Seminar by Dr Wang 'Ratiometric wavelength measurement systems based on Silicon-on-Insulator integrated devices'

Speaker:
Dr Pengfei Wang
Photonic Research Centre, Dublin Institute of Technology, Dublin, Ireland
Optoelectronics Research Centre, University of Southampton, United Kingdom

Seminar Title:
Ratiometric wavelength measurement systems based on Silicon-on-Insulator integrated devices

Abstract:
Ratiometric wavelength measurement systems based on a Silicon-on-Insulator (SOI) integrated devices are proposed and designed, which consists of directional coupler acting as two edge filters with opposite spectral responses.  The optimal separation distance between two parallel silicon waveguides and the interaction length of the directional coupler are designed to meet the desired spectral response by using local supermodes. The wavelength discrimination ability of the designed ratiometric structure is demonstrated by a beam propagation method numerically and then is verified experimentally. The experimental results have shown a general agreement with the theoretical models. The ratiometric wavelength system demonstrates a resolution of better than 50 pm at a wavelength around 1550 with ease of assembly and calibration. The advantage of this work is that silicon photonics is a new technology that should at least enable electronics and optics to be integrated on the same optoelectronic circuit chip, leading to the production of low-cost devices on silicon wafers by using standard processes from the microelectronics industry. Also the next generation of optical components needs to be low cost and compatible with high-volume manufacturing. Silicon photonics, using highly confined optical modes in silicon waveguide, appears as a unique opportunity to cope with this integration challenge.