Configurable TE- and TM-Pass Graphene Oxide-Coated Waveguide Polarizer

• Published in: IEEE photonics technology letters 2020-06, Vol.32 (11), p.627-630
• Main Authors: Chong, W. S., Gan, S. X., Lai, C. K., Chong, W. Y., Choi, D., Madden, S., De La Rue, R. M., Ahmad, H.
• Format: Article
• Language: English
• Subjects: Coating; Coatings; Extinction; Graphene; Graphene oxide; Optical fibers; Optical planar waveguides; Optical polarization; Optical waveguides; Planar waveguides; planarized optical waveguide; Polarization; Polarizers; silica; Thickness; Wave propagation
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2020.2988591

A configurable optical waveguide polarizer using graphene oxide (GO) as a polarizing element has been demonstrated. The propagation characteristics of the GO-coated optical waveguide are changed from TM-pass to TE-pass by controlling the GO coating thickness in the sub-micron range during the deposition process. The highest extinction ratio measured for a TM-pass waveguide polarizer is 34.9 dB, using a coating length and thickness of 1.0 mm and 0.34~\mu \text{m} respectively, while the highest extinction ratio measured for a TE-pass polarizer is 46.0 dB, using a coating length and thickness of 1.0 mm and 0.71~\mu \text{m} respectively. The polarization extinction ratio has also been measured across the wavelength range from 1520 nm to 1620 nm - and a variation of less than 3.0 dB was obtained. Control of the coating thickness dependent characteristics of the GO-coated waveguides provides an avenue for tailoring of the polarization selection.