[21p-S611-1~8] 3.15 シリコンフォトニクス

▲ [21p-S611-3] High-efficiency silicon optical modulator based on silicon-nitride-loaded SOI waveguide

〇叢 光偉¹、前神 有里子¹、大野 守史¹、岡野 誠¹、山田 浩治¹ (1.産総研)

キーワード：modulator,silicon photonics

High-speed optical modulator is one of the most critical components in silicon photonic transceivers. Great efforts have been spent to enhance the modulation efficiency of silicon modulators because high-efficient modulators can bring benefits such as low power and small size. The depletion-type silicon modulator usually adopts silicon rib waveguide structures and various designs were reported with the efficiency (V_pL) of 1~4 V·cm. It is difficult for the modulators of half etched silicon rib waveguides to further improve the efficiency because (1) the overlap between optical mode field and depletion region is small; (2) optimum doping profile cannot be achieved for both slab and rib simultaneously due to the thickness difference. In addition, the mode field is sensitive to the etching depth of silicon so that the deviation in etching depth greatly influences the efficiency. In this study, we propose a novel silicon modulator without half etching to the silicon-on-insulator (SOI) layer, which remains flat as it is without any structures fabricated.