Third harmonic generation due to free carrier in InSb using a terahertz free electron laser
Thanh Nhat Khoa Phan, Tomoki Shimizu, You Wei Wang, Kosaku Kato, Verdad C. Agulto, Goro Isoyama, Shinsuke Fujioka, Makoto Nakajima
Abstract
We report on the third harmonic generation (THG) in InSb semiconductor irradiated by a terahertz (THz) free electron laser (FEL). The conversion of 4 THz (wavelength 70 µm) FEL outputs into its third harmonic 12 THz was observed. We found that by tuning the sample temperature to 360 K, high conversion efficiency up to 1% can be obtained and is the highest in the THz and FIR regions below 10 THz. We also discuss the observed intensity dependence of the THG with the nonlinear order lower than 3 when the pumping intensity was high.
Topics & Concepts
Terahertz radiationFree-electron laserLaserOpticsMaterials scienceHigh harmonic generationFree electron modelFar-infrared laserOptoelectronicsSemiconductorTerahertz spectroscopy and technologyEnergy conversion efficiencyWavelengthSecond-harmonic generationFree carrierNonlinear opticsPhotomixingPhysicsTerahertz metamaterialsPhotonic and Optical DevicesTerahertz technology and applicationsSpectroscopy and Laser Applications