This paper represents the experimental results of optical modulation characteristics of a resonant tunneling diode-photodiode (RTD-PD) device and novel microwave oscillators employing such RTD-PD. Different from a pure electronic RTD oscillator, the RTD-PDs in this work contain photoconductive layers which make it able to operate in optical conditions. A beam of intensity modulated light with a wavelength of 1310 nm was sent to the free running oscillator via an optical fiber whilst the RTD device was biased in the oscillation condition, and the corresponding electrical data can be extracted from the output port of the oscillator. A square wave signal at data rates up to 10 Gbit/s, and a pseudo random binary sequence (PRBS) signal with a data rate of 100 Mbit/s were preliminarily implemented for modulation.

Polarisation independent strained bulk RSOAs have been fabricated in the S-band for the first time. In system tests at 1.25 Gbit/s, the devices have been shown to operate over >60 nm with large return Path Loss Capabilities (PLC). The devices are capable of providing >25 dB PLC over a 60 nm span and hence the combination of two RSOAs provides PLC of >25 dB over a wavelength interval of >120 nm (1470 nm to 1590 nm). The temperature performance of the C/L band device has also been studied and a PLC of >20 dB has been shown at 60°C.