A liénard oscillator resonant tunnelling diode-laser diode hybrid integrated circuit: model and experiment

We report on a hybrid optoelectronic integrated circuit based on a resonant tunnelling diode driving an optical communications laser diode. This circuit can act as a voltage controlled oscillator with optical and electrical outputs. We show that the oscillator operation can be described by Liénard's equation, a second order nonlinear differential equation, which is a generalization of the Van der Pol equation. This treatment gives considerable insight into the potential of a monolithic version of the circuit for optical communication functions including clock recovery and chaotic source applications

Wireless interrogation of an optically modulated resonant tunnelling diode oscillator

n this work, a resonant tunnelling diode-photo-detector based microwave oscillator is amplitude modulated using an optical signal. The modulated free running oscillator is coupled to an antenna and phase locked by a wireless carrier that allows remote extraction of the information contained in the modulation. An off-the-shelf demodulator has been used to recover the envelope of the baseband data originally contained in the optical signal. Data were successfully transmitted at a rate of 1 MSym/s with a bit error rate below 10−6

Resonant Tunnelling Optoelectronic Circuits

Nowadays, most communication networks such as local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs) have replaced or are about to replace coaxial cable or twisted copper wire with fiber optical cables. Light-wave communication systems comprise a transmitter based on a visible or near-infrared light source, whose carrier is modulated by the information signal to be transmitted, a transmission media such as an optical fiber, eventually utilizing in-line optical amplification, and a receiver based on a photo-detector that recovers the information signal (Liu, 1996)(Einarsson, 1996). The transmitter consists of a driver circuit along a semiconductor laser or a light emitting diode (LED). The receiver is a signal processing circuit coupled to a photo-detector such as a photodiode, an avalanche photodiode (APD), a phototransistor or a high speed photoconductor that processes the photo-detected signal and recovers the primitive information signa

Optoelectronic Oscillators for Communication Systems

International audienceWe introduce and report recent developments on a novel five port optoelectronic voltage controlled oscillator consisting of a resonant tunneling diode (RTD) optical-waveguide integrated with a laser diode. The RTD-based optoelectronic oscillator (OEO) has both optical and electrical input and output ports, with the fifth port allowing voltage control. The RTD-OEO locks to reference radio-frequency (RF) sources by either optical or electrical injection locking techniques allowing remote synchronization, eliminating the need of impedance matching between traditional RF oscillators. RTD-OEO functions include generation, amplification and distribution of RF carriers, clock recovery, carrier recovery, modulation and demodulation and frequency synthesis. Self-injection locking operation modes, where small portions of the output electrical/optical signals are fed back into the electrical/optical input ports, are also proposed. The self-phase locked loop configuration can give rise to low-noise high-stable oscillations, not limited by the RF source performance and with no need of external optoelectronic conversion

Chaotic dynamics in resonant tunneling optoelectronic voltage controlled oscillators

A new way of generating electrical and optical chaotic carriers is demonstrated using an optoelectronic voltage controlled oscillator consisting of a laser diode (LD) driven by a resonant tunneling diode (RTD) perturbed by radio-frequency signals. The high-dimensional broadband (gigahertz-wide) chaotic current produced by the RTD modulates a LD, providing a simple way to convert electrical chaotic signals into optical subcarriers that can be transmitted by conventional optical channels. Since the chaotic current and the chaotic optical subcarriers are controlled accurately and reproducibly by the RTD, we anticipate this concept can be used as the core of a compact, simple, and low-power consumption optical chaos generator for optical communications

DC characterisation of tunnel diodes under stable non-oscillatory circuit conditions

A common problem in designing with Esaki tunneling diodes in circuits is parasitic oscillations, which occur when these devices are biased in their negative differential resistance (NDR) region. Because of this, the measured current-voltage (I-V) characteristics in the NDR region are usually incorrect, with sudden changes in current with voltage and a plateaulike waveform in this region. Using a full nonlinear analysis of the shunt-resistor-stabilized tunnel diode circuit, we have established the criteria for the range of element values that give stable operation. On this basis, I-V measurement circuits can be designed to be free from both low-frequency bias oscillations and high-frequency oscillations. The design equations lead to a direct I-V measurement setup in which the stabilization resistor in series with a capacitor can be employed. Experimental results validate the approach, and this is confirmed by second-derivative analysis (d<sup>2</sup>I/dV<sup>2</sup>) of the measured I-V characteristics

Modeling of light-sensitive resonant-tunneling-diode devices

We present a method to include the effects of light excitation on two different models of resonant-tunneling-diode-based devices. Our approach takes into account both photoconductive and charge accumulation effects responsible for shifting the static I–V curve when the structure is under light excitation. Computational simulations led to good agreement between the model and experimental results