Ultrafast Quantum Optics: Generation, Attosecond Control, and Applications of Broadband Squeezed Light
Mohamed Sennary
Abstract
Nonclassical states of light are central resources for quantum metrology and quantum information, yet most high performance squeezing platforms operate in narrowband or continuous-wave regimes where the quantum noise is effectively stationary. This work advances ultrafast quantum optics by demonstrating how squeezed states can be generated, measured, and engineered on femtosecond and attosecond time scales, so that quantum fluctuations become a controllable property of the optical waveform itself. In this work, broadband few-cycle coherent drivers are produced using the light field synthesizer (LFS) setup that coherently combines UV/VIS/NIR channels with independently adjustable delays and amplitudes. Ultrafast squeezed light is generated via degenerate four-wave mixing (DFWM) in fused silica using a three-beam interaction geometry, implemented as a quantum light field squeezer (QLFS) that enables quasi-collinear phase matching across a wide bandwidth. A metrology framework compatible with ultrashort pulses is developed: amplitude (intensity) uncertainty is extracted from shot-to-shot spectral statistics, while relative phase fluctuations are retrieved from spectral-interference fringes in channel-overlap regions. These observables are connected to a displaced squeezed state model by fitting variance expressions, enabling phase-space visualization through Wigner function reconstruction. Beyond static squeezing, the QLFS provides attosecond-resolved control of the generated quantum state by tuning inter-pulse delay and phase matching geometry, allowing the redistribution of uncertainty between conjugate quadratures and revealing time-dependent (sub-cycle) structure of the intensity uncertainty within the optical cycle. Finally, the work extends ultrafast quantum optics into solid-state systems by demonstrating squeezed light driven tunneling in a graphene-silicon-graphene phototransistor, where state-dependent modulation of current noise is observed alongside simultaneous optical uncertainty measurements. Together, these results establish a practical route to waveform-level quantum state engineering and motivate future ultrafast quantum metrology, strong field quantum optics control, and hybrid photonic electronic quantum technologies.