Nonlinear Optical Crystals for Second Harmonic Generation

Solgi, S.; Tafreshi, Majid Jafar; Ghamsari, M. Sasani

doi:10.1134/s1063774519070204

Cited by 9 publications

(13 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unlike π-conjugated units, the tetrahedral units are rarely favored due to their weak optical nonlinearity for the design of deep-UV frequency-doubling crystals. For those constructed only by deep-UV transparent tetrahedra that have larger energy gaps, the possibility of electron transition between the conduction and valence bands is proportional to the inverse of the energy difference at each momentum point, thus such crystals should have weaker SHG effects . However, with a few exceptions, fully tetrahedra-based crystals can also show strong optical nonlinearity, such as BPO 4 and LaBeB 3 O 7 . , Faced with this, both theoretical and experimental studies have been performed to clarify the roles of deep-UV transparent tetrahedra in enhancing the SHG effects, and the following three approaches are proven to be effective and feasible: enhance the orbital hybridization of tetrahedral anionic groups; reduce the charge-transfer energy; and break the symmetry of the original tetrahedra with F atoms. …”

Section: Orbital Hybridization Enhancement Charge-transfer Energy Red...mentioning

confidence: 99%

“…For those constructed only by deep-UV transparent tetrahedra that have larger energy gaps, the possibility of electron transition between the conduction and valence bands is proportional to the inverse of the energy difference at each momentum point, thus such crystals should have weaker SHG effects. 35 However, with a few exceptions, fully tetrahedra-based crystals can also show strong optical nonlinearity, such as BPO 4 and LaBeB 3 O 7 . 36,37 Faced with this, both theoretical and experimental studies have been performed to clarify the roles of deep-UV transparent tetrahedra in enhancing the SHG effects, and the following three approaches are proven to be effective and feasible:…”

Section: Orbital Hybridization Enhancement Charge-transfer Energy Red...mentioning

confidence: 99%

See 1 more Smart Citation

Toward the Enhancement of Critical Performance for Deep-Ultraviolet Frequency-Doubling Crystals Utilizing Covalent Tetrahedra

2021

View full text Add to dashboard Cite

Metrics & MoreArticle Recommendations CONSPECTUS: Deep-ultraviolet (deep-UV, λ < 200 nm) coherent light is emerging as an indispensable driving force behind the innovation of optics and materials science. The deep-UV-driven applications range from laser interference photolithography to precise micromachining to futuristic ideas such as space propulsion using remotely controlled positioning lasers. Unlike conventional approaches to obtaining deep-UV light, for instance, synchrotron radiation, direct laser excitation, and gas discharge, nonlinear frequency conversion can be regarded as a more attractive way to endow such resource with high photon energy, high photon flux, and high spectral resolution. Actually, the nonlinear frequency conversion can be efficient only with the use of highperforming frequency-doubling crystals, which should be well-suited to the physics of nonlinear optical process. However, the necessary prerequisites for a practical frequency-doubling crystal are extremely strict, and thus very few crystals can be used to generate the deep-UV light.Faced with this, sustained effort has been expended by chemists and materials scientists toward discovering novel deep-UV frequency-doubling crystals. Studies have so far indicated that the main difficulty in finding a perfect candidate comes from the combination of three critical properties (absorption edge, nonlinear optical coefficients, and birefringence) into one crystal because they share the mutual relation of restriction and influence.In this Account, we present recent progress in discovering emergent deep-UV frequency-doubling crystals with the discussion of our efforts to balance the three critical properties by introducing the covalent tetrahedra [MO 4−n X n ] (n = 1−3), in which M refers to central atoms such as B, P, Si, S, Al, Zn, and Be and X can be apical atoms such as F, Cl, Br, and N. By analyzing the influence of the covalent tetrahedra on optical properties, we came to the conclusion of how to use the oxidized tetrahedra to achieve the improvement of the absorption edge, nonlinear optical coefficients, and birefringence for deep-UV frequency-doubling crystals. The followings are the key points in achieving the above goals: (i) elimination of dangling bonds with covalent tetrahedra to push the absorption edge of crystals into the deep-UV spectral region; (ii) orbital hybridization enhancement, charge-transfer energy reduction, and symmetry breaking of original tetrahedra with the introduction of X atoms and thereby the achievement of the enhancement of nonlinear optical coefficients; and (iii) uniform alignment of tetrahedral distorted units and the introduction of polarized X atoms containing [MO 4−n X n ] tetrahedra with high polarizability anisotropy to cause the large enhancement of birefringence. These findings allow us to understand the microcosmic behaviors of covalent tetrahedra on pushing the current limitations and provide an optional functional group toward the maximum thresholds of three critical parameters for deep-UV freq...

show abstract

Section: Orbital Hybridization Enhancement Charge-transfer Energy Red...mentioning

confidence: 99%

Section: Orbital Hybridization Enhancement Charge-transfer Energy Red...mentioning

confidence: 99%

Toward the Enhancement of Critical Performance for Deep-Ultraviolet Frequency-Doubling Crystals Utilizing Covalent Tetrahedra

2021

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5][6][7][8][9] In particular, a promising nonlinear optical crystal should exhibit several basic requirements including a large second-harmonic generation effect, wide bandgap and transmission ranges, a high laser-induced damage threshold value, a phase-matchable property, a facile preparation method, etc. [10][11][12][13][14][15] In the iodate anions (e.g. I V O 3 and I V O 4 ), the lone-pair electrons on the I 5+ cation induce a second-order Jahn-Teller distortion effect that causes giant microscopic acentricity.…”

Section: Introductionmentioning

confidence: 99%

“…1–9 In particular, a promising nonlinear optical crystal should exhibit several basic requirements including a large second-harmonic generation effect, wide bandgap and transmission ranges, a high laser-induced damage threshold value, a phase-matchable property, a facile preparation method, etc . 10–15…”

Section: Introductionmentioning

confidence: 99%

Ba₄Ag₅(IO₃)₆(I₃O₈)₃(I₄O₁₁)₂: a nonlinear optical crystal containing two types of polyiodate anions

Chen

Mao

et al. 2022

Inorg. Chem. Front.

View full text Add to dashboard Cite

show abstract

“…Among NLO properties the second harmonic generation (SHG) is certainly the most studied property. Designing organic materials with highest SHG activities is thus a very active research area [7]. Among polar crystals with their intrinsic asymmetry, natural amino acids offer very interesting avenues to explore as they are homochiral.…”

Section: Introductionmentioning

confidence: 99%

Polar and Helical Isomorphous Crystals of Proline Derivatives: Influence of a Fluorine Atom on the Electric Susceptibility

et al. 2021

View full text Add to dashboard Cite

Two novel nonlinear optical isomorphous crystals of proline derivatives with alkyne functionality have been obtained (Boc-L-ProNH(CH2)2CCH and Boc-cis-4-fluoro-L-ProNH(CH2)2CCH). Both derivatives, which differ only by the substitution of a H atom to a F atom, adopt the same polar and columnar right-handed helix arrangement in the crystalline state. In addition, adjacent polar helical columns all point in the same direction, thus generating a macrodipole and a crystalline system conducive for second harmonic generation (SHG) properties. This isomorphous crystal system constitutes an interesting tool to study the effect of the fluorine atom on the dipole moment and on the first hyperpolarizability. Starting from the PBC optimized geometries of the crystals, the macroscopic second-order nonlinearity, χ(2), of the newly synthesized crystals has been estimated by quantum chemical calculations. These χ(2) responses are of the same order of magnitude as those of inorganic proline derivatives while smaller than those observed in crystals of push–pull π-conjugated molecules. Graphic Abstract

show abstract

Nonlinear Optical Crystals for Second Harmonic Generation

Cited by 9 publications

References 69 publications

Toward the Enhancement of Critical Performance for Deep-Ultraviolet Frequency-Doubling Crystals Utilizing Covalent Tetrahedra

Toward the Enhancement of Critical Performance for Deep-Ultraviolet Frequency-Doubling Crystals Utilizing Covalent Tetrahedra

Ba₄Ag₅(IO₃)₆(I₃O₈)₃(I₄O₁₁)₂: a nonlinear optical crystal containing two types of polyiodate anions

Polar and Helical Isomorphous Crystals of Proline Derivatives: Influence of a Fluorine Atom on the Electric Susceptibility

Contact Info

Product

Resources

About

Nonlinear Optical Crystals for Second Harmonic Generation

Cited by 9 publications

References 69 publications

Toward the Enhancement of Critical Performance for Deep-Ultraviolet Frequency-Doubling Crystals Utilizing Covalent Tetrahedra

Toward the Enhancement of Critical Performance for Deep-Ultraviolet Frequency-Doubling Crystals Utilizing Covalent Tetrahedra

Ba4Ag5(IO3)6(I3O8)3(I4O11)2: a nonlinear optical crystal containing two types of polyiodate anions

Polar and Helical Isomorphous Crystals of Proline Derivatives: Influence of a Fluorine Atom on the Electric Susceptibility

Contact Info

Product

Resources

About

Ba₄Ag₅(IO₃)₆(I₃O₈)₃(I₄O₁₁)₂: a nonlinear optical crystal containing two types of polyiodate anions