Direct Observation of the Gouy Phase Shift with Single-Cycle Terahertz Pulses

Abstract

We report a direct observation of the predicted polarity reversal due to the Gouy phase shift for single-cycle terahertz pulses passing through a focus.

Direct observation of the Gouy phase shift in THz impulse ranging

“…3 Recently, the importance of the Gouy phase shift to focused single-cycle electromagnetic pulses has been discussed, 4 and a direct observation of the Gouy phase shift through a spherical focus with THz pulses was reported. 5 As presented here, an understanding of the Gouy phase shift through a one-axis ͑cylin-drical͒ focus of /2 in comparison with a two-axis ͑spheri-cal͒ focus of is required to interpret the scattering results using a time domain physical optics ͑PO͒ model for scattering. 1,2,6 The physical optics model allows one to isolate and to understand the different physical mechanisms involved in the scattering process, which are not at all transparent in the often used and well known Mie scattering theory.…”

Wavefront spacing and Gouy phase in presence of primary spherical aberration

“…Recently, it has been theoretically investigated in a variety of applications, such as highnumerical aperture systems [10,11], nondiffracting beams [12,13], and partially coherent focused fields [14]. Experimental observations were reported in, e.g., [15][16][17][18][19][20][21]. A precise knowledge of the Gouy phase is crucial in a wide variety of metrological techniques.…”

Terahertz Focusing and Polarization Control in Large-Area Bias-Free Semiconductor Emitters

“…Experimentally, depending on the position of our emitter, we characterize the THz beam waist and find that the emitted THz radiation undergoes a Gouy phase shift [23][24][25][26]. As the electric field is detected in THz-TDS, the Gouy shift manifests as a polarity flip in the THz detected wavefront if the emitter is placed after the focus of the lens [27], further supporting the notion that the THz is being focused in the same place as the optical pump. The importance and use of the Gouy shift has been reported in the field of THz imaging [28][29][30][31][32][33][34][35][36].…”