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Reconfigurable and tunable multi-tap bandpass microwave photonic filter based on a hybrid-gain-assisted multi-wavelength fiber ring laser

Peng Mengmeng, Wang Fei, Shi Lun, Huang Jingxin, Kang Wen

Optica Applicata

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2019

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Vol. 49, nr 3

499--507

EN

A reconfigurable and tunable multi-tap bandpass microwave photonic filter based on a hybrid-gain-assisted multi-wavelength fiber ring laser (HMFRL) is proposed and experimentally demonstrated. The HMFRL containing a hybrid gain medium and a high birefringence fiber loop mirror serves as the multiple taps generator for the microwave photonic filter. In order to realize a bandpass filter, the multiple taps are phase modulated, then the modulated signal is launched into a coil of dispersion compensating fiber to introduce different time delays for each tap. As a result, a bandpass response is obtained at the output of a high speeding photodetector. By adjusting the bias of the semiconductor optical amplifier from 344 to 450 mA, the number of multiple taps can be increased without optical signal-to-noise ratio degradation. Thus, a multi-tap bandpass microwave photonic filter with bandwidth reconfiguring from 449 to 274 MHz is achieved. In addition, by changing the length of polarization maintaining fiber in the high birefringence fiber loop mirror, the wavelength spacing of the multiple taps can be adjusted, making the bandpass microwave photonic filter’s free spectral range tunable.

2

Polarization dependence of stimulated Brillouin scattering-based switchable microwave photonic filter

Gu Jun, Wang Fei, Lu Youxi, Peng Mengmeng, Shi Lun, Kang Wen, Huang Jingxin

Optica Applicata

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2019

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Vol. 49, nr 1

5--11

EN

We propose and experimentally demonstrate a switchable microwave photonic filter based on polarization dependence of stimulated Brillouin scattering (SBS). The continuous optical wave from a tunable laser source is split into two branches. One branch serves as the SBS pump source and another branch serves as the signal source which are interactional to generate the SBS effect in the dispersion-shifted fiber. Only by adjusting the polarization direction of pump light and signal light, a frequency response switched between bandpass and notch filtering shape can be obtained.

3

Photonic generation of broadly tunable radio-frequency signal using a reflective semiconductor optical amplifier

Lu Youxi, Wang Fei, Gu Jun, Shi Lun, Peng Mengmeng, Huang Jingxin, Kang Wen

Optica Applicata

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2019

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Vol. 49, nr 1

27--36

EN

A novel scheme for photonic generation of broadly tunable radio frequency signal using a reflective semiconductor optical amplifier (RSOA) is demonstrated. A continuous wave emitted from the laser diode is modulated by a Mach–Zehnder modulator, then the modulated optical carrier is injected into the RSOA. Due to the four-wave mixing effect in the RSOA, the limited frequency components of the modulated signal are expanded, which directly lead to the generation of a wide frequency comb. Two optical tunable bandpass filters are parallelly connected to select the desired sidebands, which are launched into a photodetector or photomixer to generate radio frequency signal by beating. Using the proposed method, the bandwidth of generated radio frequency signal can range from 20 to 300 GHz.