Abstract-Terahertz Generation by Optical Rectification in Sugar Crystal

 

Federico Sanjuan, Gwenaël Gaborit, Jean-Louis Coutaz,

https://link.springer.com/article/10.1007/s10762-021-00795-6

We report on THz pulse generation through optical rectification of femtosecond laser pulses in sugar crystals. The sugar crystals were grown from an aqueous solution of caster cane sugar bought in a local grocery. Sugar exhibits rather good nonlinear coefficients (d23≃56$d_{23}\simeq 56$ pm/V), but the optical-THz conversion efficiency remains quite weak because of the lack of phase-matching, when pumped by a laser beam of 0.8-μm central wavelength. Nevertheless, sugar availability at a low price makes it a relevant material for trial experiments.

Abstract-Full electro-optic terahertz time-domain spectrometer for polarimetric studies

Federico Sanjuan, Gwenaël Gaborit, and Jean-Louis Coutaz

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-57-21-6055

We present a terahertz (THz) time-domain spectrometer dedicated to polarimetric studies. THz pulses are generated through optical rectification in a ⟨111⟩$⟨111⟩$-cut cubic crystal. The ⟨111⟩$⟨111⟩$ crystal cut produces a THz polarization state similar to that of the exciting laser beam. Detection of the THz pulses is performed by electro-optic sampling in a similar crystal, and a dual detection scheme allows us to measure simultaneously the two polarization components of the THz beam. We experimentally illustrate that the polarization of the THz beam can be adjusted by adjusting the laser polarization. This technique alleviates the need for a polarization controller at THz frequencies.

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