基于双光源的可调谐微波光子滤波器

提出了一种基于双光源与双相移光纤光栅(DPS- FBG)的可调谐微波光子滤波器。双光源经过相 位调制后,利用DPS-FBG的反射模式中的两超窄陷波分别对两相位调制光信号的边带进行抑 制,实现相 位调制至强度调制的转换。通过调节两光源的中心波长可以实现单通带与双通带之间的切换 ,实现单通带 的中心频率可调以及3dB带宽可调,实现双通带频率同时可调或者单独可调。建立了理论模 型并进行了数 值分析,最后通过实验进行了验证。实现了滤波器通带的3dB带宽由180MHz增加为319MHz,中心频率从1GHz到7GHz可调。

Tunable microwave photonic filter based on two lasers

A novel tunable microwave photonic filter (MPF) implemented by two tu nable laser sources and dual-phase-shifted fiber Bragg grating (DPS-FBG) is proposed and experime ntally demonstrated in this paper.In the proposed MPF,the two laser sources are modulated by sweeping microwave signals through a phase modulator.One of the sideband of each optical modulated signal is suppressed by each ultra-narrow notch of the DPS-FBG in reflection spectrum,and the phase-modul ation to intensity-modulation conversion is performed.By tuning the wavelengths of the two tunable laser sources to increase spectral interval,the switchability between the single-pas sband filter and the dual-passband filter can be achieved,and the 3-dB bandwidth of the single-pa ss band filter can be tuned. By tuning the wavelengths simultaneously in the same direction by a same ste p,the frequencies of the dual-passband filter can be simultaneously tuned with the frequency interva l maintained.Furthermore, by tuning one wavelength with the other fixed,one passband can be tuned while t he other passband filter is fixed.A theoretical model is established and corresponding simul ation is performed,which is verified by an experiment.In the experiment,the 3dB bandwidth of MPF increases from 180M Hz to 319MHz,and the frequency tuning range from 1GHz to 7GHz is obtained.