spectral efficiency optical communication systems. It includes an electrical encoder and an optical encoder for generation of differentially encoded polarization-phase modulated optical signals and optical demodulators and balanced detectors for detection of the optical signals. The optical signals are transmitted through optical fiber links or free space. The electrical encoder maps independent data channels into differentially-encoded data sequences. In the optical encoder, the encoded data sequences from the electrical encoder drive optical modulators to generate differentially-encoded polarization-phase modulated optical signals at a symbol rate equal to the bit rate of each input data channel.

Abstract: A communication system may include a first control circuit to detect a break on a first optical link; a first optical source to supply a first optical signal on a second optical link in response to detecting the break on the first optical link, the first optical signal propagating in a first direction on the second optical link; a second control circuit to detect a presence of the first optical signal on the second optical link, and output a control signal in response to detecting the presence of the first optical signal; and a second optical source to supply a second optical signal on the second optical link, the second optical signal propagating in a second direction opposite the first direction, where the Raman pump is disabled in response to the control signal.

Abstract: Efficient apparatus, methods, systems and devices to generate, transmit and detect optical differential polarization-phase-shift keying signals are disclosed for high spectral efficiency optical communication systems. It includes an electrical encoder and an optical encoder for generation of differentially encoded polarization-phase modulated optical signals and optical demodulators and balanced detectors for detection of the optical signals. The optical signals are transmitted through optical fiber links or free space. The electrical encoder maps independent data channels into differentially-encoded data sequences. In the optical encoder, the encoded data sequences from the electrical encoder drive optical modulators to generate differentially-encoded polarization-phase modulated optical signals at a symbol rate equal to the bit rate of each input data channel.

Abstract: A certification method for electronic payment and ID authentication terminal and ATM. When customer would be shopping and pay, the customer sent the electronic-payment certification information to the electronic-payment certificate authority in phone dialing mode, then said authority verifies this information and transmits the certification result to the ID authentication terminal in the merchant-end, the ID authentication terminal will authenticate the ID code supplied by the customer and determine if the payment would be done. ID authentication terminal includes ID code reading module, communication module, indication module and authentication module 5 which compares the ID code reading result with the certification result from the electronic-payment certificate authority.

Abstract: Systems and methods of polarization-time coding are disclosed. One method includes encoding information in orthogonal polarizations of light and correlated information in multiple time slots, and transmitting the information using the orthogonal polarizations in the time slots. Another method includes receiving a first input pair which specifies a first polarization state and a second input pair containing which specifies a second polarization state; transforming each input pair according to a matrix specifying a conjugate operation to produce four output pairs. The method further includes transmitting at a first time the first output pair using the first polarization state and the third output pair using the second polarization state. The method further includes transmitting at a second time the second output pair using the first polarization state and the fourth output pair using the second polarization state.

Abstract: Efficient systems, devices, apparatus and methods to generate, transmit and detect differentially encoded 8-level phase-modulated optical signals for spectrally efficient optical communication systems is invented. It includes an electrical encoder and an optical encoder for generation of differentially encoded 8-level phase-modulated optical signals and optical demodulators and balanced detectors for detection of the optical signals. The optical signals are transmitted through optical fiber links or air. The electrical encoder maps three independent data channels into three differentially-encoded data sequences. In the optical encoder, the encoded data sequences from the electrical encoder drive optical modulators to generate differentially-encoded 8-level phase modulated optical signals at a symbol rate equal to the bit rate of each input data channel.