RESUMO
An electrically controlled ultra-compact surface plasmon polariton absorption modulator (SPPAM) is proposed. The device can be as small as a few micrometers depending on the required extinction ratio and the acceptable loss. The device allows for operation far beyond 100 Gbit/s, being only limited by RC time constants. The absorption modulator comprises a stack of metal/insulator/metal-oxide/metal layers, which support a strongly confined asymmetric surface plasmon polariton (SPP) in the 1.55 µm telecommunication wavelength window. Absorption modulation is achieved by electrically modulating the free carrier density in the intermediate metal-oxide layer. The concept is supported by proof-of-principle experiments.
Assuntos
Eletrônica/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Ressonância de Plasmônio de Superfície/instrumentação , Telecomunicações/instrumentação , Desenho de Equipamento , Análise de Falha de EquipamentoRESUMO
A laser setup to study shear oscillations at small amplitudes with resonance frequencies up to 3 MHz is presented. The new approach combines gauging of the Gaussian laser beam and a lock-in amplifier. The device is tested with a 3 MHz AT-cut quartz crystal. The oscillation amplitude at the edge of the electrode on the quartz crystal is measured with a resolution of 2 pm.
RESUMO
Single pulse laser interference lithography is used to structure self-assembled monolayers of thiols on gold. This structuring process is investigated by attenuated total reflection measurements, and a demixing process of a binary polymer blend is used to visualize the produced surface energy pattern. The lithography can be realized with different wavelengths (266, 532, and 1064 nm) which shows that the structuring is a thermal process. As a first demonstration of this process, structures down to 800 nm period and 300 nm width are fabricated.
Assuntos
Ouro/química , Difusão , Desenho de Equipamento , Lasers , Teste de Materiais , Microscopia de Força Atômica , Modelos Estatísticos , Conformação Molecular , Distribuição Normal , Fotoquímica/métodos , Polímeros/química , Compostos de Sulfidrila/química , Propriedades de Superfície , Temperatura , TermodinâmicaRESUMO
Optical surfaces coated with a thin layer to improve light transmission are ubiquitous in everyday optical applications as well as in industrial and scientific instruments. Discovered first in 1817 by Fraunhofer, the coating of lenses became standard practice in the 1930s. In spite of intensive research, broad-band antireflection coatings are still limited by the lack of materials with low refractive indices. A method based on the phase separation of a macromolecular liquid to generate nanoporous polymer films is demonstrated that creates surfaces with high optical transmission.