Polymer long-period raised rib waveguide gratings using nano-imprint lithography

This letter presents the fabrication and demonstration of a long-period raised rib waveguide grating using nano-imprint lithography. The device consists of a lower UV15 cladding, where relief-gratings are implemented, and an NOA73 raised rib core waveguide. Spectral transmission reveals a resonance at 1585 nm with about 10-dB rejection and 12-nm linewidth

Photolithographic and replication techniques for nanofabrication and photonics

In the pursuit of economical and rapid fabrication solutions on the micro and nano scale, polymer replication has proven itself to be a formidable technique, which despite zealous development by the research community, remains full of promise. This thesis explores the potential of elastomers in what is a distinctly multidisciplinary field. The focus is on developing innovative fabrication solutions for planar photonic devices and for nanoscale devices in general. Innovations are derived from treatments of master structures, imprintable substrates and device applications. Major contributions made by this work include fully replicated planar integrated optical devices, nanoscale applications for photolithographic standing wave corrugations (SWC), and a biologically templated, optical fiber based, surface-enhanced Raman scattering (SERS) sensor. The planar devices take the form of dielectric rib waveguides which for the first time, have been integrated with long-period gratings by replication. The heretofore unemployed SWC is used to demonstrate two innovations. The first is a novel demonstration of elastomeric sidewall photolithographic mask, which exploits the capacity of elastomers to cast undercut structures. The second demonstrates that the corrugations themselves in the absence of elastomers, can be employed as shadow masks in a directional flux to produce vertical stacks of straight lines and circles of nanowires and nanoribbons. The thesis then closes by conceptually combining the preceding demonstrations of waveguides and nanostructures. An optical fiber endface is em ployed for the first time as a substrate for patterning by replication, wherein the pattern is a nanostructure derived from a biological template. This replicated nanostructure is used to impart a SERS capability to the optical fiber, demonstrating an ultra-sensitive, integrated photonic device realized at great economy of both time and money, with very real potential for mass fabrication

Microengineered structures for rapid automatic loading of optical fibre segments

We present a technique to rapidly and automatically produce sections of optical fibre and load them into arrays such that they can be nano-imprinted in parallel. The technique makes use of automated fibre feeding, cutting and alignment with microfabricated groove arrays. The system is analyzed and optimized and it is found that the geometry of the arrays themselves is a critical factor. Three types of array are investigated-simple grooves, grooves with lateral funnels at the input, and bulk silicon machined V-groove arrays with funnels in both lateral and vertical dimensions. It is found that the incorporation of funnels significantly increases the accuracy of loading, overcoming the need for precise alignment, such that a throughput nearing 1000 fibre segments an hour can be achieved. This system forms part of a sequence of novel processes for the production of nano-photonic sensors

Nanocolumnar Preferentially Oriented PSZT Thin Films Deposited on Thermally Grown Silicon Dioxide

We report the first instance of deposition of preferentially oriented, nanocrystalline, and nanocolumnar strontium-doped lead zirconate titanate (PSZT) ferroelectric thin films directly on thermal silicon dioxide. No intermediate seed or activation layers were used between PSZT and silicon dioxide. The deposited thin films have been characterised using a combination of diffraction and microscopy techniques

Coagulopathy as initial manifestation of concomitant celiac disease and cystic fibrosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Celiac disease and cystic fibrosis have many common manifestations, such as malabsorption, steatorrhea and growth failure, and were for many years recognized as one clinical entity. Since their recognition as two separate diseases, their co-existence in a patient has been described sporadically; around 20 cases have been described in the literature. Taking into consideration the incidences of the two diseases, the chance of them occurring together is one in 2,000,000 in the general population.</p> <p>Case presentation</p> <p>We describe the case of a five-year-old boy of Turkish ethnicity with both celiac disease and cystic fibrosis, who presented initially with a skin hemorrhage. The diagnosis of celiac disease was made with a positive serum anti-tissue transglutaminase antibody test and the presence of HLA-DQ2 heterodimer, and confirmed on histology with small intestinal villous atrophy. A positive sweat test confirmed the diagnosis of associated cystic fibrosis.</p> <p>To the best of our knowledge there has been no previous report of this rare presentation of associated celiac disease and cystic fibrosis.</p> <p>Conclusion</p> <p>The clinical significance of this case is the consideration of malabsorption with both celiac disease and cystic fibrosis in patients who present with unexplained coagulopathy.</p

Replication of 3-D micro-structures on optical fibre facets using soft-imprint lithography

We demonstrate the realisation and operation of optical gratings and micro-prisms integrated onto the tips of optical fibres using soft-imprint lithography

The optical fiber tip: An inherently light-coupled microscopic platform for micro- and nanotechnologies

The flat tip of an optical fiber is a unique and unconventional platform for micro and nanotechnologies. The small cross-section and large aspect ratio of the fiber provide an inherently light-coupled substrate that is uniquely suited to remote, in vivo and in situ applications. However, these same characteristics challenge established fabrication technologies, which are best suited to large planar substrates. This review presents a broad overview of strategies for patterning the flat tip of an optical fiber. Techniques discussed include self-assembly, numerous lithographies, through-fiber patterning, hybrid techniques, and strategies for mass manufacture, while the diverse applications are discussed in context throughout

Soft imprinting of microstructured micro-prisms on optical fibre facets

Soft-imprint lithography is used to integrate optical gratings and polymer micro-prisms onto the tips of optical fibres. Light deflection and diffraction is demonstrated

Observation of random lasing action in dye doped polymer incorporating semi-ordered biological nanostructures from the wings of cicadas

We present a study of random lasing action from dye doped polymer with the scattering role of cicada wing nanostructures. Multimode peaks at 605nm with a mode linewidth of 0.55nm emission spectra were observed