Arbitrary CEP Manipulation for Spatiotemporal Control of Sub-cycle Optical Vortex

Intense few-cycle optical vortex (OV) sources are highly promising in strong-field applications such as high-order-harmonic generation, filamentation, and supercontinuum. The generation of such laser pulses is owing to the progress of the ultrafast amplifier technologies combined with achromatic methods for OV generation [1]–[3]. As the pulse duration becomes even shorter to the single or sub-cycle regimes, complete control of the spatiotemporal evolution of the electric field of a train of OV pulses will be beneficial for studying physical phenomena that depend directly on the electric field rather than the pulse intensity envelope. However, there is no experimental study discussing this matter due to the lack of accessibility to such a light source until now. In this work, we report on the realization of a carrier-envelope phase (CEP) controllable, over-octave bandwidth OV source with a wavelength range of 0.9-2.4 μm (short-wave infrared, SWIR) and a pulse duration of 4.7 fs, corresponding to 0.9 cycles at the carrier wavelength of 1.54 μm. We employ this light source to demonstrate the arbitrary CEP control for the manipulation of the spatiotemporal properties of sub-cycle OV pulses.