Transient response of the excited photocurrent inside the optoelectronic integrated device (OEID)

In this paper, the transient response of the excited photocurrent inside an optoelectronic integrated device (OEID) is analyzed. The device is composed of a heterojunction phototransistor (HPT) and a laser diode (LD). The expressions describing the transient response of the output, the rise time, and the output derivative are derived. The effect of the various device parameters on the transient response is outlined. The results show that the transient response of these types of devices is strongly depend on the optical feedback inside the device and it is found that the device works in two different modes, which are: amplification, for small optical feedback coefficient, switching, for high optical feedback coefficient. This type of model can be exploited as an optical amplifier, optical switching device and other applications.