氢化非晶硅波导中的宽带全光调制

Broadband all-optical modulation in hydrogenated-amorphous silicon waveguides.

作者信息

Narayanan Karthik, Elshaari Ali W, Preble Stefan F

机构信息

Microsystems Engineering, Kate Gleason College of Engineering, Rochester Institute of Technology, Rochester, New York 14623, USA.

出版信息

Opt Express. 2010 May 10;18(10):9809-14. doi: 10.1364/OE.18.009809.

DOI:10.1364/OE.18.009809

PMID:20588830

Abstract

We demonstrate broadband all-optical modulation in low loss hydrogenated-amorphous silicon (a-Si:H) waveguides. Significant modulation (approximately 3 dB) occurs with a device of only 15 microm without the need for cavity interference effects in stark contrast to an identical crystalline silicon waveguide. We attribute the enhanced modulation to the significantly larger free-carrier absorption effect of a-Si:H, estimated here to be alpha = 1.6310(-16)N cm(-1). In addition, we measured the modulation time to be only tau(c) approximately 400 ps, which is comparable to the recombination rate measured in sub-micron crystalline silicon waveguides, illustrating the strong dominance of surface recombination in similar sized (460 nm x 250 nm) a-Si:H waveguides. Consequently, a-Si:H could serve as a high performance platform for backend integrated CMOS photonics.

摘要

我们展示了在低损耗氢化非晶硅（a-Si:H）波导中的宽带全光调制。在仅15微米的器件中就出现了显著的调制（约3 dB），无需腔干涉效应，这与相同的晶体硅波导形成鲜明对比。我们将增强的调制归因于a-Si:H显著更大的自由载流子吸收效应，在此估计为α = 1.63×10⁻¹⁶ N cm⁻¹。此外，我们测量到调制时间仅为τc约400 ps，这与在亚微米晶体硅波导中测量的复合速率相当，说明了在类似尺寸（460 nm×250 nm）的a-Si:H波导中表面复合的强烈主导作用。因此，a-Si:H可以作为后端集成CMOS光子学的高性能平台。