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Integrated super-couplers based on zero-index metamaterials

Conference Paper

Zero-refractive-index metamaterials have been proposed as potential candidates for super-coupling applications, where light is confined to sub- diffraction limited length scales on-chip. Such a device allows for efficient coupling between disparate modes...

Instrução pelos colegas e ensino sob medida: uma proposta para o engajamento dos alunos no processo de ensino-aprendizagem de Física (Peer Instruction and Just-in-Time Teaching: engaging students in physics learning)

Journal Article

Melhorar a formação profissional e acadêmica dos indivíduos nos mais diversos níveis, passa por repensar o papel das estratégias formais de ensino. Em termos educacionais, pesquisa após pesquisa tem mostrado os problemas de se investir quase...

The role of focusing in the interaction of femtosecond laser pulses with transparent materials

Thesis

Femtosecond lasers can generate extremely intense optical pulses, where the electric field is comparable to or greater than the field that binds electrons to their parent ions. In this regime, the interaction of light with transparent materials can become...

Femtosecond laser-induced microexplosions in transparent materials

Conference Paper

By focusing femtosecond laser pulses with high numerical-aperture microscope objectives, we micromachine optical glass using energies that are in the range of modern laser oscillators. When a femtosecond laser pulse is tightly focused inside a transparent...

Numerical aperture dependence of damage and supercontinuum generation from femtosecond laser pulses in bulk fused silica

Journal Article

Competing nonlinear optical effects are involved in the interaction of femtosecond laser pulses with transparent dielectrics: supercontinuum generation and multiphoton-induced bulk damage. We measured the threshold energy for supercontinuum generation and...

Laser induced microexplosions and applications in laser micromachining

Conference Paper

After reviewing some of the fundamentals of surface and bulk damage in transparent materials, we will present an overview of work being done in out laboratory on tighly focusing femtosecond pulses into the bulk of transparent materials with an emphasis on...

Numerical aperture dependence of damage and white light generation from femtosecond laser pulses in bulk fused silica

Conference Paper

The femtosecond laser has become an important tool in the micromachining of transparent materials. In particular, focusing at high numerical aperture enables structuring the bulk of materials. At low numerical aperture and comparable energy, focused...

Superhydrophobic surfaces prepared by microstructuring of silicon using a femtosecond laser

Journal Article

Superhydrophobic surfaces exhibit contact angles with water that are larger than 150 and negligible difference in contact angle between the advancing and receding contact angles, the so-called contact angle hysteresis. In this paper, we present a novel...

Morphology of femtosecond-laser-ablated borosilicate glass surfaces

Journal Article

We study the morphology of borosilicate glass surface machined by femtosecond laser pulses. Our observations show that a thin rim is formed around ablated craters after a single laser pulse. When multiple laser pulses are overlapped, the crater rims also...

Thermal and fluid processes of a thin melt zone during femtosecond laser ablation of glass

Conference Paper

Microfluidic channels on borosilicate glass are machined using femtosecond lasers. The morphology of the ablated surface is studied using scanning microscopy. The results show micron scale features inside the channels. The formation mechanism of these...

Submicrometer-wide amorphous and polycrystalline anatase TiO2 waveguides for microphotonic devices

Journal Article

We demonstrate amorphous and polycrystalline anatase TiO2 thin films and submicrometer-wide waveguides with promising optical properties for microphotonic devices. We deposit both amorphous and polycrystalline anatase TiO2 using reactive sputtering and...

Nucleation and Transport Organize Microtubules in Metaphase Spindles

Journal Article

Spindles are arrays of microtubules that segregate chromosomes during cell division. It has been difficult to validate models of spindle assembly due to a lack of information on the organization of microtubules in these structures. Here we present a...