We demonstrate a free-space amplitude modulator for mid-infrared radiation (λ ≈ 9.6 μm) that operates at room temperature up to at least 20 GHz (above the −3 dB cutoff frequency measured at 8.2 GHz). The device relies on the ultrafast transition between weak- and strong-coupling regimes induced by the variation of the applied bias voltage. Such transition induces a modulation of the device reflectivity. It is made of a semiconductor heterostructure enclosed in a judiciously designed array of metal-metal optical resonators, that—all-together—behave as an electrically tunable surface. At negative bias, it operates in the weak light-matter coupling regime. Upon application of an appropriate positive bias, the quantum wells populate with electrons, and the device transitions to the strong-coupling regime. The modulator transmission remains linear with input radio frequency power in the 0-9 dBm range. The increase in optical powers up to 25 mW exhibit a weak beginning of saturation a little bit below.

Ultrafast (≈10 GHz) mid-IR modulator based on ultrafast electrical switching of the light-matter coupling / Malerba, M.; Pirotta, S.; Aubin, G.; Lucia, L.; Jeannin, M.; Manceau, J. -M.; Bousseksou, A.; Lin, Q.; Lampin, J. -F.; Peytavit, E.; Barbieri, S.; Li, L. H.; Davies, A. G.; Linfield, E. H.; Colombelli, R.. - In: APPLIED PHYSICS LETTERS. - ISSN 0003-6951. - 125:4(2024). [10.1063/5.0213965]

Ultrafast (≈10 GHz) mid-IR modulator based on ultrafast electrical switching of the light-matter coupling

Malerba M.;
2024

Abstract

We demonstrate a free-space amplitude modulator for mid-infrared radiation (λ ≈ 9.6 μm) that operates at room temperature up to at least 20 GHz (above the −3 dB cutoff frequency measured at 8.2 GHz). The device relies on the ultrafast transition between weak- and strong-coupling regimes induced by the variation of the applied bias voltage. Such transition induces a modulation of the device reflectivity. It is made of a semiconductor heterostructure enclosed in a judiciously designed array of metal-metal optical resonators, that—all-together—behave as an electrically tunable surface. At negative bias, it operates in the weak light-matter coupling regime. Upon application of an appropriate positive bias, the quantum wells populate with electrons, and the device transitions to the strong-coupling regime. The modulator transmission remains linear with input radio frequency power in the 0-9 dBm range. The increase in optical powers up to 25 mW exhibit a weak beginning of saturation a little bit below.
2024
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11696/85700
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