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Intersubband Polaritonics in Dielectric Metasurfaces

Sarma, Raktim S.; Sarma, Raktim S.; Nookala, Nishant N.; Nookala, Nishant N.; Kevin, Reilly K.; Kevin, Reilly K.; Liu, Sheng L.; Liu, Sheng L.; Domenico, de C.; Domenico, de C.; Goldflam, Michael G.; Goldflam, Michael G.; Luca, Carletti L.; Luca, Carletti L.; Campione, Salvatore; Campione, Salvatore; Klem, John F.; Klem, John F.; Sinclair, Michael B.; Sinclair, Michael B.; Belkin, Mikhail B.; Belkin, Mikhail B.; Brener, Igal B.; Brener, Igal B.

Abstract not provided.

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TYPE Conference Poster YEAR 2019
OSTI

Low-Power Absorption Saturation in Semiconductor Metasurfaces

ACS Photonics

Zubyuk, Varvara V.; Vabishchevich, Polina V.; Shcherbakov, Maxim R.; Shorokhov, Alexander S.; Fedotova, Anna N.; Liu, Sheng; Keeler, Gordon; Dolgova, Tatyana V.; Staude, Isabelle; Brener, Igal B.; Fedyanin, Andrey A.

Saturable optical elements lie at the cornerstone of many modern optical systems. Regularly patterned quasi-planar nanostructures - metasurfaces - are known to facilitate nonlinear optical processes. Such subwavelength semiconductor nanostructures can potentially serve as saturable components. Here we report on the intensity-dependent reflectance of femtosecond laser pulses from semiconductor metasurfaces with Mie-type modes, caused by the absorption saturation. Arrays of GaAs nanocylinders with magnetic dipole resonances in the spectral vicinity of the GaAs bandgap demonstrate a reduced saturation intensity and increased self-modulation efficiency, an order of magnitude higher than bulk GaAs or unstructured GaAs films. By contrast, the reflection modulation is shown to be negligible in the CW regime for the same average intensities, indicating that the process is not the result of temperature effects. Our work provides a novel idea for low-power saturable elements based on nonthermal nature of saturation. We conclude by devising a high-quality metasurface that can be used, in theory, to further reduce the saturation fluence below 50 nJ/cm2.

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TYPE Journal Article YEAR 2019
ScopusOSTIDOI

High-harmonic generation from an epsilon-near-zero material

Nature Physics

Yang, Yuanmu; Lu, Jian; Manjavacas, Alejandro; Luk, Ting S.; Liu, Hanzhe; Kelley, Kyle; Maria, Jon P.; Runnerstrom, Evan L.; Sinclair, Michael B.; Ghimire, Shambhu; Brener, Igal B.

High-harmonic generation (HHG) is a signature optical phenomenon of strongly driven, nonlinear optical systems. Specifically, the understanding of the HHG process in rare gases has played a key role in the development of attosecond science1. Recently, HHG has also been reported in solids, providing novel opportunities such as controlling strong-field and attosecond processes in dense optical media down to the nanoscale2. Here, we report HHG from a low-loss, indium-doped cadmium oxide thin film by leveraging the epsilon-near-zero (ENZ) effect3–8, whereby the real part of the material’s permittivity in certain spectral ranges vanishes, as well as the associated large resonant enhancement of the driving laser field. We find that ENZ-assisted harmonics exhibit a pronounced spectral redshift as well as linewidth broadening, resulting from the photo induced electron heating and the consequent time-dependent ENZ wavelength of the material. Our results provide a new platform to study strong-field and ultrafast electron dynamics in ENZ materials, reveal new degrees of freedom for spectral and temporal control of HHG, and open up the possibilities of compact solid-state attosecond light sources.

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TYPE Journal Article YEAR 2019
ScopusOSTIDOI

All-optical tuning of symmetry protected quasi bound states in the continuum

Applied Physics Letters

Karl, Nicholas J.; Vabishchevich, Polina V.; Liu, Sheng; Sinclair, Michael B.; Keeler, Gordon A.; Peake, Gregory M.; Brener, Igal B.

We demonstrate all-optical switching of high quality factor quasibound states in the continuum resonances in broken symmetry GaAs metasurfaces. By slightly breaking the symmetry of the GaAs nanoresonators, we enable leakage of symmetry protected bound states in the continuum (BICs) to free space that results in sharp spectral resonances with high quality factors of ∼500. We tune the resulting quasi-BIC resonances with ultrafast optical pumping at 800 nm and observe a 10 nm spectral blue shift of the resonance with pump fluences of less than 100 μJ cm-2. The spectral shift is achieved in an ultrafast time scale (<2.5 ps) and is caused by a shift in the refractive index mediated by the injection of free carriers into the GaAs resonators. An absolute reflectance change of 0.31 is measured with 150 μJ cm-2. Our results demonstrate a proof-of-concept that these broken symmetry metasurfaces can be modulated or switched at ultrafast switching speeds with higher contrast at low optical fluences (<100 μJ cm-2) than conventional Mie-metasurfaces.

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TYPE Journal Article YEAR 2019
ScopusOSTIDOI

All-Dielectric Metasurfaces: Optical Nonlinearities and Emission Control

2019 IEEE Photonics Conference, IPC 2019 - Proceedings

Vabishchevich, Polina V.; Sharma, Andrei; Sinclair, Michael B.; Brener, Igal B.; Peake, Gregory M.; Karl, Nicholas J.; Balakrishnan, Ganesh; Staude, Isabelle; Vaskin, Aleksandr; Liu, Sheng; Reno, J.L.; Keeler, Gordon A.; Addamane, Sadhvikas J.

In this work we show our results on the harmonic generation and nonlinear frequency mixing enhanced by Mie modes in GaAs metasurfaces. Moreover, we show enhancement and directionality control of the quantum dot emission embedded in the metasurface.

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TYPE Conference Poster YEAR 2019
ScopusOSTIDOI
Results 26–50 of 419
Results 26–50 of 419