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arXiv · 2104.10855

A compact and stable incidence-plane-rotating second harmonics detector

S. H. Kim·S. Jung·B. Seok·Y. S. Kim·H. Park·T. Otsu·Y. Kobayashi·C. Kim·Y. Ishida
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Abstract

We describe a compact and stable setup for detecting the optical second harmonics, in which the incident plane rotates with respect to the sample. The setup is composed of rotating Fresnel-rhomb optics and a femtosecond ytterbium-doped fiber-laser source operating at the repetition frequency of 10 MHz. The setup including the laser source occupies an area of 1 m2 and is stable so that the intensity fluctuation of the laser harmonics can be less than 0.2 % for 4 h. We present the isotropic harmonic signal of a gold mirror of 0.5 pW and demonstrate the integrity and sensitivity of the setup. We also show the polarization-dependent six-fold pattern of the harmonics of a few-layer WSe2, from which we infer the degree of local-field effects. Finally, we describe the extendibility of the setup to investigate the samples in various conditions such as cryogenic, strained, ultrafast non-equilibrium, and high magnetic fields.

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S. H. Kim, S. Jung, B. Seok, Y. S. Kim, H. Park, T. Otsu, Y. Kobayashi, C. Kim, Y. Ishida. 2021-04-22. A compact and stable incidence-plane-rotating second harmonics detector. https://doi.org/10.1063/5.0047337

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