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5: Active Mode Locking

  • Page ID
    44655
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    For simplicity, we assume, that the laser operates in the transverse fundamental modes and, therefore, we only have to treat the longitudinal modes of the laser similar to a simple plane parallel Fabry-Perot resonator (Figure: 5.1). We consider one polarization of the field only, however, as we will say later for some mode-locked laser polarization dynamics will become important.

    The task of mode-locking is to get as many of the longitudinal modes lasing in a phase synchronous fashion, such that the superposition of all modes represents a pulse with a spatial extent much shorter than the cavity. The pulse will then propagate at the group velocity corresponding to the center frequency of the pulse.

    截屏2021-04-15 下午7.55.47.png
    Figure 5.1: Fabry-Perot resonator


    This page titled 5: Active Mode Locking is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Franz X. Kaertner (MIT OpenCourseWare) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.