Dispersion Control of an Over-Octave Spanning Shortwave Infrared Spectrum for the Amplification of Single-Cycle Pulses

Abstract

Development on laser systems generating a single-cycle even a sub-optical-cycle pulse in an infrared (IR) region has become a worldwide trend in the research fields of ultrashort optics, since it opens up a number of advance research field in strong-field physics [1]. However, to realize such an ultrashort pulse, dispersion control of the over-octave bandwidth waveform is extremely challenging since ultrabroadband dispersive optics with high precision and damage threshold are required. Passive management, based on chirp dichroic mirrors [2], has been shown to support multi-octave bandwidth with high reflectivity. However, it is not adaptable once the dispersion condition is changed within the laser system. Active optics such as deformable mirrors (DM) [3] and spatial light modulator (SLM) [4] are also promising methods for pulse compression in preceding research. Nevertheless, group delay range for the DM is restricted to much less than ps, and birefringence of a conventional SLM is not sufficient to apply 2 π phase shift in IR region. These hamper their application in an over-octave bandwidth high-intensity laser system. More recently, acousto-optic programmable dispersive filter (AOPDF) [5,6] has become a strong candidate for dispersion control of high-intensity, few-cycle, shortwave infrared (SWIR) laser sources due to their robustness and accessibility. The main issue with AOPDF is that it cannot sustain an over-octave bandwidth.