Self-oscillation and period adding from a resonant tunnelling diode – laser diode circuit

Introduction: Negative resistance elements are important components in oscillator circuits and form the basis of many other nonlinear circuits. Resonant tunnelling diodes (RTDs) have attracted much attention due to their wide-bandwidth negative differential resistance (NDR), up to hundreds of GHz [1]. Because RTDs can be easily integrated in electronic and optoelectronic circuits, the applications span from high frequency signal generation and high speed signal processing to millimetre-wave frequency optoelectronics [2]. In this letter we report self-oscillations, sub-harmonic and harmonic locking and unlocked oscillations in a laser diode hybrid OEIC driver employing a RTD. The circuit operation is similar to the functioning of the resonant tunnelling chaos generator reviewed in [3]. However, the novel aspect here is the optical output. In optical communication systems these operation modes have promising applications including clock recovery, clock division and data encryption.