Externally-Triggered Spiking and Spiking Cluster Oscillation in Broadband Optoelectronic Oscillator

Abstract

An approach to generating periodic spiking and spiking cluster in a broadband nonlinear opto-electronic oscillator (OEO) is proposed and demonstrated. Through injecting a long-duration square-wave pulse train with a repetition frequency equal to an integral multiple of the free spectral range into the OEO with a high net gain, controllable spiking and spiking cluster oscillation can be achieved when the dual-drive Mach-Zehnder modulator (DDMZM) in the OEO is biased far away from its quadrature point. The proposed scheme is verified by both numerical simulation and experiment. The results indicate that, when the DDMZM in the OEO cavity is biased near its minimum transmission point, positive spiking train with nanosecond-level pulse width is excited by the rising edge of the injected square-wave pulse train. Through further enhancing the injection strength, uniformly-spaced positive spiking fills the high-level voltage duration of each injected square-wave pulse. Hence, spiking cluster oscillation is achieved. Benefiting from its controllability, this approach can be applied in ultra-wideband (UWB) communications, electronic countermeasures, spiking coding and high-speed neuromorphic computing.

Simulation of optoelectronic oscillator injection locking, pulling & spiking phenomena

“…TDOs such as lasers and OEOs support a multitude of modes and consequently, spiking phenomena is to be expected. 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] .…”

“…This paper reports on the phase spike trains, and the width of the spike is inversely proportional to the bandwidth of the RF resonator, as observed in the simulation results. Tian’s 16 primary interest is to realize spiking cluster oscillation. The model Tian et al 16 uses a real state variable and a concatenation of a simple low pass filter and high-pass filter (which as a bandpass filter has a maximum Q of 0.5).…”

“…Tian’s 16 primary interest is to realize spiking cluster oscillation. The model Tian et al 16 uses a real state variable and a concatenation of a simple low pass filter and high-pass filter (which as a bandpass filter has a maximum Q of 0.5). This serves their purpose by offering a flat passband when the two adjustable break points are sufficiently separated.…”

“…The paper reports the first observation in simulation of mode-locking by injection-induced intraloop phase modulation and is redolent of recent experimental observations reported by Diakonov et al 14 of 2π phase pulse trains generated by a broadband OEO under injection. 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] .…”

“…The interest in the literature seems to be emulation of spiking neurons. Risson et al 15 and Tian et al 16 consider amplitude spikes in very broadband systems rather than complex envelope spikes (i.e. a spike modulated carrier) and certainly there appears to be only one report of phase spike trains arising from explicit injection 14 .…”