[17p-W9_326-1~16] 3.5 Ultrashort-pulse and high-intensity lasers

6:00 PM - 6:15 PM JST(9:00 AM - 9:15 AM UTC)English Presentation

[17p-W9_326-16] Alloharmonics in BISER (Burst Intensification by Singularity Emitting Radiation)

〇Alexander S Pirozhkov¹, K. Ogura¹, M. S. Pirozhkova¹, A. Sagisaka¹, T. Zh. Esirkepov¹, A. Ya. Faenov², T. A. Pikuz^2,3, H. Kotaki¹, Y. Hayashi¹, Y. Fukuda¹, J. K. Koga^1,4, S. V. Bulanov^1,5, H. Daido², N. Hasegawa¹, M. Ishino¹, M. Nishikino¹, M. Koike¹, T. Kawachi¹, H. Kiriyama¹, D. Neely^6,7, M. Kando¹ (1.QST, 2.Osaka Univ., 3.Inst. Laser Tech., 4.Kyoto Int. Univ Acad, 5.ELI-Beamlines, 6.RAL, 7.Univ. Strathclyde)

Keywords:

Nonperiodic nonlinear processes,Relativistic laser plasma,Coherent x-ray sources

We resolve a long-standing puzzle concerning anomalous spectral fringes observed in coherent XUV radiation from the Burst Intensification by Singularity Emitting Radiation (BISER) mechanism [PRL 108, 135004 (2012); Scientific Reports 7, 17968 (2017); J. Plasma and Fusion Research (accepted)]. We demonstrate that these fringes arise from alloharmonics, i.e. spectral interference of different harmonic orders in nonperiodic processes [arXiv:2306.01018 (2024); arXiv:2506.23548 (2025)]. This fundamental insight, validated by matched experimental data and analytical theory and data statistics, allows precise parameter extraction from the data. Alloharmonics is a general physical principle extending beyond BISER, explaining and predicting phenomena in fields as diverse as relativistic laser plasma, pulsar radio waves, and gravitational waves from blackhole mergers.