Uniaxial photomechanical motion in large diameter polydimethylsiloxane optical fibers with fluoropolymer claddings

This study focuses on the photomechanical behavior of step-index optical fibers with a polydimethylsiloxane (PDMS) core and fluoropolymer claddings. The PDMS hosts dopant graphene nanoplatelets, which are heated when illuminated by visible light. Sample fibers were fabricated by drawing the doped resin into thin fluoropolymer tubing before the resin set. The individual motions of the core and cladding were observed to be coupled, which resulted in a relatively small photomechanical effect. Adding a castor oil lubricant between the core and cladding significantly increased the core’s photomechanical strain. The large strain of the lubricated cores exhibited both irreversible and reversible photomechanical motion. Cycling the pump beam resulted in a fully reversible photomechanical piston that can be modeled by a linear response function to the incident pump beam.