An optically tunable wideband optoelectronic oscillator based on a bandpass microwave photonic filter.
An optoelectronic oscillator (OEO) with wideband frequency tunability and stable output based on a bandpass microwave photonic filter (MPF) has been proposed and experimentally demonstrated. Realized by cascading a finite impulse response (FIR) filter and an infinite impulse response (IIR) filter together, the tunable bandpass MPF successfully replaces the narrowband electrical bandpass filter in a conventional single-loop OEO and serves as the oscillating frequency selector. The FIR filter is based on a tunable multi-wavelength laser and dispersion compensation fiber (DCF) while the IIR filter is simply based on an optical loop. Utilizing a long length of DCF as the dispersion medium for the FIR filter also provides a long delay line for the OEO feedback cavity and as a result, optical tuning over a wide frequency range can be achieved without sacrificing the quality of the generated signal. By tuning the wavelength spacing of the multi-wavelength laser, the oscillation frequency can be tuned from 6.88 GHz to 12.79 GHz with an average step-size of 0.128 GHz. The maximum frequency drift of the generated 10 GHz signal is observed to be 1.923 kHz over 1 hour and its phase noise reaches the -112 dBc/Hz limit of our measuring equipment at 10 kHz offset frequency.
Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
Fan
F
Jiang
Jia Haur
JH
Wong
Huy Quoc
HQ
Lam
Junqiang
J
Zhou
Sheel
S
Aditya
Peng Huei
PH
Lim
Kenneth Eng Kian
KE
Lee
Perry Ping
PP
Shum
Xinliang
X
Zhang
D004867:Equipment Design; D019544:Equipment Failure Analysis; D005374:Filtration / Q000295:instrumentation*; D008872:Microwaves; D055096:Optical Devices; D009991:Oscillometry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*