We propose a method to measure the temporal phase of ultrashort pulsed squeezed vacuum. We verified that the temporal chirp has limited influence on pulsed squeezing level.
The pulsed squeezed state of light is expected to enhance the sensitivity of optical measurements using optical pulses. To achieve a high squeezing level, it is crucial to explore its limiting factors. In this study, we analyze the pulsed squeezed vacuum detected with picosecond pulses to explore two critical factors that limit the achievable squeezing level. First, we investigate the effect of the frequency chirp of local oscillator (LO) pulses and show that there exists an upper bound of the chirp parameter for a given squeezing level. Next, we analyze the effect of temporal matching between the LO pulse and the squeezed vacuum and point out the importance of temporal broadening in nonlinear optical crystals for squeezing.
Bright squeezed vacuum (BSV) takes the phenomenon of squeezed vacuum to the extreme [1]. Extremely high photon numbers of up to 1013can be found inside a single BSV pulse due to the antisqueezed quadrature, with effective pulse durations down to tens of femtoseconds [2]. BSV is sufficiently intense to drive nonperturbative HHG from solids [2] and multiphoton electron emission from nanotips [3]. Intriguingly, BSV has the potential to explore sub-cycle light-matter interactions above the conventional damage threshold [2]. However, characterizing the full temporal properties (mean and distribution) of BSV pulses has remained elusive. Here we overcome this challenge by full temporal characterization (amplitude and phase) of single-shot BSV pulses, for the first time.