Title :
Photonic Polarity-Switchable Ultra-Wideband Pulse Generation Using a Tunable Sagnac Interferometer Comb Filter
Author :
Li, Jianqiang ; Xu, Kun ; Fu, Songnian ; Tang, Ming ; Shum, P. ; Wu, Jian ; Lin, Jintong
Author_Institution :
Key Lab. of Opt. Commun. & Lightwave Technol., Beijing Univ. of Posts & Telecommun., Beijing
Abstract :
A photonic approach to polarity-switchable ultra-wideband (UWB) pulse generation is proposed. The proposed setup principally consists of an electrooptic phase modulator (EOPM) and a tunable optical comb filter constructed with another EOPM inside a Sagnac interferometer. The comb filter working at its linear region performs the phase-to-intensity conversion to generate UWB pulses with monocycle shape. By adjusting the bias voltage of the EOPM inside the Sagnac interferometer, a shift of the comb filter can be achieved, which is the key point for a pulse polarity switch. A pair of monocycle pulses with reversed polarities was experimentally obtained by applying the dc bias of 0 and 1.9 V, respectively. The convenience to electrically control the pulse polarity is favorable for biphase modulation in UWB impulse radio applications.
Keywords :
Sagnac interferometers; electro-optical modulation; microwave photonics; optical filters; optical pulse generation; optical switches; phase modulation; Sagnac interferometer; biphase modulation; electrooptic phase modulator; phase-to-intensity conversion; polarity-switchable ultrawideband pulse generation; pulse polarity switch; tunable optical comb filter; ultrawideband impulse radio applications; Optical filters; Optical interferometry; Optical modulation; Optical pulse generation; Phase modulation; Pulse generation; Pulse modulation; Sagnac interferometers; Switches; Ultra wideband technology; Microwave photonics; Sagnac interferometer; phase modulator; ultra-wideband (UWB);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2008.926944
