Spatially modulated broad-area lasers for narrow lateral far-field divergence
Opt. Express, vol. 29, no. 16, pp. 25133-25141, doi:10.1364/OE.430804 (2021).
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A novel laser design is presented that combines a longitudinal-lateral gain-loss modulation with an additional phase tailoring achieved by etching rectangular trenches. At 100 A pulsed operation, simulations predict a far-field profile with 0.3° full width at half maximum (ΘFWHM = 0.3°) where a 0.4°-wide main lobe contains 40% of the emitted optical output power (Θ40% = 0.4°). While far-field measurements of these structured lasers emitting 10 ns long pulses with 35 W peak power confirm a substantial enhancement of radiation within the central 1° angular range, the measured far-field intensity outside of the obtained central peak remains high.
1 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin, Germany
2 Weierstrass Institute for Applied Analysis and Stochastics, Mohrenstr. 39, 10117 Berlin, Germany