Intensity modulated photoeffects in InP-MIS capacitors

The effect of intensity modulated optical illumination on the characteristics of an InP-MIS capacitor has been examined theoretically in the paper. On the basis of the model developed, it has been found that the capacitance of the MIS capacitor can be controlled by an intensity modulated optical signal. The capacitance of the device under strong inversion depends on the optical power as well as the modulation frequency. This optically controlled capacitor can be used in the tank circuit of an oscillator for converting an intensity modulated optical signal into a corresponding frequency modulated electrical signal. Due to a low value of mean lifetime of the carriers, the device can be used over a wider range of frequency compared to conventional silicon MOS capacitors