Microfiber/SiC-nanowire coupler for all-optical photodetection

Semiconductor-based photodetectors have received wide attention. Traditional photodetectors are based on electrical test methods, which inevitably disturbed by dark current noise. In order to overcome this problem, this paper proposes an all-optical photodetection scheme based on a microfiber/SiC-nanowire directional coupling structure, which directly utilizes the refractive index change of SiC nanowire caused by photogenerated carriers instead of the change of photocurrent. The device is fabricated by transferring a single SiC nanowire to a microfiber with diameter of about 1 μm by microscopic operating system. When the device is irradiated by a 266 nm deep ultraviolet laser, its light detection sensitivity reaches up to 103 pm/(W/cm2).