プラズモンのメタ表面からの巨大な非線形応答は,サブバンド間の移行と結合しています
Jongwon Lee1, Mykhailo Tymchenko1, Christos Argyropoulos1
1Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, USA.
Nature
|July 4, 2014
まとめ
研究者らは,電磁気モードと半導体ヘテロ構造を組み合わせて,新しいプラズモンのメタ表面を開発しました. このブレークスルーにより,高度な光学デバイスの非線形光学応答が記録的に高くなる.
科学分野:
- 凝縮物質物理学 凝縮物質物理学
- 非線形光学は,非線形光学である.
- プラズモニクスはプラズモニクスを使います.
- 半導体ヘテロ構造は,半導体ヘテロ構造である.
背景:
- 半導体ヘテロ構造におけるサブバンド間移行は,大きな非線形光学応答を提供するが,特定の光極化に限定される.
- プラズモンのメタ表面は,光物質の相互作用を強化し,ユニークな波長特性を有する超薄なデバイスを可能にします.
研究 の 目的:
- 非線形光学応答を大幅に強化したメタ表面を提案し,実験的に実現する.
- プラズモンのメタ表面と量子エンジニアリングによる電子のサブバンド間の移行の間のカップリングを活用する.
- 汎用的な光学機能のための非線形感受性テンソーを設計する.
主な方法:
- プラズモニックと半導体ヘテロ構造のコンポーネントを組み合わせた超薄 (400nm) メタ表面の製造.
- 強化された非線形光学特性の実験的検証,特に第2ハーモニックジェネレーション (SHG).
- 約8マイクロメートルの波長で通常の発生下における非線形感受性テンソーの特徴.
主要な成果:
- SHGに対する非線形感受性は5 × 10^4 pm/Vを超え,これまでの光学メタ表面よりも数桁高い記録的な高さを達成しました.
- 非線形感受性テンソールの様々な要素を設計する能力を実証した.
- 効率的な周波数混合とブロードバンド周波数変換,相相結合,全光学制御の可能性が確認されています.
結論:
- 提案されているメタ表面は,超薄で高効率の光学要素を提供する非線形光学における重要な進歩を表しています.
- この技術により,周波数変換と全光信号処理における実用的な応用が可能になり,相対照要求が緩和される.
- エンジニアリングコップリングは,平面デバイスの非線形光学応答に対する前例のない制御を提供します.
関連する概念動画
01:24Superconductor
1.9K
A substance that reaches superconductivity, a state in which magnetic fields cannot penetrate, and there is no electrical resistance, is referred to as a superconductor. In 1911, Heike Kamerlingh Onnes of Leiden University, a Dutch physicist, observed a relation between the temperature and the resistance of the element mercury. The mercury sample was then cooled in liquid helium to study the linear dependence of resistance on temperature. It was observed that, as the temperature decreased, the...
1.9K
01:28Standing Waves in a Cavity
1.7K
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
1.7K
01:18Fermi Level
2.6K
The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
2.6K
01:12Fermi Level Dynamics
1.1K
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
1.1K
01:01Energy Bands in Solids
2.4K
Isolated atoms have discrete energy levels that are well described by the Bohr model. And, it quantifies the energy of an electron in a hydrogen atom as En. Higher quantum numbers 'n' yield less negative, closer electron energy levels.
Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states...
Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states...
2.4K
01:24Metal-Semiconductor Junctions
1.4K
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
1.4K