All-Optical Broadband Variable Optical Attenuator Based on an ${\rm As}_{2}{\rm Se}_{3}$ Microwire

We propose and demonstrate an all-optical broadband variable attenuator based on an ${\rm As}_{2}{\rm Se}_{3}$ microwire. The attenuation of the proposed fiber device as a function of the irradiating power is evaluated for the spectral regions of 1550 and 1850 nm, showing that photoinduced attenuation can be realized over a wide spectral range. We further assess the dynamic response of this variable attenuator upon modulating the amplitude of the irradiating beam.