Spontaneous oscillations in the InP-InGaAsP lasing optoelectronic switch (LOES)

We present the first comprehensive experimental and theoretical analyses of spontaneous electrical and optical oscillations that occur when the InP-InGaAsP lasing optoelectronic switch (LOES) is biased in or near the negative differential resistance region of the device characteristic. For a device with a switching voltage and current of ~7 V and 0.5 mA, respectively, electrical oscillations are observed which result in current spikes of up to 613 mA, with a FWHM of 0.6 μs. The repetition rate varies from 900 Hz to 0.22 MHz, increasing with bias current. Pulses of laser light correlated to the current pulses are emitted from the LOES for some circuit configurations. A lumped circuit element model is presented which agrees well with the experimental results, and illustrates the effects of the bias circuit parameters on the device oscillations