Tunable Microwave Pulse Generation Based on an Actively Mode-Locked Optoelectronic Oscillator

Abstract

A tunable microwave-pulse-generation scheme is proposed and demonstrated by employing an actively mode-locked optoelectronic oscillator (OEO) based on a microwave photonic filter (MPF). The MPF mainly consists of a phase-shifted fiber Bragg grating (PS-FBG) and a phase modulator. The microwave pulse trains with variable repetition rates are achieved by injecting an external signal, of which the frequencies are equal to an integer multiple of the free spectrum range (FSR) of the OEO. The multi-mode oscillation mechanism is discussed in detail theoretically and experimentally. A microwave pulse train with a central frequency of 9.25 GHz and repetition rate of 1.68 MHz is demonstrated by setting the injecting signal frequency to be the same with the FSR of the OEO. A tunable center frequency of the microwave pulses from 5.47 GHz to 18.91 GHz can be easily generated by tuning the laser frequency benefit from adopting the MPF. Furthermore, the microwave pulses with different pulse periods of 297.62 ns, 198.69 ns, and 148.81 ns are also realized by harmonic mode-locking. The proposed tunable microwave-pulse-generation method has potential applications in the pulse Doppler radar and communications.

Simulation of optoelectronic oscillator injection locking, pulling & spiking phenomena

“…There is some literature on baseband spiking phenomena in broadband OEOs triggered by external pulses 15,16 . Mode-locked laser theory and practice is well advanced 17 and OEOs support analogous phenomena [18][19][20][21][22] . Lugiato et al 39 and Usacheva et al 40 report simulation results of the complex dynamics of, respectively, a semiconductor laser and a TDO model under injection by an external carrier.…”

“…Spiking is of interest for the emulation of excitability in neuroscience 15 and its application to high-speed neuromorphic computing 16 . Mode-locked laser theory and practice is well advanced 17 and analogous methods of mode-locking an OEO are being explored for application to pulsed radar systems [18][19][20][21][22] .…”

High resolution frequency shift measurement based on the time domain mode-locked optoelectronic oscillator

“…Recently, the time domain mode-locked OEO (TDML-OEO) is put forward to generate multimode oscillations and at the same time contributes to the circulate oscillation modulation [12][13][14][15][16]. Different structures to lower the sidemode suppressions have also been proposed and discussed [17][18][19][20].…”

Spectral Manipulations of Random Fiber Lasers: Principles, Characteristics, and Applications

“…Particularly, significant advancements in the spectral properties of RFLs have emerged in the aspects of numerical modeling and physical mechanism investigation, lasing wavelength extension, spectrum manipulation, and the applications of spectral‐tailored RFLs, etc. [ 14,26–35 ]…”