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José Habib Moraes F, Torres Coimbra de Sá Balbina F, Procópio Alves L, Uchoa Fernandes A, Munin E. Avalanche-assisted transient optical phenomenon in aggregated toluidine blue dye. Spectrochim Acta A Mol Biomol Spectrosc 2024; 315:124291. [PMID: 38643559 DOI: 10.1016/j.saa.2024.124291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 03/18/2024] [Accepted: 04/12/2024] [Indexed: 04/23/2024]
Abstract
Pulse-modulated CW laser heat deposition modulates the darkness or the transparency of an aggregated medium in the high signal optical regimen. A recently reported work found that transient optical responses of molecular aggregates can be different depending on whether the sample is excited with a laser wavelength tuned within the absorption band of the monomer or within the absorption band of the aggregates. The different transient responses were attributed to different dynamic processes during the laser-induced disassembling of the molecular aggregates and may have implications in the field of organic electronics and optical devices, such as optical logical gates, optical power limiters and all-optical switching. In this paper laser beams with wavelengths of 663 nm and 532 nm were used to produce sudden changes in the thermodynamic equilibrium of the aggregation states of the ortho-toluidine blue dye, which allowed to observe the occurrence of the avalanche - mediated transient phenomenon in the laser-induced disassembling of ortho-toluidine blue (TBO) aggregates. A double exponential model was adjusted to the registered transient data. The obtained values for the fast components of the transient time responses of ortho-toluidine blue dye, for the studied concentrations, ranged from ∼ 6.5 to 9.5 ms at 532 nm, and from ∼ 43 to 48 ms at 663 nm. A single beam experiment was employed to evaluate the performance of the ortho-toluidine blue dye in a beam power-damping device, driven by the simultaneous and cooperative actions of the laser induced disassembling of aggregated dye units and the thermal lensing effect. It was found that the phenomenon of laser-induced dye disassembling of TBO, acting cooperatively with the thermal lensing effect, damps the laser beam power faster than the thermal lensing phenomenon alone. In addition, the results showed that the speed of the laser beam power-damping is dye dependent.
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Affiliation(s)
- Fernando José Habib Moraes
- Center for Biomedical Engineering, Anhembi Morumbi University (UAM), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil
| | | | - Leandro Procópio Alves
- Center for Biomedical Engineering, Anhembi Morumbi University (UAM), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil; Center of Innovation, Technology and Education (CITE), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil
| | - Adjaci Uchoa Fernandes
- Center for Biomedical Engineering, Anhembi Morumbi University (UAM), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil; Center of Innovation, Technology and Education (CITE), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil
| | - Egberto Munin
- Center of Innovation, Technology and Education (CITE), Rodovia Dr Altino Bondensan 500, São José dos Campos 12247-016, SP, Brazil.
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Borges FDS, Moraes FJH, Pereira Neto MA, d'Almeida JRM, Bento AC, Cella N. Photoacoustic spectroscopy applied in the monitoring of photocuring process in epoxy diacrylate resins: Positive effect. POLYM ADVAN TECHNOL 2022. [DOI: 10.1002/pat.5864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Francis de Souza Borges
- Instituto Politécnico, IPRJ Universidade do Estado do Rio de Janeiro, UERJ Nova Friburgo RJ Brazil
| | | | | | - José Roberto Moraes d'Almeida
- Departamento de Engenharia Química e de Materiais Pontifícia Universidade Católica do Rio de Janeiro, PUC‐Rio Rio de Janeiro RJ Brazil
| | | | - Norberto Cella
- Instituto Politécnico, IPRJ Universidade do Estado do Rio de Janeiro, UERJ Nova Friburgo RJ Brazil
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