We explore a method in the selection of a specific higher-order mode through judicious shaping of the pump light to create a high modal overlap with the desired mode. To demonstrate this principle, we create a donut-shaped pump profile in the focal plane of a converging lens by use of a beam shaping element. This pump profile is used to longitudinally pump a monolithic microchip laser and a plano-concave resonator cavity where we achieve a TEM01 output with powers of ~12 mW and ~14 mW at slope efficiencies of 17% and 21% respectively. In both cases the modal purity is high with a beam quality factor of ~2. Diffractive pump shaping of this form is advantageous as it allows for high pump intensity even with low pumping powers, thus ensuring sufficient gain is achieved for laser oscillation.
|Level (Hons, MSc, <br> PhD, other)?||MSc|
|Consider for a student <br> award (Yes / No)?||Yes|
|Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?||No|