High efficiency cascaded third-harmonic generation in a quasi-periodically poled KTiOPO 4 crystal

Augustin Vernay (1) , Lucas Bonnet-Gamard (1) , Veronique Boutou (1) , Sivan Trajtenberg-Mills (2) , Ady Arie (2) , Benoit Boulanger (1)

1 NEEL - OPTIMA - Optique et Matériaux
2 TAU - Tel Aviv University

We performed and studied cascaded third-harmonic generation (THG) in a quasi-periodically poled KTP (QPPKTP) crystal allowing simultaneous phase-matching of the two cascading steps ω + ω → 2ω and 2ω + ω → 3ω. The phase-matching was achieved at the fundamental wavelength λ ω = 1587 nm when the QPPKTP crystal was heated to 95°C. The energy conversion efficiency reached 40% in the picosecond regime for a fundamental energy of 20 µJ that corresponds to an intensity of 1.5 GW/cm 2. It is the highest value of THG efficiency ever reported to the best of our knowledge. The modeling in the case of the depleted pump regime accurately described the experiments.

Domaines: Physique [physics]; Optique [physics.optics]

Augustin Vernay, Lucas Bonnet-Gamard, Veronique Boutou, Sivan Trajtenberg-Mills, Ady Arie, et al.. High efficiency cascaded third-harmonic generation in a quasi-periodically poled KTiOPO 4 crystal. OSA Continuum, 2020, 3 (6), pp.1536-1544. ⟨10.1364/OSAC.395084⟩. ⟨hal-02914676⟩