Generation and detection of ultrabroadband infrared wave exceeding 200 THz

Abstract

By focusing a hollow-fiber compressed intense 10-fs pulse and its second harmonic in air, an ultrabroadband infrared pulse with a spectral range of 1-200 THz is generated through a plasma. Coherent detection of the signal up to 100 THz is achieved with electro-optic sampling and THz air-breakdown-coherent- detection. The drastic dependence on the orientation of the second harmonic crystal is clarified in a range of 100-200 THz. From these, the whole frequency components are confirmed to be generated from the AC biased plasma and phase-locked. © Owned by the authors, published by EDP Sciences, 2013.