LASER FREQUENCY STABILIZATION BY MEANS OF OPTICAL SELF-HETERODYNE BEAT-FREQUENCY CONTROL

We propose and demonstrate a novel frequency-stabilization scheme that provides Linewidth narrowing and at the same time is compatible with high-speed frequency agility. The method relies on sensing and control of a heterodyne beat signal derived from a fiber interferometer and f unctions in the absence of a fixed reference frequency. Our demonstrat ion utilizes a short-external-cavity diode laser equipped with an intr acavity electrooptic crystal for frequency correction. The stabilizati on method is shown to suppress impressed laser frequency modulation by nearly 2 orders of magnitude. Without further modification of our sch eme we also demonstrate laser frequency tuning control. (C) 1998 Optic al Society of America.