Amorphous Electrically Actuating Submicron Fiber Waveguides

Amorphous electrically actuating submicron fiber waveguides are promising building blocks for creating novel opto‐electromechanical devices. In this study, waveguiding and electrically actuating properties of the waveguides composed of racemic poly(lactic acid) and a dye are investigated. The fibers have mean diameters of <0.4 µm, and each fiber demonstrates subwavelength waveguiding with a loss coefficient of 1.5 × 10^?4–8.3 × 10^?4 µm^?1 at 0.63 µm wavelength. Light propagates with a near‐light speed group velocity between wavelengths of 0.59 and 0.63 µm, where the fraction of power inside the core is 0.13–0.28. The fiber mat thicknesses change in response to both the polarity and the magnitude of an applied voltage, similar to the inverse‐piezoelectric effect. The estimated values for both the apparent piezoelectric constant (29 000 × 10^?12 m V^?1) and Young's modulus (1.5 kPa) indicate a high degree of electricity actuation and a soft mat. Extremely small, soft, and electrically actuating waveguides can produce novel opto‐electromechanical devices.