Time domain RF characterisation of a thin-film metamorphic HEMT under modulated backside illumination

It is shown in this paper how the opto-electrical interaction of a microwave device can be characterized by combining a large-signal network analyzer set-up with a modulated laser module. The concept is demonstrated by measuring a "thin film" M(etamorphic) HEMT under modulated optical (1550 nm laser light) illumination. The advantage of this approach is that the time-domain characteristics of the electrical currents, generated by the modulated laser light, can be visualised and analysed.