Graphene-Based Integrated Optical Phase Modulator at Visible Wavelengths

Optical phase modulators are critical components in integrated photonic systems operating at visible wavelengths. However, current solutions to integrated optical phase modulators at visible wavelengths face challenges such as high insertion losses, large footprints, low bandwidth, and high-power consumption. In this work, we introduce a graphene-based integrated optical phase modulator designed for operation at 488 nm, implemented on silicon nitride photonic integrated circuits. This design aligns seamlessly with standard silicon photonic processes. The 3-dB bandwidth of the integrated optical phase modulator ranges from 3 GHz to 148 GHz depending on design and fabrication conditions, and a 74 GHz 3-dB bandwidth is considered achievable based on previously published results. Meanwhile, a modulation efficiency (quantified by the product of the $\pi $ -phase shift voltage and length, $\boldsymbol {V_{\mathrm {\pi }}L}$ ) of 0.13 V $\cdot $ cm could be attained. Moreover, the modulator is capable of operating across the entire visible wavelength range. This investigation presents a compact, high-speed solution to integrated optical phase modulators at visible wavelengths, facilitating a broad range of applications in the visible spectrum.