All-Optical Light Field Sampling via Reflectivity Modulation
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Solution Overview
Problem
Current technologies are unable to directly measure the temporal profile of oscillations of the optical field in real time, specifically for non-electrically-conducting materials, which limits the observation of electron motion induced by strong few-optical-field-cycles-containing pulses.
Innovation Solution
An apparatus and method that utilize a light-divider system to split an input beam into drive and probe beams, with the drive beam modifying the target material's optical properties and the probe beam acquiring and measuring the resulting reflectivity or transmissivity changes with femtosecond or attosecond temporal resolution, allowing for real-time imaging of the optical field's temporal profile without phase-extraction algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If strong field interaction with thin dielectric films is used to generate wideband coherent EUV radiation, then the bandwidth of coherent radiation is improved, but the temporal resolution for measuring optical field oscillations deteriorates
Solution Approach 1:
The input beam is divided into two separate beams: a drive beam that interacts with the dielectric film to generate EUV radiation, and a probe beam that measures the optical field oscillations. This segmentation allows independent optimization of bandwidth generation and temporal resolution measurement without mutual interference.
Solution Approach 2:
A thin dielectric film (SiO2) is used as an intermediary medium that responds to the drive beam by generating EUV radiation while simultaneously modulating its optical properties (reflectivity) in response to the optical field oscillations. This intermediary enables the probe beam to detect temporal profiles with high precision while the drive beam provides broadband radiation.
2Measurement precision
If phase-extraction algorithms are used to retrieve temporal profiles, then the measurement capability is improved, but the complexity of the measurement system increases
Solution Approach 1:
The dielectric film's optical properties (reflectivity) automatically modulate in response to the optical field oscillations, directly encoding the temporal profile information into the probe beam's intensity. This self-service mechanism eliminates the need for complex phase-extraction algorithms, as the temporal profile is directly observable through simple intensity measurements.
3Duration of action of moving object
If femtosecond duration pulses are used, then the temporal resolution is improved, but the ability to resolve attosecond electron dynamics deteriorates
Solution Approach 1:
The probe beam measures the optical field oscillations at multiple discrete time delays, sampling the periodic oscillation pattern. By collecting data at multiple phases of the optical cycle and reconstructing the temporal profile from these periodic samples, attosecond electron dynamics can be resolved even though individual pulses have femtosecond duration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables direct, real-time measurement of the modulation of reflectivity and dielectric constant of non-electrically-conducting materials, providing attosecond temporal resolution and allowing for control of electron motion in dielectric materials, thereby facilitating advanced metrology and potential applications in ultrafast electronics and photonics.
Implementation Method 1
The strong field interaction induces a current in dielectric nanocircuit as was demonstrated, for example, by A. Schiffrin et al. (in Optical-field-induced current in dielectrics; Nature 493, 70-74; 2013)
Implementation Method 2
FIG. 1A schematically illustrate light-field induced carrier excitation mechanism
Implementation Method 3
In strong light field the dielectric material experience a phase transition and change in reflectivity following the field of the pulsed radiation impinging on such material
Implementation Method 4
modulation of reflectivity and dielectric constant of non-electrically-conducting materials
Data Source
AI summary
System and method configured for real-time, direct, all-optical methodology of measurement of a temporal profile of optical field. In one case, such measurement is carried out by recording electronic delay response of a target material system triggered by a strong driving optical field (in particular—by pulsed light with sub-femtosecond pulses containing a few cycles of optical field each). A corresponding all-optical metrological tool configured to operate with (sub-)femtosecond resolution. Demonstration of the on-demand sub-femtosecond electron motion control in solid-state with the use of synthesized waveforms of optical field.