Work

Measurement of the Entangled Two‐Photon Absorption Cross‐Sections of 4‐Aminoazobenzene

Year: 2026

Type: article

Abstract: Recently, entangled two‐photon absorption (ETPA) has attracted considerable attention, yet reported cross‐sections vary widely. In this study, we focused on 4‐aminoazobenzene, an azobenzene derivative that exhibits extremely low one‐photon absorption in the wavelength range of time‐entangled photon pairs. By measuring the time correlation between the two photons transmitted through the sample solution and separating correlated from uncorrelated counts, we distinguished between ETPA and linear‐loss contributions. The ETPA cross‐section is only ≈10 7 ‐fold lower than the one‐photon absorption cross‐section and ≈10 18 ‐fold higher than the classical TPA cross‐section (evaluated under classical two‐photon excitation at a photon‐flux density of ≈10 8 photons·s –1 ·cm –2 ). Moreover, ETPA is measurable at a photon‐flux density of ≈10 8 photons·s –1 ·cm –2 .

Source: ChemPhysChem

DOI: 10.1002/cphc.70403

Authors: Sena Hashimoto, Hisaki Oka, Izumi Iwakura, Tomoyuki Horikiri

Institutions: Japan Society for the Promotion of Science, Kanagawa University, Yokohama National University

Language: English

Topic: Nonlinear Optical Materials Studies

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,550

Funders: Kanagawa University, Japan Society for the Promotion of Science