Making ultrafast cycles of light The ability to generate coherent optical frequency combs has had a huge impact on precision metrology, imaging, and sensing applications. On closer inspection, the broadband “white light” generated through the interaction of femtosecond mode-locked laser pulses is composed of billions or trillions of precisely spaced wavelengths of light. Carlson et al. demonstrate an alternative to the mode-locked laser approach—the electro-optic modulation of a continuous-wave laser light source can also generate optical frequency combs (see the Perspective by Torres-Company). The electro-optic modulation techniques can operate at much higher repetition rates than mode-locked lasers, which means they could potentially yield even more precise measurements. Science, this issue p. 1358; see also p. 1316 Electro-optic modulation of a continuous-wave laser is used to produce ultrafast and ultrastable optical frequency combs. Light sources that are ultrafast and ultrastable enable applications like timing with subfemtosecond precision and control of quantum and classical systems. Mode-locked lasers have often given access to this regime, by using their high pulse energies. We demonstrate an adaptable method for ultrastable control of low-energy femtosecond pulses based on common electro-optic modulation of a continuous-wave laser light source. We show that we can obtain 100-picojoule pulse trains at rates up to 30 gigahertz and demonstrate sub–optical cycle timing precision and useful output spectra spanning the near infrared. Our source enters the few-cycle ultrafast regime without mode locking, and its high speed provides access to nonlinear measurements and rapid transients.

中文翻译：

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具有亚周期控制的超快电光灯

制造超快光循环 产生相干光频率梳的能力对精密计量、成像和传感应用产生了巨大影响。仔细观察，飞秒锁模激光脉冲相互作用产生的宽带“白光”由数十亿或数万亿个精确间隔的光波长组成。卡尔森等人。展示了锁模激光方法的替代方案——连续波激光光源的电光调制也可以产生光频梳（参见 Torres-Company 的观点）。电光调制技术可以以比锁模激光器高得多的重复率运行，这意味着它们有可能产生更精确的测量结果。科学，这个问题 p。1358; 另见第。1316 连续波激光器的电光调制用于产生超快和超稳定的光频梳。超快和超稳定的光源可实现诸如亚飞秒精度计时以及量子和经典系统控制等应用。锁模激光器通过使用它们的高脉冲能量通常可以进入这种状态。我们展示了一种基于连续波激光光源的普通电光调制的低能量飞秒脉冲超稳定控制的适应性方法。我们表明我们可以以高达 30 GHz 的速率获得 100 皮焦耳脉冲序列，并证明了亚光周期计时精度和跨越近红外的有用输出光谱。我们的源进入没有锁模的少周期超快状态，