Comparative study on epsilon-near-zero transparent conducting oxides: High-order chromatic dispersions and modeling of ultrashort pulse interactions

Wu, Jiaye; Xie, Ze Tao; Sha, Yanhua; Fu, H. Y.; Li, Qian

doi:10.1103/physreva.102.053503

Cited by 16 publications

(8 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 2, it is obvious that the real 𝑅𝑒(𝜀) of the permittivity of the ENZ wavelength (𝜆 = 1550 nm) vanishes and the imaginary 𝐼𝑚(𝜀) is 0. The parameters of the AZO film are derived from the literature [8], where ε ∞ = 3.8 is the high-frequency permittivity, γ = 9.71 × 10 15 rad•s −1 is the Drude damping rate, ω p = 2.3765 × 10 15 rad•s −1 is the plasma frequency, ω is the angular frequency of the incident light, n is the carrier concentration, e =1.602 × 10 −19 C is the electron charge, ε 0 is the permittivity of free space, µ is the electron mobility, m e = 0.38m is the effective electron mass [29] and m is the electron mass. As shown in Figure 2, it is obvious that the real Re(ε) of the permittivity of the ENZ wavelength (λ ENZ = 1550 nm) vanishes and the imaginary Im(ε) is 0.3.…”

Section: Methodsmentioning

confidence: 99%

“…ENZ materials exhibit a vanishing real part of permittivity in certain spectral ranges and strong localization of the field, which is a class of zero-refractive-index (NZI) materials [1][2][3][4][5] with a high nonlinear coefficient [6,7] and unprecedented ultrafast nonlinearity in the subwavelength propagation length. Al-doped zinc oxide (AZO) is an ideal ENZ material; it has a lower loss [8] and confines light better than indium tin oxide (ITO). However, the ENZ material only has a large nonlinear response in a relatively narrow spectral range and is sensitive to polarization, which limits its application.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Polarization-Independent Large Third-Order-Nonlinearity of Orthogonal Nanoantennas Coupled to an Epsilon-Near-Zero Material

2021

View full text Add to dashboard Cite

The nonlinear optical response of common materials is limited by bandwidth and energy consumption, which impedes practical application in all-optical signal processing, light detection, harmonic generation, etc. Additionally, the nonlinear performance is typically sensitive to polarization. To circumvent this constraint, we propose that orthogonal nanoantennas coupled to Al-doped zinc oxide (AZO) epsilon-near-zero (ENZ) material show a broadband (~1000 nm bandwidth) large optical nonlinearity simultaneously for two orthogonal polarization states. The absolute maximum value of the nonlinear refractive index n2 is 7.65 cm2∙GW−1, which is 4 orders of magnitude larger than that of the bare AZO film and 7 orders of magnitude larger than that of silica. The coupled structure not only realizes polarization independence and strong nonlinearity, but also allows the sign of the nonlinear response to be flexibly tailored. It provides a promising platform for the realization of ultracompact, low-power, and highly nonlinear all-optical devices on the nanoscale.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Polarization-Independent Large Third-Order-Nonlinearity of Orthogonal Nanoantennas Coupled to an Epsilon-Near-Zero Material

2021

View full text Add to dashboard Cite

show abstract

“…2(b). It can be found that the peak absorption appears at the wavelength that maximizes the ratio of |Im(ε ITO )|/|Re(ε ITO )| 2 , near the communication wavelength, and it may be caused by the plasmon resonance of ITO near the ENZ point [42]. With the increase of the number of layers, the thickness of each layer decreases, and the whole multilayer structure shows better absorption effect due to the enhanced light scattering and the enhanced light localization caused by the multimode resonance effect [43], [44].…”

Section: Absorption Mechanisms Of Enz Multilayersmentioning

confidence: 99%

Optimization of Epsilon-Near-Zero Multilayers for Near-Perfect Light Absorption Using an Enhanced Genetic Algorithm

Wang

et al. 2021

IEEE Photonics J.

Self Cite

View full text Add to dashboard Cite

Using epsilon-near-zero (ENZ) subwavelength optical multilayer materials with simple structure and thin total thickness to achieve target characteristics is extremely important and beneficial for the realization of on-chip integration and largescale application of optical devices. Combining with the enhanced genetic algorithm (EGA), this work breaks the limitation of the periodicity of traditional ENZ multilayer structures, and investigates the aperiodic ENZ transparent conducting oxide (TCO)-dielectric multilayer structures. It is realized that under the given conditions, an optimal structure can possess a maximum peak absorption and the broadest absorption bandwidth near the communication wavelength. In the 6-layer structure with a total thickness of 600 nm studied in this work, EGA can optimize the peak absorption from 0.91 to 0.95. Additionally, the absorption bandwidth is optimized from 120 nm to 227 nm, which is enhanced more than 180%. The absorption performance of this optimized structure is comparable to that of a more complex structure with the same total thickness but more layers, or a structure with the same number of layers but a larger total thickness. Conclusively, the proposed EGA optimization method can simplify the structure of the multilayer system, reduce the total thickness of the required ENZ material, and thus greatly simplify the production process and reduce the production cost.

show abstract

“…In the recent two decades, transparent conductive oxide (TCO) such as indium tin oxide (ITO) 11 , aluminum-doped zinc oxide (AZO) 12 , cadmium oxide (CdO) 13 have attracted considerable interest in epsilon-near-zero (ENZ) spectral region. Such media exhibit a vanishing permittivity at ENZ wavelength, giving rise to a series of new physical phenomena 14 , such as enhanced electric field 15 , large optical nonlinearity 11 , ultrashort pulse interaction 16 , etc., and advanced applications including electro-optical modulator 17 , 18 , all-optical switch 19 , perfect absorber 13 , etc. For all-optical switching, ENZ TCO materials also have several advantages, such as greater refractive index change by pump excitation, ultrafast response time 11 , and intraband optical excitation 13 .…”

Section: Introductionmentioning

confidence: 99%

All-optical switching in epsilon-near-zero asymmetric directional coupler

Sha

Xie

et al. 2022

Sci Rep

View full text Add to dashboard Cite

We propose an all-optical switch based on an asymmetric directional coupler structure with epsilon-near-zero (ENZ) layer. The nonlinear optical properties the of ENZ layer are analyzed by hot-electron dynamics process, and the all-optical operating performance of the switch on the silicon nitride platform is investigated. It is found that the pump-induced refractive index change in ENZ layer gives rise to a transfer of signal light in the optical system. We demonstrate that the proposed switch design features an insertion loss of < 2.7 dB, low crosstalk of < − 18.93 dB, and sub-pico-second response time at the communication wavelength of 1.55 μm. With ultrafast response, high performance, and simple structure, the device provides new possibilities for all-optical communication and signal processing.

show abstract

Comparative study on epsilon-near-zero transparent conducting oxides: High-order chromatic dispersions and modeling of ultrashort pulse interactions

Cited by 16 publications

References 44 publications

Polarization-Independent Large Third-Order-Nonlinearity of Orthogonal Nanoantennas Coupled to an Epsilon-Near-Zero Material

Polarization-Independent Large Third-Order-Nonlinearity of Orthogonal Nanoantennas Coupled to an Epsilon-Near-Zero Material

Optimization of Epsilon-Near-Zero Multilayers for Near-Perfect Light Absorption Using an Enhanced Genetic Algorithm

All-optical switching in epsilon-near-zero asymmetric directional coupler

Contact Info

Product

Resources

About