High-contrast optical switching using an epsilon-near-zero material coupled to a Bragg microcavity

Hu, Futai; Jia, Wenhe; Meng, Yuan; Gong, Mali; Yang, Yuanmu

doi:10.1364/oe.27.026405

Cited by 16 publications

(10 citation statements)

References 41 publications

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“…The plasma frequency ω p can be written as 27 : where m = 0.12 m 0 ( m 0 the free electron mass) denotes the effective mass, ħ is the reduced Plank’s constant, C = 0.34 eV −1 19 determines the structure of non-parabolic conduction, and the function f 0 ( E , T e ) is the Fermi–Dirac distribution function determined by electron temperature T e and the electron energy E . Here, electron-temperature-dependence of f 0 is mainly due to the fact that T e can produce a change in electro-chemical potential and thereby modifying Fermi–Dirac function.…”

Section: Methodsmentioning

confidence: 99%

“…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%

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

Sha

Xie

et al. 2022

Sci Rep

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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.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

Sha

Xie

et al. 2022

Sci Rep

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“…where ε 0 is the vacuum permittivity, c is the speed of light in vacuum, ω is the angular frequency of light, and χ ð3Þ is the material's third-order nonlinear susceptibility. The giant optical nonlinearity of ENZ materials has been exploited for secondand third-harmonic generation, [33][34][35] high-harmonic generation, 36 terahertz wave generation, 37,38 all-optical switching, [39][40][41][42] and temporal pulse shaping. [43][44][45][46] Moreover, it has been shown that the strong coupling between a plasmonic metasurface and a thin film made of an ENZ material can result in a further enhanced and tailorable nonlinear optical response.…”

Section: Introductionmentioning

confidence: 99%

Intracavity spatiotemporal metasurfaces

et al. 2023

Self Cite

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Optical metasurfaces are endowed with unparallel flexibility to manipulate the light field with a subwavelength spatial resolution. Coupling metasurfaces to materials with strong optical nonlinearity may allow ultrafast spatiotemporal light field modulation. However, most metasurfaces demonstrated thus far are linear devices. Here, we experimentally demonstrate simultaneous spatiotemporal laser mode control using a single-layer plasmonic metasurface strongly coupled to an epsilon-near-zero (ENZ) material within a fiber laser cavity. While the geometric phase of the metasurface is utilized to convert the laser's transverse mode from a Gaussian beam to a vortex beam carrying orbital angular momentum, the giant nonlinear saturable absorption of the ENZ material enables pulsed laser generation via the Q-switching process. The direct integration of a spatiotemporal metasurface in a laser cavity may pave the way for the development of miniaturized laser sources with tailored spatial and temporal profiles, which can be useful for numerous applications, such as superresolution imaging, high-density optical storage, and three-dimensional laser lithography.

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“…12−14 Among these, ENZ materials represented by transparent conductive oxides (TCOs) have a large nonlinear response, 15,16 sub-picosecond response time, 17 and good complementary metal oxide semiconductor (CMOS) compatibility, 18 making them a potential all-optical switching material platform. ENZ-enhanced nonlinear refraction has inspired many studies on ultrafast all-optical switches based on TCOs, such as unpatterned ENZ films, 12,13 ENZ microcavities, 14,19 nanorods, 20,21 and nanocrystals. 22,23 A representative study in this field is the development of an ultrafast polarization alloptical switch based on the CdO Berreman microcavity proposed by Yang et al, 14 which achieved an absolute modulation depth of 85.3% at a pump fluence of 339 μJ cm −2 at 2.08 μm.…”

mentioning

confidence: 99%

“…Numerous material platforms have been demonstrated for ultrafast all-optical switches, such as semiconductors, metamaterials, , two-dimensional (2D) materials, , perovskites, , and ENZ materials. − Among these, ENZ materials represented by transparent conductive oxides (TCOs) have a large nonlinear response, , sub-picosecond response time, and good complementary metal oxide semiconductor (CMOS) compatibility, making them a potential all-optical switching material platform. ENZ-enhanced nonlinear refraction has inspired many studies on ultrafast all-optical switches based on TCOs, such as unpatterned ENZ films, , ENZ microcavities, , nanorods, , and nanocrystals. , A representative study in this field is the development of an ultrafast polarization all-optical switch based on the CdO Berreman microcavity proposed by Yang et al, which achieved an absolute modulation depth of 85.3% at a pump fluence of 339 μJ cm –2 at 2.08 μm. However, similarly to photonic crystal or plasmonic crystal optical switches, − these optical switches operate on the principle of a nonlinear refraction-induced resonant mode shift, making it difficult to achieve wide-wavelength operation.…”

mentioning

confidence: 99%

Broad-Band Ultrafast All-Optical Switching Based on Enhanced Nonlinear Absorption in Corrugated Indium Tin Oxide Films

Jiang

Zhao

et al. 2022

ACS Nano

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Ultrafast all-optical switches based on epsilon-near-zero (ENZ)-enhanced nonlinear refraction in transparent conducting oxides have achieved exciting results in realizing large absolute modulations. However, broad-band, polarization-independent, and wide-angle ultrafast all-optical switches have been challenging to produce, due to the inherent narrow band, polarization-dependent, and angle-dependent characteristics of the ENZ effect. To this end, we propose an ultrafast all-optical switch based on the enhanced nonlinear absorption of corrugated indium tin oxide (ITO) thin films. Taking advantage of the perfect absorption and localized field enhancement of the ENZ and localized surface plasmon resonance modes, we significantly enhanced the nonlinear absorption of the corrugated ITO film in the 1450–1650 nm telecom band. The experimental results show that the nonlinear saturable absorption coefficient of the corrugated ITO film at 1450 nm was as high as −1.5 × 105 cm GW–1, enabling all-optical switching to obtain an extinction ratio of 14.32 dB and an ultrafast switching time of 350 fs at a pump fluence of 18.51 mJ cm–2. Furthermore, the all-optical switch achieved an extinction ratio of over 15 dB and an insertion loss of approximately 2.6 dB within the 200 nm absorption band and exhibited polarization-independent and wide-angle features. The ultrafast temporal response can be attributed to intraband transient bleaching of the corrugated ITO film. Our findings demonstrate that corrugated ENZ films can overcome the inherent narrow-band, polarization-dependent, and angle-dependent problems of natural ENZ materials without increasing the response time, making them a potential ENZ ultrafast all-optical switching material platform.

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High-contrast optical switching using an epsilon-near-zero material coupled to a Bragg microcavity

Cited by 16 publications

References 41 publications

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

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

Intracavity spatiotemporal metasurfaces

Broad-Band Ultrafast All-Optical Switching Based on Enhanced Nonlinear Absorption in Corrugated Indium Tin Oxide Films

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