This work presents a novel microwave photonic filter using a distributed feedback (DFB) laser. In the proposed filter, the DFB laser is modulated directly by means of the radio-frequency signal to provide a multi-wavelength laser source (MWLS). The proposed filter can thus provide precision for adjusting the central frequency. Moreover, the calculated and experimentally measured responses correlate well with each other. The above results demonstrate that the proposed filter is highly promising for use in practical applications.

This work develops and demonstrates a double sideband with optical carrier suppression (DSBCS) modulation scheme for a hybrid wireless and cable television system based on a phase modulator (PM) and a polarization beam splitter (PBS). A carrier suppression ratio greater than 20 dB is achieved between two sidebands. In addition, the values of carrier-to-noise ratio, composite second-order and composite triple beat in various channels after 25 km of transmission are higher than the threshold value, and the power penalty of microwave signal in back-to-back and 25 km transmission perform well. Additionally, the constellation diagram of upstream signal is successfully recovered. Above results demonstrate that the proposed scheme is highly promising for practical applications.

This work experimentally demonstrates improvement of the fast light property in erbium-doped amplifiers at room temperature. The difference between the signal power and the pump power associated with bending loss is used to control the signal power at the different positions of the erbium-doped fiber (EDF) to improve the fast light property. Periodic bending of the EDF increases the time advance of the probe signal by over 288%. Additionally, this concept also could improve the fast light property using coherent population oscillations in semiconductor optical amplifiers.

This investigation experimentally demonstrates the feasibility of the electrically and continuously tunable optical delay line using a semiconductor laser. The time delays for a 10 Gbps data signal are electrically delayed by adjusting the bias current of laser, and the maximum delay is approximately 41 ps. We also measure the bit error rate against the receiver power by various bias currents and wavelength detuning (Á). Measurements are made to verify the feasibility to use in optical communication systems.

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