Stabilized Lasers as Sensors and Frequency Standards

University Of New Mexico, Albuquerque NM

Investigators

Abstract

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?