Side polished fiber with coated graphene sheet and its control characteristic of violet light

Side-polished fiber (SPF) with a graphene sheet on a polished area can enhance the interaction between graphene and a strong evanescent field of optical fiber. Graphene sheet is utilized due to its saturable absorption property. To investigate the response characteristics of the optical transmitted power (λ = 1550 nm) in the SPF, violet light (λ = 450 nm) as pump source is employed to illuminate the graphene sheet. Experimental results reveal that different pump power can change the optical transmitted power of the SPF. When the pump light changes from 0 mW to 11 mW, the optical transmitted power of the SPF varies ~3.4 dB. In this increasing process of the pump power, the linear correlation between relative transmitted power and violet power is ~97.1% with the sensitivity of ~0.29 dB/mW; while the linear correlation is ~96.5% with sensitivity of ~0.25 dB/mW in the decreasing process of the pump power. These results indicate that violet light (order of mW) can manipulate the optical transmitted power of the SPF coated with graphene sheet, which signifies the device can potentially be applied as all optically controllable devices.