Fig. 5. Strain manipulation of the SHG in the WOFN.

a Experimental set-up for control of the SHG in the WOFN. The WOFN is clamped on two translation stages. The linear polarization of the pump light can be tuned by a composite polarizer and half-wave plate. b Polar image of the measured SHG intensity, as a function of the linear polarization of the pump light with a fixed light power. c Reversible strain modulation of the SHG intensity of the WOFN. d Cycling tests of strain modulation of the SHG of the WOFN. Each stretch/relax step corresponds to a strain value of 0.45%. The dashed lines indicate the intensity fluctuations of the SHG