E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Two-Photon Absorption Materials"

A special issue of Materials (ISSN 1996-1944).

Deadline for manuscript submissions: closed (30 November 2016)

Special Issue Editor

Guest Editor
Prof. Qing-Hua Xu

Department of Chemistry, National University of Singapore Singapore 117548, Singapore
Website | E-Mail

Special Issue Information

Dear Colleagues,

Two-photon absorption is a nonlinear optical process, which was originally predicted by Maria Goeppert-Mayer in 1931 in her doctoral dissertation. The first experimental verification of two-photon absorption became possible only after the invention of the laser, thirty years later. Due to its characteristic nature of three-dimensional confined excitation, two-photon absorption has found many applications in microscopy, microfabrication, data-storage, and biomedical applications. Two-photon absorption is particularly useful in biomedical applications due to the large biological penetration depth of the near-infrared light used in the two-photon excitation process. However, typical small molecules generally have very small two-photon absorption cross-sections. Initiation of two-photon absorption process requires very high laser power, which may cause adverse effects to biological species in two-photon based applications. Development of materials with large two-photon absorption cross sections are highly demanded for their various applications. The rapid advances in the materials design and synthesis, nanotechnology, development of pulsed laser technology have greatly vitalized this field. Lots of two-photon absorption materials have been designed and many two-photon absorption based applications have been developed.

This Special Issue aims to cover the most recent progress in the design and synthesis of inorganic, organic, polymer and nanomaterials with large two-photon absorption cross sections, as well as new applications of these materials in various two-photon based applications. It is my great pleasure to invite you to submit original full papers and communications, full and mini-reviews to this Special Issue.

Prof. Qing-Hua Xu
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1500 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Two-photon absorption
  • Two-photon microscopy
  • Two-photon imaging
  • Two-photon sensing
  • Two-photon photodynamic therapy
  • Two-photon drug-delivery
  • Optical limiting
  • Microfabrication
  • Nanomaterials

Published Papers (6 papers)

View options order results:
result details:
Displaying articles 1-6
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Femtosecond Two-Photon Absorption Spectroscopy of Poly(fluorene) Derivatives Containing Benzoselenadiazole and Benzothiadiazole
Materials 2017, 10(5), 512; doi:10.3390/ma10050512
Received: 19 January 2017 / Revised: 19 April 2017 / Accepted: 28 April 2017 / Published: 7 May 2017
PDF Full-text (1801 KB) | HTML Full-text | XML Full-text
Abstract
We have investigated the molecular structure and two-photon absorption (2PA) properties relationship of two push–pull poly(fluorene) derivatives containing benzoselenadiazole and benzothiadiazole units. For that, we have used the femtosecond wavelength-tunable Z-scan technique with a low repetition rate (1 kHz) and an energy per
[...] Read more.
We have investigated the molecular structure and two-photon absorption (2PA) properties relationship of two push–pull poly(fluorene) derivatives containing benzoselenadiazole and benzothiadiazole units. For that, we have used the femtosecond wavelength-tunable Z-scan technique with a low repetition rate (1 kHz) and an energy per pulse on the order of nJ. Our results show that both 2PA spectra present a strong 2PA (around 600 GM (1 GM = 1 × 10−50 cm4·s·photon−1)) band at around 720 nm (transition energy 3.45 eV) ascribed to the strongly 2PA-allowed 1Ag-like → mAg-like transition, characteristic of poly(fluorene) derivatives. Another 2PA band related to the intramolecular charge transfer was also observed at around 900 nm (transition energy 2.75 eV). In both 2PA bands, we found higher 2PA cross-section values for the poly(fluorene) containing benzothiadiazole unit. This outcome was explained through the higher charge redistribution at the excited state caused by the benzothiadiazole group as compared to the benzoselenadiazole and confirmed by means of solvatochromic Stokes shift measurements. To shed more light on these results, we employed the sum-over-states approach within the two-energy level model to estimate the maximum permanent dipole moment change related to the intramolecular charge transfer transition. Full article
(This article belongs to the Special Issue Two-Photon Absorption Materials)
Figures

Open AccessFeature PaperArticle Observation of Distinct Two-Photon Transition Channels in CdTe Quantum Dots in a Regime of Very Strong Confinement
Materials 2017, 10(4), 363; doi:10.3390/ma10040363
Received: 20 January 2017 / Revised: 21 March 2017 / Accepted: 23 March 2017 / Published: 30 March 2017
PDF Full-text (1016 KB) | HTML Full-text | XML Full-text
Abstract
We report here on the direct observation of distinct two-photon transition channels in glutathione-capped (GSH) CdTe quantum dots (QDs) in a very strong confinement regime. CdTe-GSH QDs with different average diameters (2.5, 3.0, and 3.3 nm) were synthesized through the one-pot method and
[...] Read more.
We report here on the direct observation of distinct two-photon transition channels in glutathione-capped (GSH) CdTe quantum dots (QDs) in a very strong confinement regime. CdTe-GSH QDs with different average diameters (2.5, 3.0, and 3.3 nm) were synthesized through the one-pot method and their two-photon absorption (2PA) spectrum determined by a femtosecond wavelength-tunable Z-scan. Our results show that the two lower-energy one-photon-allowed excitonic transitions, 1S3/2(h) → 1S(e) and 2S3/2(h) → 1S(e), are also accessed via 2PA. These results were ascribed to the relaxation of the parity selection rules due to the noncentrosymmetric structure of the CdTe QDs (zinc-blended structure), whose magnitude are determined by surface defects and structural irregularities present in CdTe-GSH QDs, in the strong confinement regime. Full article
(This article belongs to the Special Issue Two-Photon Absorption Materials)
Figures

Open AccessArticle Tunable Broadband Nonlinear Optical Properties of Black Phosphorus Quantum Dots for Femtosecond Laser Pulses
Materials 2017, 10(2), 210; doi:10.3390/ma10020210
Received: 6 January 2017 / Revised: 13 February 2017 / Accepted: 16 February 2017 / Published: 21 February 2017
Cited by 1 | PDF Full-text (2605 KB) | HTML Full-text | XML Full-text
Abstract
Broadband nonlinear optical properties from 500 to 1550 nm of ultrasmall black phosphorus quantum dots (BPQDs) have been extensively investigated by using the open-aperture Z-scan technique. Our results show that BPQDs exhibit significant nonlinear absorption in the visible range, but saturable absorption in
[...] Read more.
Broadband nonlinear optical properties from 500 to 1550 nm of ultrasmall black phosphorus quantum dots (BPQDs) have been extensively investigated by using the open-aperture Z-scan technique. Our results show that BPQDs exhibit significant nonlinear absorption in the visible range, but saturable absorption in the near-infrared range under femtosecond excitation. The calculated nonlinear absorption coefficients were found to be (7.49 ± 0.23) × 10−3, (1.68 ± 0.078) × 10−3 and (0.81 ± 0.03) × 10−3 cm/GW for 500, 700 and 900 nm, respectively. Femtosecond pump-probe measurements performed on BPQDs revealed that two-photon absorption is responsible for the observed nonlinear absorption. The saturable absorption behaviors observed at 1050, 1350 and 1550 nm are due to ground-state bleaching induced by photo-excitation. Our results suggest that BPQDs have great potential in applications as broadband optical limiters in the visible range or saturable absorbers in the near-infrared range for ultrafast laser pulses. These ultrasmall BPQDs are potentially useful as broadband optical elements in ultrafast photonics devices. Full article
(This article belongs to the Special Issue Two-Photon Absorption Materials)
Figures

Figure 1

Open AccessArticle Energy Donor Effect on the Sensing Performance for a Series of FRET-Based Two-Photon Fluorescent Hg2+ Probes
Materials 2017, 10(2), 108; doi:10.3390/ma10020108
Received: 29 December 2016 / Revised: 18 January 2017 / Accepted: 22 January 2017 / Published: 25 January 2017
PDF Full-text (2843 KB) | HTML Full-text | XML Full-text
Abstract
Nonlinear optical properties of a series of newly-synthesized molecular fluorescent probes for Hg2+ containing the same acceptor (rhodamine group) are analyzed by using time-dependent density functional theory in combination with analytical response theory. Special emphasis is placed on evolution of the probes’
[...] Read more.
Nonlinear optical properties of a series of newly-synthesized molecular fluorescent probes for Hg2+ containing the same acceptor (rhodamine group) are analyzed by using time-dependent density functional theory in combination with analytical response theory. Special emphasis is placed on evolution of the probes’ optical properties in the absence and presence of Hg2+. These compounds show drastic changes in their photoabsorption and photoemission properties when they react with Hg2+, indicating that they are excellent candidates for ratiometric and colorimetric fluorescent chemosensors. Most importantly, the energy donor moiety is found to play a dominant role in sensing performance of these probes. Two-photon absorption cross sections of the compounds are increased with the presence of Hg2+, which theoretically suggests the possibility of the probes to be two-photon fluorescent Hg2+ sensors. Moreover, analysis of molecular orbitals is presented to explore responsive mechanism of the probes, where the fluorescence resonant energy transfer process is theoretically demonstrated. Our results elucidate the available experimental measurements. This work provides guidance for designing efficient two-photon fluorescent probes that are geared towards biological and chemical applications. Full article
(This article belongs to the Special Issue Two-Photon Absorption Materials)
Figures

Figure 1

Open AccessArticle The Effect of the Substituent Position on the Two-Photon Absorption Performances of Dibenzylideneacetone-Based Isomers
Materials 2016, 9(12), 1026; doi:10.3390/ma9121026
Received: 31 October 2016 / Revised: 6 December 2016 / Accepted: 14 December 2016 / Published: 20 December 2016
PDF Full-text (1252 KB) | HTML Full-text | XML Full-text
Abstract
The two-photon absorption and optical limiting properties of two dibenzylideneacetone derivatives with different substituent positions have been theoretically investigated by solving the coupled rate equations-field intensity equation in the nanosecond time domain using an iterative predictor-corrector finite-difference time-domain method. The calculations show that
[...] Read more.
The two-photon absorption and optical limiting properties of two dibenzylideneacetone derivatives with different substituent positions have been theoretically investigated by solving the coupled rate equations-field intensity equation in the nanosecond time domain using an iterative predictor-corrector finite-difference time-domain method. The calculations show that the electronic structure, the transition dipole moment, the energy gap between the highest occupied orbital (HOMO) and the lowest unoccupied orbital (LUMO), and the pumping rate for the two molecules are quite different due to the different position of chlorine atoms. Importantly, two-photon absorption and optical limiting properties of the molecules depend crucially on the substituent positions of the terminal group, indicating that subtle manipulation on the molecule can affect the nonlinear optical properties of the medium. Full article
(This article belongs to the Special Issue Two-Photon Absorption Materials)
Figures

Figure 1

Review

Jump to: Research

Open AccessReview Lighting the Way to See Inside Two-Photon Absorption Materials: Structure–Property Relationship and Biological Imaging
Materials 2017, 10(3), 223; doi:10.3390/ma10030223
Received: 25 November 2016 / Accepted: 16 February 2017 / Published: 23 February 2017
Cited by 2 | PDF Full-text (9639 KB) | HTML Full-text | XML Full-text
Abstract
The application of two-photon absorption (2PA) materials is a classical research field and has recently attracted increasing interest. It has generated a demand for new dyes with high 2PA cross-sections. In this short review, we briefly cover the structure-2PA property relationships of organic
[...] Read more.
The application of two-photon absorption (2PA) materials is a classical research field and has recently attracted increasing interest. It has generated a demand for new dyes with high 2PA cross-sections. In this short review, we briefly cover the structure-2PA property relationships of organic fluorophores, organic-inorganic nanohybrids and metal complexes explored by our group. (1) The two-photon absorption cross-section (δ) of organic fluorophores increases with the extent of charge transfer, which is important to optimize the core, donor-acceptor pair, and conjugation-bridge to obtain a large δ value. Among the various cores, triphenylamine appears to be an efficient core. Lengthening of the conjugation with styryl groups in the D-π-D quadrupoles and D-π-A dipoles increased δ over a long wavelength range than when vinylene groups were used. Large values of δ were observed for extended conjugation length and moderate donor-acceptors in the near-IR wavelengths. The δ value of the three-arm octupole is larger than that of the individual arm, if the core has electron accepting groups that allow significant electronic coupling between the arms; (2) Optical functional organic/inorganic hybrid materials usually show high thermal stability and excellent optical activity; therefore the design of functional organic molecules to build functional organic-inorganic hybrids and optimize the 2PA properties are significant. Advances have been made in the design of organic-inorganic nanohybrid materials of different sizes and shapes for 2PA property, which provide useful examples to illustrate the new features of the 2PA response in comparison to the more thoroughly investigated donor-acceptor based organic compounds and inorganic components; (3) Metal complexes are of particular interest for the design of new materials with large 2PA ability. They offer a wide range of metals with different ligands, which can give rise to tunable electronic and 2PA properties. The metal ions, including transition metals and lanthanides, can serve as an important part of the structure to control the intramolecular charge-transfer process that drives the 2PA process. As templates, transition metal ions can assemble simple to more sophisticated ligands in a variety of multipolar arrangements resulting in interesting and tailorable electronic and optical properties, depending on the nature of the metal center and the energetics of the metal-ligand interactions, such as intraligand charge-transfer (ILCT) and metal-ligand charge-transfer (MLCT) processes. Lanthanide complexes are attractive for a number of reasons: (i) their visible emissions are quite long-lived; (ii) their absorption and emission can be tuned with the aid of appropriate photoactive ligands; (iii) the accessible energy-transfer path between the photo-active ligands and the lanthanide ion can facilitate efficient lanthanide-based 2PA properties. Thus, the above materials with excellent 2PA properties should be applied in two-photon applications, especially two-photon fluorescence microscopy (TPFM) and related emission-based applications. Furthermore, the progress of research into the use of those new 2PA materials with moderate 2PA cross section in the near-infrared region, good Materials 2017, 10, 223 2 of 37 biocompatibility, and enhanced two-photon excited fluorescence for two-photon bio-imaging is summarized. In addition, several possible future directions in this field are also discussed (146 references). Full article
(This article belongs to the Special Issue Two-Photon Absorption Materials)
Figures

Figure 1

Journal Contact

MDPI AG
Materials Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
E-Mail: 
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Materials Edit a special issue Review for Materials
logo
loading...
Back to Top