Journal Article

Pushing the limits of CMOS optical parametric amplifiers with USRN:Si7N3 above the two-photon absorption edge

Kimerling, L. C., Ooi, K. J. A., Wang, Q., Agarwal, A. M., Chee, A. K. L., Tan, D. T. H., Wang, T., Ang, L. K., Ng, S. K., Ng, D. K. T.

2017

Overview

CMOS platforms operating at the telecommunications wavelength either reside within the highly dissipative two-photon regime in silicon-based optical devices, or possess small nonlinearities. Bandgap engineering of non-stoichiometric silicon nitride using state-of-the-art fabrication techniques has led to our development of USRN (ultra-silicon-rich nitride) in the form of Si 7 N 3 , that possesses a high Kerr nonlinearity (2.8 × 10 −13  cm 2  W −1 ), an order of magnitude larger than that in stoichiometric silicon nitride. Here we experimentally demonstrate high-gain optical parametric amplification using USRN, which is compositionally tailored such that the 1,550 nm wavelength resides above the two-photon absorption edge, while still possessing large nonlinearities. Optical parametric gain of 42.5 dB, as well as cascaded four-wave mixing with gain down to the third idler is observed and attributed to the high photon efficiency achieved through operating above the two-photon absorption edge, representing one of the largest optical parametric gains to date on a CMOS platform. Typical CMOS materials in the telecommunications band suffer from two-photon absorption or possess weak Kerr nonlinearities. Here, Ooi et al . demonstrate 42.5 dB optical parametric amplification in ultra-silicon-rich nitride waveguides, designed to have strong nonlinearities with negligible losses.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 639/624/399 / 639/766/400/385 / Absorption / CMOS / Design / Fabrication / Humanities and Social Sciences / Light / multidisciplinary / Optics / Photonics / Science / Science (multidisciplinary) / Silicon / Silicon nitride