High speed and highly efficient Si optical modulator with MOS junction for 1.55 µm and 1.3 µm wavelengths

We developed a high speed and high efficiency Si optical modulator (Si-MOD) with a metal-oxide-semiconductor (MOS) junction by applying the low optical loss and low resistivity of the poly-Si gate. We designed the optimum Si-MOD structure and demonstrated a very high modulation efficiency of 0.28-0.30 Vcm, which is one of the most efficient in Si-MODs with MOS junctions. We also demonstrated a high speed of 15-25 Gbps for the Si-MOD for both the 1.55 μm and 1.3 μm wavelengths.