title: Experimental study on the performance of a variable optical attenuator using polymer dispersed liquid crystal.
abstract: We applied polymer dispersed liquid crystal (PDLC) as the cladding material in a polymer-based variable optical attenuator. Three polymer inverted channel waveguides were fabricated, two with PDLC upper cladding (aligned PDLC and nonaligned PDLC) and one with aligned liquid crystal upper cladding. Upon operation, the waveguides with aligned upper claddings show relatively lower threshold and cutoff voltages compared to those with nonaligned PDLC cladding. But the waveguide with nonaligned PDLC upper cladding shows lower polarization dependence and a higher attenuation range of 39 and 41.37 dB for TM and TE modes, respectively, over a tuning field strength of 0.9 V/μm.
authors.affiliation: Electronic Engineering Department, City University of Hong Kong, Kowloon Tong, Hong Kong, China.
authors.forename: Ghada
authors.initials: G
authors.lastname: Nabil
authors.forename: Wing Fat
authors.initials: WF
authors.lastname: Ho
authors.forename: Hau Ping
authors.initials: HP
authors.lastname: Chan