Resonances inside metallic nanoslots and along metal–substrate interfaces have been investigated theoretically, which shows the fact that the transmission characteristic of a double periodic metallic nanoslot array could be manipulated by adjusting the structural parameters. A transmission structure over a wide band of infrared and terahertz waves has been proposed, with 30 dB isolation between peaks inside the infrared band and high flexibility in tuning.
An all-optical regenerator for Quadrature Phase-Shift Keying (QPSK) and Differential Quadrature Phase-Shift Keying
(DQPSK) signals based on Phase-Sensitive Amplifiers (PSAs) is studied through numerical simulations. It is found that
the regenerator can provide significant suppression of both amplitude and phase noise, and that the BER performance of
the regenerated signals can be greatly improved.