Photonic microwave filter with single bandpass response based on Brillouin processing and SSB-SC
ABSTRACT A photonic structure for microwave filtering with single passband and the capability of continuously tuning the filter response over a broad microwave range is proposed and experimentally demonstrated. The scheme is based on using stimulated Brillouin scattering and single sideband modulation with suppressed carrier (SSB-SC).
Conference Paper: Microwave photonic signal processing[Show abstract] [Hide abstract]
ABSTRACT: Photonic signal processing offers the prospect of realising extremely high multi-GHz sampling frequencies, overcoming inherent electronic limitations. These processors provide new capabilities for realising high time-bandwidth operation and high-resolution performance. In-fibre signal processors are inherently compatible with fibre optic microwave systems, and can provide connectivity with in-built signal conditioning. Recent new methods in wideband signal processors including high-resolution, arbitrary response, low noise, programmable processing, beamforming, and ultra-wide continuous filter tunability, are presented.Microwave Photonics, 2011 International Topical Meeting on & Microwave Photonics Conference, 2011 Asia-Pacific, MWP/APMP; 01/2011
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ABSTRACT: A new structure that realizes a switchable microwave photonic filter, which can be readily switched between a bandpass filter and a notch filter, is presented. It is based on optical processing the sidebands of the RF-modulated signal that is obtained after a dual-drive Mach–Zehnder modulator (DDMZM), using stimulated Brillouin scattering (SBS) effects. Switching of the filter function is simply and conveniently obtained by changing the dc bias to the DDMZM. In addition, the center frequency of the switchable filter can be tuned over a wide frequency range. A detailed analysis and simulation of the DDMZM operation in conjunction with the SBS technique is presented in order to obtain the required optimum bias conditions for the DDMZM for realizing the switching action between the single-bandpass filter and the notch filter and also to select the optimum pump power for the SBS operation. Experimental results demonstrate the ability of this structure to switch between a high-resolution bandpass filter and a high-resolution notch filter, with Q values around 400–500, and the ability to operate over a frequency range of 2–20 GHz.IEEE Photonics Journal 01/2012; 4(5):1443-1455. · 2.36 Impact Factor
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ABSTRACT: We present a novel microwave photonic single-passband filter based on polarization control through simulated Brillouin scattering (SBS). The principle of the filter is based on a vector SBS process, which is different from the previously reported scalar SBS technique. For a radio-frequency (RF) modulated signal launched to the proposed processor, the state of polarization (SOP) of the optical carrier is rotated by 90° through a two-step SBS process. As a result, the RF signals cannot be recovered in the photodetector (PD). To recover the desirable RF signal, the SOP of the RF modulated sideband is rotated by another pump wave. Since the orthogonal polarization condition between the optical carrier and the sideband is destroyed, the desirable RF signal can be recovered. By adjusting the wavelength of the pump wave, the frequency response of the filter is tunable in a frequency range from ~2 to 20 GHz with out-of-band rejection of ~30 dB and -3 dB bandwidth of ~20 MHz. In addition, for any modulation format, it is converted to the single-sideband (SSB) modulation by the proposed filter. Therefore, the system is expected to be immune to the fiber dispersion-induced power fading. Moreover, it is independent of the modulation formats of the incoming signal wave. The filter structure can be inserted anywhere in conventional fiber-optic links without the need for modifying the link configuration and the transmitter.IEEE Photonics Journal 01/2013; 5(4):5501411-5501411. · 2.36 Impact Factor