Source noise suppression in attosecond transient absorption spectroscopy by edge-pixel referencing.

Area of Science:

• Ultrafast spectroscopy
• Materials science
• Quantum dynamics

Background:

• Attosecond transient absorption spectroscopy (ATAS) offers exceptional time resolution for observing photoexcited dynamics.
• Instabilities in high-harmonic generation sources limit ATAS sensitivity.
• Existing methods struggle to overcome noise inherent in ATAS experiments.

Purpose of the Study:

• To introduce novel edge-pixel referencing methods for noise suppression in ATAS.
• To enhance the sensitivity and reliability of ATAS measurements.
• To provide a robust solution applicable to both real-time data and existing datasets.

Main Methods:

• Development of two edge-pixel referencing approaches: deterministic correlation analysis and singular value decomposition.
• Application and quantification of these methods on a noisy WS2 measurement.
• Demonstration of noise reduction and sensitivity enhancement.

Main Results:

• A fivefold increase in sensitivity was achieved using edge-pixel referencing techniques.
• The proposed methods effectively suppress noise, bringing ATAS sensitivity close to the detector noise floor.
• The fidelity of the procedure was confirmed, showing applicability to live data and historical data.

Conclusions:

• Edge-pixel referencing is a powerful strategy to overcome sensitivity limitations in ATAS.
• The developed methods significantly improve the performance of ATAS for studying ultrafast phenomena.
• This work provides practical tools and insights for advancing attosecond spectroscopy.