This paper reports some of the research work done in the Optoelectronics Research Centre of the City University of Hong Kong. In particular, three areas are discussed: waveguide devices, fibre devices and optical transmission. In the waveguide device area, we report devices such as zero-birefringence polymer waveguides, waveguide Bragg gratings, long period gratings in polymer optical waveguides, X-junction optical waveguide switches, and waveguide optical amplifiers. In the fibre device area, we report devices such as Bragg grating current sensors, long period fibre gratings, Bragg gratings in polymer single mode fibres, segmented cladding polymer optical fibres, and generation of wavelength-tunable short pulses. In optical transmission area, we discuss a communication system based on chaos generated by fibre lasers and soliton trapping within a fibre Bragg grating.