Dissertation Defense - Jason Timothy Meyer "Novel Cavities in Ultrafast Vertical External Cavity Surface Emitting Lasers for High Power Harmonic Generation"

    Wednesday, May 5, 2021 - 1:00pm

    https://zoom.us/j/99147425794?pwd=VVhIaXhpalloRmZpanpCeFZCcnhhQT09 Meeting ID: 991 4742 5794 Passcode: VECSEL674


    Vertical external cavity surface emitting lasers (VECSELs) have seen tremendous growth and development over the past twenty years since its initial demonstration. A key feature that has driven its development is the direct access to the external laser cavity. When combined with various cavity elements, these semiconductor lasers can provide high output powers, tunability, high-quality diffraction-limited beams, and nonlinear frequency conversion to different spectral regions that are difficult, or impossible, to reach with more traditional laser technology. Passively mode locked, or ultrafast, VECSELs can combine many of these same features in ultrashort pulses with high output powers and fast repetition frequencies.

    Most of the published work on ultrafast VECSELs has been conducted at the fundamental wavelength which is typically in the infrared spectral region. This dissertation will primarily explore the development and experimental demonstration of intracavity nonlinear frequency conversion with ultrafast VECSELs to achieve high peak power, ultrashort pulses in the visible and ultraviolet (UV) spectral regions. First, an optimized ultrafast VECSEL in a W-cavity configuration utilizing intracavity second harmonic generation is presented that demonstrates record-setting peak pulse power. Second, a partially overlapped Z-cavity and W-cavity concept is demonstrated for all-intracavity fourth harmonic generation to the UV spectral region. This ultrafast UV laser emitting at 265 nm can deliver 250-300 mW of peak pulse power with 3-4 ps pulses at a repetition frequency of 510 MHz without active stabilization. This opens the door to a new type of ultrafast UV laser source that is significantly more compact and cost effective than what is currently available.

    This dissertation is completed with a new wafer and cavity design for an ultrafast 1550 nm VECSEL for telecommunications applications and, finally, initial results are presented for an ultrafast 1070 nm VECSEL generating higher order Hermite-Gaussian modes that could be useful for free space optical communications.