Stabilized Lasers as Sensors and Frequency Standards

锁模激光器可以在频率上产生规则间隔模式的梳状结构。我们建议研究稳定锁模环和线性固体激光器提供的频率梳的新方法，以及将梳锁定到原子标准。稳定性是通过将频率和重复率锁定到参考腔体来实现的。我们最近证明了飞秒激光稳定参考腔提供了一个异常快速的反馈控制，以确保在短时间尺度上稳定运行。通过将参考腔锁定在λ (L)结构提供的原子共振上，可以实现精度。工作的第一部分将是我们之前涉及钛蓝宝石锁模激光器的工作的扩展，改进目前的性能，并开发长期稳定和精度的方法和工具。同时，我们将开始开发基于光学参数振荡器的紧凑系统，该系统具有波长和重复率正交控制的优点，并且可以访问广泛的可见光和红外波长。我们将评估这些稳定锁模激光器的应用。特别是，稳定的环形光学参量振荡器将使相移测量具有比非稳定环形激光器获得的10-9值更好的灵敏度。一个具体的应用是作为激光陀螺仪，可用于测地线应用。在项目结束时，同时稳定了至少两个独立的锁模激光器，我们将能够通过注入锁定来研究这些激光器的同步。这将回答超快通信的一个问题：一旦两个独立的源的模式重合到几赫兹，需要多少（或多少）光功率来锁相？

Mode-locked lasers can produce a comb of regularly spaced modes in frequency. We propose to investigate new approaches to stabilize frequency combs provided by mode-locked ring and linear solid state lasers, as well as locking the comb to an atomic standard. The stability is achieved by locking the frequency and repetition rates to a reference cavity. We have recently demonstrated that femtosecond laser stabilization to reference cavities provides an exceptionally fast feedback control to ensure stable operation on short time scales. Accuracy will be achieved by locking the reference cavity to atomic resonances provided by lambda (L) structures. A first part of the work will be an extension of our previous work involving Ti:sapphire mode-locked lasers, improving the present performances, and developing the methods and tools for long term stabilization and accuracy.In parallel, we will start the development of a compact system based on optical parametric oscillators, which has the advantages of orthogonal controls of wavelength and repetition rate, as well as offering access to a broad range of visible and infrared wavelengths.We will evaluate applications for these stabilized mode-locked lasers. In particular, the stabilized ring optical parametric oscillator will enable the measurement of phase shifts with a much better sensitivity than the value of 10-9 that we obtained with unstabilized ring lasers. A specific application is as a laser gyroscope that could be used for geodesic applications. Having at the end of the program simultaneously stabilized at least two independent mode-locked lasers, we will be able to study the synchronization of these lasers through injection lock-in. This will answer a question for ultrafast telecommunication: how much (or how little) optical power is required to phase lock two independent sources, once their modes coincide to a few Hz?