Freely Tunable Dual-Passband Microwave Photonic Filter Based on Phase-to-Intensity Modulation Conversion by Stimulated Brillouin Scattering

Abstract

An approach to achieving a highly selective and stable microwave photonic filter (MPF) with two passbands independently tunable is presented. The dual-passband MPF is realized based on phase-to-intensity modulation conversion by stimulated Brillouin scattering. In the proposed scheme, a freely tunable two-tone pump is generated by passing the optical carrier through two cascaded dual-parallel Mach-Zehnder modulators (DPMZMs), with one acting as a frequency shifter with assistance of an electrical 90°hybrid and the other one working at carrier-suppressed double-sideband modulation mode to generate two-tone pump. The two passband locations of the MPF can be freely set by adjusting the frequencies of the two single-tone signals applied to the two DPMZMs. In the experiment, a dualpassband MPF with flexible passband tunability and shape-invariant tuning is demonstrated in the frequency range of 0-9.644 GHz, where the out-of-band rejection ratio and the 3-dB bandwidth of the passbands are measured to be larger than 25 dB and smaller than 55 MHz, respectively. The proposed MPF scheme also has the ability to tailor the shape and the width of the two passbands, which is a promising solution to achieve a freely programable dual-passband MPF.

Frequency-Sweep-Range-Reconfigurable Complementary Linearly Chirped Microwave Waveform Pair Generation by Using a Fourier Domain Mode Locking Optoelectronic Oscillator Based on Stimulated Brillouin Scattering

“…The flexibility of the proposed scheme can be further enhanced through replacing the MPF in Fig. 1 by a freely-tunable SBS-based dual-passband MPF in [24]. As a result, complementary LCMW pairs can be obtained in either a single frequency band or two independent bands.…”

Microwave Photonic Radars

“…In order to overcome the limitation of periodic filtering characteristics, some single or multi-passband microwave photonic filters were reported [265], [286]- [288]. A single-passband microwave photonic filter based on SBS and a fiber-ring resonator was realized in [286].…”

“…The maximum Q-factor, 3-dB bandwidth and center frequency tuning range of the microwave photonic filter were ∼1.7×10 4 , 825 ± 125 kHz and 2-16 GHz, respectively. In [288], a dual-passband microwave photonic filter with tunable passbands and invariant shape was realized based on phase-modulation to intensity-modulation conversion by the SBS effect, where two cascaded DPMZMs were employed to generate a two-tone pump with programmable frequencies. The two passbands of the proposed filter are freely tuned from 0-9.644 GHz, and the out-of-band rejection ratio and 3-dB bandwidth were larger than 25 dB and smaller than 55 MHz, respectively.…”

An Optical Pulse Shaping Scheme for Simultaneous Photonic Filtering and Digitizing Systems

“…Recently, an simultaneous photonic filtering and digitizing system [1]- [3] has been proposed. The system can achieve the integrated function of filtering and digitizing of input RF signals by combining optical pulse shaping and photonic analog-to-digital convertors (PADC), and therefore avoids multi-stage electro-optic and optic-electric conversion in the direct cascade of microwave photonic filters (MPFs) [4]- [6] and PADCs [7]- [9]. In simultaneous photonic filtering and digitizing systems, the received radio-frequency signals are filtered and modulated by a periodic optical pulse train, and then detected and digitized by low speed photodetector and ADC synchronized with the periodic optical pulse train.…”