近日，哈佛大学Capasso, Federico团队研究了中红外激光芯片驱动亮孤子。该研究于2025年4月16日发表在《自然》杂志上。

尽管集成光学频率梳技术不断进步，但到目前为止，在3至12μm的中红外波长范围内的短而明亮的脉冲的紧凑源仍然遥不可及。中红外最先进的超快脉冲发射器是基于近红外或可见光脉冲激光源下变频的复杂、笨重和低效的系统。

研究组展示了一个纯直流驱动的半导体激光器芯片，该芯片以GHz的重复率在8.3μm的中心波长产生1-ps孤子。孤子产生方案类似于无源非线性克尔谐振器。它依赖于有源非线性激光谐振腔中的快速双稳性，不同于传统的无源锁模，后者依赖于可饱和吸收体，或半导体激光器中通过增益调制的有源锁模。

所有组件（驱动激光器、有源环形谐振腔、耦合器和泵浦滤波器）的单片集成实现了交钥匙生成亮孤子，这些孤子在没有主动稳定的情况下可以连续运行数小时。这种设备可以在工业激光铸造厂使用标准制造协议轻松生产。该工作统一了有源和无源微谐振器频率梳的物理学，同时建立了中红外非线性集成光子学技术。

附：英文原文

Title: Driven bright solitons on a mid-infrared laser chip

Author: Kazakov, Dmitry, Letsou, Theodore P., Piccardo, Marco, Columbo, Lorenzo L., Brambilla, Massimo, Prati, Franco, Dal Cin, Sandro, Beiser, Maximilian, Opaak, Nikola, Ratra, Pawan, Pushkarsky, Michael, Caffey, David, Day, Timothy, Lugiato, Luigi A., Schwarz, Benedikt, Capasso, Federico

Issue&Volume: 2025-04-16

Abstract: Despite the continuing progress in integrated optical frequency comb technology1, compact sources of short, bright pulses in the mid-infrared wavelength range from 3 to 12μm so far remain beyond reach. The state-of-the-art ultrafast pulse emitters in the mid-infrared are complex, bulky and inefficient systems based on the downconversion of near-infrared or visible pulsed laser sources. Here we show a purely DC-driven semiconductor laser chip that generates 1-ps solitons at the centre wavelength of 8.3μm at GHz repetition rates. The soliton generation scheme is akin to that of passive nonlinear Kerr resonators2. It relies on a fast bistability in active nonlinear laser resonators, unlike traditional passive mode-locking, which relies on saturable absorbers3, or active mode-locking by gain modulation in semiconductor lasers4. Monolithic integration of all components—drive laser, active ring resonator, coupler and pump filter—enables turnkey generation of bright solitons that remain robust for hours of continuous operation without active stabilization. Such devices can be readily produced at industrial laser foundries using standard fabrication protocols. Our work unifies the physics of active and passive microresonator frequency combs while simultaneously establishing a technology for nonlinear integrated photonics in the mid-infrared5.

DOI: 10.1038/s41586-025-08853-y

Source: https://www.nature.com/articles/s41586-025-08853-y