scholarly journals Giant Nonlinear Optical Activity in Two-Dimensional Palladium Diselenide

2020 ◽  
Author(s):  
Juan YU ◽  
Xiaofei KUANG ◽  
Junzi Li ◽  
Jiahong Zhong ◽  
Cheng Zeng ◽  
...  

Abstract Nonlinear optical (NLO) effects in layered atomically thin two-dimensional (2D) materials provide a promising prospect for multifarious optoelectronic applications. The NLO characteristics of transition metal chalcogenides (TMDCs) are attracting growing attention and have been extensively explored recently. However, these materials possess sizable bandgaps ranging from visible to ultraviolet regions, so the investigation of narrow-bandgap materials remains deficient. Here, we report our comprehensive study on the NLO processes in palladium diselenide (PdSe2) flakes that have a near-infrared bandgap. Interestingly, this material exhibits a unique thickness-dependent second harmonic generation (SHG) feature, embodied in the strong (negligible) SHG signals in even (odd) layers, in contrast with that of other TMDCs. Furthermore, the two-photon absorption (TPA) coefficients (β ~4.5×105, 2.83×105, 1.7×105, and 1.85×104 cm/GW) of 1-3 L and bulk PdSe2 are larger by two and three orders of magnitude, compared with that of the conventional 2D materials. Significantly, at the excitation wavelength of 600 nm, a robust saturable absorption with giant modulation depths (αs ~47%, 30%, and 41%) was observed in 1-3 L PdSe2, which has yet been obtained in other 2D materials. Such unique NLO characteristics enable PdSe2 to be a potential candidate for technological innovations in nonlinear optoelectronic devices.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Juan Yu ◽  
Xiaofei Kuang ◽  
Junzi Li ◽  
Jiahong Zhong ◽  
Cheng Zeng ◽  
...  

AbstractNonlinear optical effects in layered two-dimensional transition metal chalcogenides have been extensively explored recently because of the promising prospect of the nonlinear optical effects for various optoelectronic applications. However, these materials possess sizable bandgaps ranging from visible to ultraviolet region, so the investigation of narrow-bandgap materials remains deficient. Here, we report our comprehensive study on the nonlinear optical processes in palladium diselenide (PdSe2) that has a near-infrared bandgap. Interestingly, this material exhibits a unique thickness-dependent second harmonic generation feature, which is in contrast to other transition metal chalcogenides. Furthermore, the two-photon absorption coefficients of 1–3 layer PdSe2 (β ~ 4.16 × 105, 2.58 × 105, and 1.51 × 105 cm GW−1) are larger by two and three orders of magnitude than that of the conventional two-dimensional materials, and giant modulation depths (αs ~ 32%, 27%, and 24%) were obtained in 1–3 layer PdSe2. Such unique nonlinear optical characteristics make PdSe2 a potential candidate for technological innovations in nonlinear optoelectronic devices.


Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1787-1810 ◽  
Author(s):  
Xiao Han ◽  
Yongshen Zheng ◽  
Siqian Chai ◽  
Songhua Chen ◽  
Jialiang Xu

AbstractTwo-dimensional (2D) organic-inorganic hybrid perovskites feature characteristics of inherent quantum-well structures and intriguing optoelectronic properties, and have therefore attracted enormous research attention for their optical applications in light emitting, sensing, modulation, and telecommunication devices. The low-cost and solution-processed fabrications as well as alternative organic spacer cations endue 2D hybrid perovskites with higher tunability in optical and photonic applications. In particular, they demonstrate distinguished nonlinear optical characters such as second-harmonic generation (SHG), two-photon absorption (2PA), and saturable absorption (SA) under the excitation of laser pulses. Here, we discuss the construction of the various sorts of 2D hybrid perovskites with different structural features. We have also highlighted some representative properties and applications of these 2D hybrid perovskites in both linear and nonlinear optical regimes.


2006 ◽  
Vol 15 (04) ◽  
pp. 481-490
Author(s):  
SHENG-LI GUO ◽  
ZHUN GUO ◽  
T. SUSDORF ◽  
TIAN-DE CAO

An optical spectroscopic characterization is carried out on a reactive dye (reactive orange 1). This dye is widely applied in textile coloration. It is a potential candidate for photonics applications. Its absorption cross-section spectra are measured. A fluorescence spectroscopic characterization is undertaken by measuring the fluorescence quantum distributions and fluorescence quantum yields. The saturable absorption is studied by nonlinear transmission measurements with intense picosecond laser pulses (second harmonic pulses of a mode-locked Nd :glass laser). The nonlinear optical absorption and refraction coefficients are measured by using the top-hat Z-scan technique at a wavelength of 532 nm with 35 ps duration pulses. Reactive orange 1 has the two-photon absorption coefficient of 1.20 cm/GW and the nonlinear refraction coefficient of -7.33 × 10-6 cm2/GW, respectively. In reactive orange 1, there occurs fast ground-state recovery by internal conversion likely via conical intersections. Low excited-state absorption and fast ground-state absorption recovery make it an ideal candidate for passive mode-locking of picosecond and femtosecond lasers as well as for fast nonlinear optical gating.


Nanophotonics ◽  
2018 ◽  
Vol 7 (5) ◽  
pp. 873-881 ◽  
Author(s):  
Rui Li ◽  
Yajun Zhang ◽  
Xuefeng Xu ◽  
Yi Zhou ◽  
Maodu Chen ◽  
...  

AbstractIn this paper, we employ the nonlinear optical microscopies of coherent anti-Stokes Raman scattering spectroscopy, two-photon excitation fluorescence, and second harmonic generation to characterize the properties of two-dimensional (2D) materials. With these nonlinear optical microscopy methods, we can not only clearly observe the surface topography of 2D materials but also reveal the quality of 2D materials. These nonlinear optical microscopies offer great potential for characterization of the properties of 2D materials.


Nanophotonics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1341-1358
Author(s):  
Jialin Ma ◽  
Mengtao Sun

AbstractIn this review, we focus on the summary of nonlinear optical microscopies (NOMs), which are stimulated Raman scattering (SRS), coherent anti-Stokes Raman scattering (CARS), second harmonic generation (SHG), and two-photon excited fluorescence (TPEF). The introduction is divided into two parts: the principle of SRS, CARS, TPEF, and SHG and their application to biology and two-dimensional materials. We also introduce the connections and differences between them. We also discuss the principle of plasmon-enhanced NOM and its application in the above two aspects. This paper not only summarizes the research progress in the frontier but also deepens the readers’ understanding of the physical principles of these NOMs.


Author(s):  
Mao-Yin Ran ◽  
Zuju Ma ◽  
Xintao Wu ◽  
Hua Lin ◽  
Qi-Long Zhu

The class of non-centrosymmetric (NCS) metal chalcogenides is the most favorable candidates for promising nonlinear optical (NLO) crystals in the infrared (IR) band. However, most research achievements pay them attention...


2021 ◽  
Author(s):  
WEN-SHUO KUO ◽  
Chia-Yuan Chang ◽  
Ping-Ching Wu ◽  
Jiu-Yao Wang

Abstract BackgroundNitrogen doping and amino-group functionalization, which result in strong electron donation, can be achieved through chemical modification. Large π-conjugated systems of graphene quantum dot (GQD)-based materials acting as electron donors can be chemically manipulated with low two-photon excitation energy in a short photoexcitation time for improving the charge transfer efficiency of sorted nitrogen-doped amino acid–functionalized GQDs (sorted amino-N-GQDs). ResultsIn this study, a self-developed femtosecond Ti-sapphire laser optical system (222.7 nJ pixel−1 with 100-170 scans, approximately 0.65-1.11 s of total effective exposure times; excitation wavelength: 960 nm in the near-infrared II region) was used for chemical modification. The sorted amino-N-GQDs exhibited enhanced two-photon absorption, post-two-photon excitation stability, two-photon excitation cross-section, and two-photon luminescence through the radiative pathway. The lifetime and quantum yield of the sorted amino-N-GQDs decreased and increased, respectively. Furthermore, the sorted amino-N-GQDs exhibited excitation-wavelength-independent photoluminescence in the near-infrared region and generated reactive oxygen species after two-photon excitation. An increase in the size of the sorted amino-N-GQDs boosted photochemical and electrochemical efficacy and resulted in high photoluminescence quantum yield and highly efficient two-photon photodynamic therapy. ConclusionThe sorted dots can be used in two-photon contrast probes for tracking and localizing analytes during two-photon imaging in a biological environment and for conducting two-photon photodynamic therapy for eliminating infectious microbes.


Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2407-2414 ◽  
Author(s):  
Yuan Liu ◽  
Gongxun Bai ◽  
Li Jiang ◽  
Youjie Hua ◽  
Liang Chen ◽  
...  

AbstractUltrathin two-dimensional (2D) materials have drawn great attention in recent years due to their promising applications in biomedicine and atomically optoelectronic devices. In this work, we have fabricated a 2D In2Se3 nanosheet doped with Nd3+ ions via the two-step method of solid phase synthesis and liquid exfoliation. Owing to the special inner 4f-4f energy level transitions, lanthanide ions can emit photons with almost the same energy in different environments. Here, a stable near-infrared luminescence from Nd3+-doped 2D In2Se3 nanosheets has been realized, which includes emission bands around 910, 1057, and 1324 nm. The doping of Nd3+ ions extends the emission region of In2Se3 nanosheets. Moreover, the photoluminescence mechanism of Nd3+ ions was investigated through a series of optical measurements. This work not only provides a reliable method to fabricate lanthanide ion-doped 2D materials but also possesses a great significance for luminescence study of lanthanide ions in the 2D matrix.


2014 ◽  
Vol 07 (02) ◽  
pp. 1450011 ◽  
Author(s):  
Bei Zhang ◽  
Yu-Mei Zhao ◽  
Guo-Ping Yong

A new enantiomerically pure compound was synthesized by the single step reduced reaction from 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxo- N -(pyridin-2-yl)acetamide via chiral induction with D-tartaric acid in good yield. Single crystal data confirm this compound crystallizes in chiral space group P21. Transmission spectrum reveals that the crystal has low UV cut-off of 372 nm and has a good transmittance in the entire visible and near-infrared (NIR)region to 1100 nm, indicating its optical application. Kurtz powder test shows a good second harmonic generation (SHG) which also demonstrates its chiral structure. Moreover, this material exhibits blue phosphorescence with quantum yield of 3.6% and unusually NIR absorption between 1500 nm and 2500 nm. Therefore, this new chiral crystal is a promising multifunctional material for the blue phosphorescence, NIR absorption and nonlinear optical (NLO) applications.


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