AKINETIC SWEPT LASER APPARATUS AND METHOD FOR FAST SWEEPING OF THE SAME

摘要

The present invention discloses a method and apparatus for producing a narrow line laser emission that can be tuned at frequency rates exceeding 100 kHz. The laser apparatus is capable of fast scanning speeds close to multiples of the cavity resonance frequency. The laser cavity can be either a ring or a line resonator. This comprises dispersive means and a nonlinear medium, whose parameter when modulated induces mode-locking, referred from now on as a mode-locking mechanism block, an optical amplifier used as a gain medium and a splitter that ensures that a certain percentage of the laser emission from the gain medium is tapped outside the cavity. The driving method is accomplished with an electronic mechanism that includes a controller drive sweeping generator and a voltage controlled oscillator that injects a tunable radio frequency signal into the nonlinear mode-locking mechanism block. In particular, a semiconductor amplifier can accomplish both functions of amplification and mode-locking, by driving it with RF signals. Two resonant mechanisms are employed to modulate in frequency the mode-locking mechanism block (usually the optical gain in a semiconductor amplifier) and to achieve high frequency tuning rates. The configuration is compatible with working at sweeping rates close to multiples of the cavity resonance frequency as well as with buffering for increased tuning speeds.

主权项

1. Akinetic swept laser apparatus, comprising a laser cavity equipped with a dispersive means, a mode-locking mechanism block, an optical amplifier, and where the laser cavity is characterized by a roundtrip time 1/fR where fR is the resonant frequency of the cavity, a sweeping generator, a controller for the sweeping generator that determines the voltage and the frequency fS of the signal generated be the sweeping generator, a large frequency deviation voltage controlled oscillator that pulsates at a radio frequency fm, whose frequency deviation Δfm is proportional to the voltage applied by the sweeping generator, where the signal pulsating at fS drives the sweeping of the large frequency deviation voltage controlled oscillator,
and wherein the controller is arranged to control the tuning bandwidth of the akinetic laser at a rate fS detuned from multiple values of fR.