Optical parametric amplifiers (OPAs) are promising to overcome the wavelength coverage and noise limitations in conventional optical amplifiers based on rare-earth doping and semiconductor gain. However, the high power requirement remains a major obstacle to the widespread use of OPAs. Integrated OPAs can in principle improve the pump efficiency with tight mode confinement; however, challenges associated with propagation loss, limited nonlinearity, and susceptibility to nanoscale fabrication imperfections prevent them from competing with conventional bulk and fiber-based OPAs. Here, we demonstrate a highly efficient integrated OPAs with continuous-wave net gain. The pump efficiency is improved by over one order of magnitude. Phase-sensitive gain of 23.5 dB is demonstrated, significantly exceeding previous integrated OPAs, using only 110 mW pump power and no cavity enhancement. This is achieved with parametric down-conversion in thin-film lithium niobate waveguides using the adapted poling technique to maintain the coherence of nonlinear interactions. Moreover, the high parametric gain exceeds fibre-chip-fibre losses, leading to appreciable net gain up to 10 dB. The 3 dB bandwidth is approximately 120 nm, covering telecommunication S-, C-, and Lbands. Quantum-limited noise performance is confirmed through the measurement of output field fluctuation below the classical limit. We further demonstrate that signalto-noise ratio in noisy optical communications can be increased by leveraging this efficient integrated OPA. Our work marks a significant step towards ideal optical amplifiers with strong amplification, high efficiency, quantum-limited noise, large bandwidth, and continuous-wave operation, unlocking new possibilities for next-generation photonic information processing systems.
Sub 100-fs, 5.2-$μ$m ZGP Parametric Amplifier Driven by a ps Ho:YAG Chirped Pulse Amplifier and its application to high harmonic generation
Vienna University of Technology（维也纳工业大学）；The University of Tokyo（东京大学）；Menlo Systems GmbH（Menlo Systems有限公司）；University of Erlangen-Nuremberg（埃尔朗根-纽伦堡大学）；Center for Physical Sciences & Technology（物理科学和技术中心）
Quantum Battery Enhancement via Degenerate Optical Parametric Amplifier and Common Reservoirs
Northeast Normal University（东北师范大学）；Shenyang Normal University（沈阳师范大学）；RIKEN Center for Quantum Computing (RQC)（理化学研究所量子计算中心）；Ludong University（鲁东大学）；Shangrao Normal University（上饶师范学院）
Photon Blockade Mediated by Two-Photon Absorption in an Optical Parametric Amplifier
School of Optical and Electronic Information, Huazhong University of Science and Technology（华中科技大学光学与电子信息学院）；Synopsys, Inc.（新思科技）；Elmore Family School of Electrical and Computer Engineering, Purdue University（普渡大学埃尔莫电气与计算机工程学院）
