Abstract

On-chip photonic components, particularly for waveguiding and switching applications, are becoming more and more in demand to create high-density photonic integrated circuits in the Terahertz regime. Non-volatile switching can meet the requirement of power saving when the complexity of integrated circuits grows in the near future. Here, we propose and analyze the THz wave switching using the non-volatile phase change material Ge2Sb2Te5 (GST) integrated with a broadband THz dielectric waveguide.
In the proposed switching architecture, a small patch of GST of length 1500 μm is integrated on top of the HRFZ-Si waveguide. It can provide an acceptable insertion loss and high extinction ratio for its broadband operation in the frequency span of 0.5-1.0 THz.
For the proposed device, using a micro-fins-heater, the phase transformation of the GST is carried out through Joule heating. Short electrical pulses of 10 ms and 4 μs are found to be capable of raising the temperature of the GST region above its crystallization and re-amorphozation temperature, respectively. The corresponding energy consumption for crystallization and re-amorphization is found to be 56.6 mJ and 19.84 mJ, respectively. Since GST is non-volatile in nature, no continuous pump power is needed to maintain the particular switching state of the proposed device. The work reported here is a step forward for enabling THz photonic switching, and further THz circuits, in guided wave photonic platform using CMOS-compatible materials