Buckling-induced wavy optical fiber attenuator.

An optical attenuator is an optical device that can modulate the power level of an optical signal. Based on the macro-bending loss of optical fibers, we present a wavy fiber attenuator where the attenuation level can be controlled by a mechanical-induced buckling of the fiber. By bonding a fiber to a prestretched substrate and then releasing the prestrain, the fiber flexes into a sinusoidal wavy curve due to the constraints of the substrate. The level of the light attenuation can simply be controlled by stretching the substrate. The maximum attenuation of the proposed wavy optical fiber attenuator is -87.3 dB.

Spectral shaping of fiber Bragg gratings based on non-rigid origami.

We present a spectrum-tunable fiber Bragg grating (FBG) based on a unique compress-twist deformation mode of non-rigid origami. By applying axial displacement on the FBG-bonded Kresling-ori, a non-uniform strain field emerges. The mechanics-induced non-uniform strain can shift the wavelength of an apodized unchirped FBG and/or transform an apodized unchirped FBG to a chirped one. For the spectrum-shaping mode, the bandwidth of the FBG was tuned from 0.32 nm up to 2.9 nm, measured at the -6dB level. For the wavelength-shift mode, a maximum wavelength shift of 0.6 nm can be achieved.