Compact plasmon modulator with a high extinction ratio

Abstract

To keep pace with the demands in optical communications, electro-optic modulators should feature a high extinction ratio, offer a small footprint, and allow for practical detection. Herein, we demonstrate a compact plasmon modulator with a high extinction ratio where a compact modulation region composed of indium tin oxide (ITO) is embedded to the arms of the Mach–Zehnder (M–Z) interferometer. The modulator has a footprint of 20 µ m × 12 µ m with a modulation region of 4 µ m × 0.5 µ m . The numerical results show that the extinction ratio is 15.2 dB when the electron concentration of ITO is changed 4 × 10 20 c m − 3 . This type of modulator paves the way for future compact optoelectronic integration and has potential application in the fields of optical communication, photodetection, and sensing.