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Author(s) Hamad S. Alhokail
Affiliation Department of Electrical Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
Title Spice Analysis for the DC Behavior of the Light Amplifying Optical Switch (LAOS)
Source Journal of King Saud University. Engineering Sciences. Volume 15, No 2. (2003/1423)
Abstract Abstract. A heterojunction phototransistor (HPT) is integrated in series with a light-emitting diode to form an optoelectronic device called Light Amplifying Optical Switch. This device has been shown to switch from low current region to high current region at a voltage called breakover voltage. This switching has been attributed to the presence of optical and electrical feedback mechanisms as well as to gain nonlinearity. A circuit model for such device that took into account different factors affecting the switching behavior has been proposed previously. In this paper, a modification to the previously published circuit is made and a spice model is presented for the modified circuit and hence for the LAOS. The spice results presented here are compared to published results and showed a good qualitative agreement. In addition, several factors that affect the switching behavior of such device are analyzed and a good agreement with published results is achieved. The spice model presented here can be very helpful to engineering students in studying optoelectronic circuits and systems that use LAOS.