Intra-pulse difference-frequency generation of mid-infrared (2.7-20 mu m) by random quasi-phase-matching

Zhang, Jinwei; Fritsch, Kilian; Wang, Qing; Krausz, Ferenc; Mak, Ka Fai; Pronin, Oleg (2019): Intra-pulse difference-frequency generation of mid-infrared (2.7-20 mu m) by random quasi-phase-matching. In: Optics Letters, Vol. 44, No. 12: pp. 2986-2989

Abstract

We present a mid-infrared (MIR) source based on intrapulse difference-frequency generation under the random quasi-phase-matching condition. The scheme enables the use of non-birefringent materials whose crystal orientations are not perfectly and periodically poled, widening the choice of media for nonlinear frequency conversion. With a 2 mu m driving source based on a Ho:YAG thin-disk laser, together with a polycrystalline ZnSe element, an octave-spanning MIR continuum (2.7-20 mu m) was generated. At over 20 mW, the average power is comparable to regular phase-matching in birefringent crystals. A 1 mu m laser system based on a Yb:YAG thin-disk laser was also tested as a driving source in this scheme. The new approach provides a simplified way for generating coherent MIR radiation with an ultrabroad bandwidth at reasonable efficiency. (C) 2019 Optical Society of America

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 0146-9592
• Language: English