Demonstration of on-chip multi-mode phase-sensitive amplification

Abstract

Phase-sensitive amplification (PSA) is a nonlinear optical interaction providing attractive functionalities for all-optical classical and quantum signal processing with a wide range of promising applications, such as regeneration of high modulation formats [1] and amplification of entangled single-photon sources [2]. To exploit PSA in a scalable and compact implementation, this technique has been recently explored in various platforms, such as chalcogenide [3], crystalline [4, 5] and amorphous [6] silicon, GaInP [7], and SiGe [8]. However, the performance of PSA in these platforms is limited due to either high losses or material instability. Therefore, a stable CMOS-compatible nonlinear platform with high nonlinearity and low linear and nonlinear losses is desirable for PSA applications. Simultaneous to these developments in optical integration, novel optical operation schemes, such as multiple channel operation, have been developed to increase the information processing capabilities. So far, all the on-chip PSA demonstrations operated on single channel [3-8] and only a few works have simultaneously processed multiple channels in a single device, such as PPLN-waveguides [1] and large scale optical fibers [9]. Here, by taking advantages of a 45 cm-length spiral highly-nonlinear waveguide with ultralow propagation loss (0.08 dB cm−1), moderate nonlinearity (0.22 W−1m−1) and negligible nonlinear losses, we show the manipulation of a four-channel PSA process through the control of the initial phases, achieving a channel-selective as well as synchronized amplification with a net gain of 5 dB and an extinction ratio of 15 dB over a spectral bandwidth of 24 nm.