Femtosecond laser direct writing is employed for the fabrication of buried tubular waveguides in bulk poly(methyl methacrylate). A novel technique using selective chemical etching is presented to resolve the two-dimensional refractive-index profile of the fabrication structures. End-to-end coupling in the waveguides reveals a near-field intensity distribution that results from the superimpositi...

The change in absorptivity during the degradation process of materials is discussed, and its influence as one of the involved parameters in the degradation models is studied. Three materials with very different behaviors are used for the demonstration of its role: a carbon composite material, which is opaque, almost grey, a plywood slab, which is opaque and spectral-dependent and a clear PMMA s...

Citation Do, Hyung Wan, Jae-Byum Chang, and Karl K. Berggren. “Three-Dimensional Nanofabrication Using Hydrogen Silsesquioxane/poly(methylmethacrylate) Bilayer Resists.” Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena 32, no. 6 (November 2014): 06F501. As Published http://dx.doi.org/10.1116/1.4893659 Publisher Amer...

Layers of poly(methyl methacrylate) doped with the Eu complex Eu(DPEPO)(hfac)3 (EuDH) provide a means for down-shifting incident ultraviolet (UV) light into the visible range, with beneficial effects on the performance of solar cells, as demonstrated with thin-film InGaP devices formed by epitaxial liftoff. Experimental and computational results establish important aspects of gain and loss mech...

An air-stable LiBH4 polymeric composite was successfully prepared by modifying LiBH4 with a gas-barrier polymer matrix, poly-(methylmethacrylate) (PMMA). The as-prepared LiBH4@PMMA composite started to dehydrogenate at 53 °C with the first main dehydrogenation peak at 116 °C, and 5.2 wt% of hydrogen released at 162 °C within 1 h.

One of the most significant issues that occurs when applying chemical-vapor deposited (CVD) graphene (Gr) to various high-performance device applications is the result of polymeric residues. Polymeric residues remain on the Gr surface during Gr polymer support transfer to an arbitrary substrate, and these residues degrade CVD Gr electrical properties. In this paper, we propose that a thin layer...

We present the design and fabrication of a phenanthrenequinone-doped poly(methyl methacrylate) photopolymer material. Large blocks of samples were made, and the material showed negligible shrinkage after optical exposures. We recorded and reconstructed 250 holograms at a single spot, using a 1-cm(3) block.

When the adhesive toe pads of geckos become wet, they become ineffective in enabling geckos to stick to substrates. This result is puzzling given that many species of gecko are endemic to tropical environments where water covered surfaces are ubiquitous. We hypothesized that geckos can recover adhesive capabilities following exposure of their toe pads to water by walking on a dry surface, simil...

Holographic gratings formed in thick phenanthrenquinone- (PQ-) doped poly(methyl methacrylate) (PMMA) can be made to have narrowband spectral and spatial transmittance filtering properties. We present the design and performance of angle-multiplexed holographic filters formed in PQ-PMMA at 488 nm and reconstructed with a LED operated at approximately 630 nm. The dark delay time between exposure ...

The effect of excitation and emission wavelengths on fluorescence decay times of Chlorophyll a were measured in four solutions (C approximately 10(-5) mol X 1(-1] and in polymethyl methacrylate films. The decay times observed were corrected with respect to self-absorption and re-emission effects. The fluorescence decay times of Chlorophyll a was found to depend on both the excitation and the em...