Gain-bandwidth relation of electroabsorption-modulated analogue fibre link: effect of photocurrent resistance

The radio-frequency (RF) gain and the bandwidth of the analogue fibre link modulated by an electroabsorption modulator (EAM) are examined at high optical powers. With the inclusion of the photocurrent resistance, which is essential in understanding the EAM link under high optical power, the gain-bandwidth product of the fibre link is shown to be compressed, but less severely than the RF gain owing to the enhancement in bandwidth. It is also pointed out that the link with resonantly enhanced RF gain by negative photocurrent resistance can overcome this gain-bandwidth compression under high optical power owing to more rapid increase in gain than the reduction in bandwidth.