Resonant two- or three-photon ionization of noble-gas atoms captured by time-resolved photoelectron momentum spectroscopy

Murakami, M; Zhang, GP / PHYSICAL REVIEW A (2017) / DOI: https://doi.org/10.1103/PhysRevA.96.063403

Overview

We present an all-electron, ab initio calculation of time-resolved photoelectron momentum distributions (PMDs) induced by resonant two-color, two-or three-photon ionization of helium and neon atoms, as recently measured by Villeneuve et al. [Science 356, 1150 (2017)] using a femtosecond infrared (IR) laser pulse and an attosecond pulse train (APT) produced with high harmonic generation as an extreme ultraviolet (XUV) photon source. In contrast to a monochromatic XUV pulse commonly used at the free-electron laser facilities, an APT is broadband and ultrashort (< 1 fs), so that it could induce n

Key Points

• 1. Excitation scheme & wavelength design
• 2. Pulse energy and delay tuning
• 3. Balancing selectivity and ionization efficiency

Design & Function

• Design: Optimize multistep resonance scheme and optics
• Function: Evaluate ion signal, S/N and resolution
• Feature: Parameter optimization for wavelength/energy/delays

Mini Glossary

• R3PI — Resonance-enhanced three-photon ionization
• REMPI — Resonance-enhanced multiphoton ionization

References

1. PHYSICAL REVIEW A (2017). DOI: https://doi.org/10.1103/PhysRevA.96.063403

Resonant two- or three-photon ionization of noble-gas atoms captured by time-resolved photoelectron momentum spectroscopy

Murakami, M; Zhang, GP / PHYSICAL REVIEW A (2017) / DOI: https://doi.org/10.1103/PhysRevA.96.063403

概要 / Overview

R3PI/REMPI を用いたレーザー分光・イオン化計測の最適化。励起準位設計や波長・パルス条件の最適化により、選択性と感度（S/N）を改善しました。

ここがポイント / Key Points

• 1. 励起スキーム/波長設計
• 2. パルスエネルギー・遅延チューニング
• 3. 選択性とイオン化効率の両立

設計と機能 / Design & Function

• 設計：多段励起（選択則・中間準位）と光学系の最適化
• 機能：イオン信号・S/N・分解能の評価
• 特長：波長/エネルギー/遅延のパラメトリック最適化

用語ミニ解説 / Mini Glossary

• R3PI：共鳴三光子イオン化（Resonance-enhanced three-photon ionization）
• REMPI：共鳴多光子イオン化（Resonance-enhanced multiphoton ionization）

参考文献 / References

1. PHYSICAL REVIEW A (2017). DOI: https://doi.org/10.1103/PhysRevA.96.063403