156 research outputs found
Experimental observation of whispering gallery modes in novel silicon microcylindrical resonators
No full textMicroresonators that support whispering gallery modes (WGMs) are ideal systems for studying nonlinear phenomena at low thresholds due to the small mode volumes and the high quality (Q) factors and, as such, they are currently generating much scientific interest [1]. A variety of geometries have been investigated including microspheres, microdisks, toroids and micropillars, using a range of dielectrics and, more recently, semiconductor materials. One of the major challenges in fabricating semiconductor microresonators is obtaining the smooth, defect-free, surfaces required for high Q operation. In this paper, we present a novel approach to fabricating high quality silicon microcylindrical resonators starting from the silicon optical fibre platform [2]. The silicon fibres are fabricated using a high pressure chemical deposition technique to fill silica capillaries with the semiconductor material. This process can be easily modified to fill capillaries of various internal diameters with the deposited material taking on the pristine smoothness of the capillary walls (0.1 nm RMS). As an optical material, silicon is particularly attractive due to its broad transparency window that extends from the telecoms band to the mid-IR (~1.2–7µm), as well as its high optical damage threshold and large nonlinearities
Infrared fibers
No full textAbstract not availableGuangming Tao, Heike Ebendorff-Heidepriem, Alexander M. Stolyarov, Sylvain Danto, John V. Badding, Yoel Fink, John Ballato, and Ayman F. Abouradd
Single-crystal semiconductor wires integrated into microstructured optical fibers
No full textAssembly and integration of photonic and electronic building blocks such as semiconductor micro/nanowires into more complex structures is critical to the realization of advanced materials and devices useful for a diverse range of applications
Building semiconductor structures in optical fiber
No full textFabrication of semiconductor devices inside microstructured optical fiber may lead to all-fiber optoelectronics. In addition, the pervasive nature of electronics and optoelectronics technology based on silicon, GaAs and other crystalline semiconductors is familiar to almost all scientists and engineers...
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Flexible semi-conductor devices in microstructured optical fibers for integrated optoelectronics
No full textHere we present a novel group of flexible semiconductor electronic/optoelectronic devices made in microstructured optical fibers with extreme aspect ratios. These devices are motivated by incorporating the optoelectronic capabilities of semiconductor structures into optical fibers, the backbone for the modern optical communications. The joint of these two key techniques could enable all-fiber networks, in which light generation, modulation, transmission, and detection can all be performed within a fiber. One very important merit that makes optical fibers so practical in long distance communications is that they are very strong and flexible. The semiconductor materials and structures are thereby required to have comparable strengths and flexibilities, if constructed inside the fibers to realize unprecedented optoelectronics functions. Microstructured optical fibers have a complex two dimensional structure of air holes running down the length. We have demonstrated infiltration of a variety of semiconductor materials into the holes via the unique high pressure chemical vapor deposition. In this presentation, we first report the control of the carrier type and concentration in Si and Ge. Based on this control, we are able to make different types of field effect transistors and realize Si/Ge pn junctions in a fiber for the first time. This should be of considerable significance since pn junctions are the basic building blocks for optoelectronics. For example, our preliminary results show that Si/Ge heterojunctions work as in-fiber photodetectors for the 1.55 µm communication light. In the presentation, we will particularly address the flexibility of these in-fiber devices. These devices are wires or tubes with diameters ranging from 0.5 to 10 µm and lengths up to several tens of centimeters. Although being of polycrystalline nature, they show remarkable flexibilities, for example, they can generally stand > 1% strain without breaking. Generally, single crystalline whiskers and nanowires have proven to have strengths close to the theoretical values. The study of the mechanical behavior of these fine grained semiconductor materials should be highly worthwhile; they may expand the material choice for the flexible electronics and optoelectronics
Templated chemically deposited semiconductor optical fiber materials
No full textChemical deposition is a powerful technology for fabrication of planar microelectronics. Optical fibers are the dominant platform for telecommunications, and devices such as fiber lasers are forming the basis for new industries. High-pressure chemical vapor deposition (HPCVD) allows for conformal layers and void-free wires of precisely doped crystalline unary and compound semiconductors inside the micro-to-nanoscale-diameter pores of microstructured optical fibers (MOFs). Drawing the fibers to serve as templates into which these semiconductor structures can be fabricated allows for geometric design flexibility that is difficult to achieve with planar fabrication. Seamless coupling of semiconductor optoelectronic and photonic devices with existing fiber infrastructure thus becomes possible, facilitating all-fiber technological approaches. The deposition techniques also allow for a wider range of semiconductor materials compositions to be exploited than is possible by means of preform drawing. Gigahertz bandwidth junction-based fiber devices can be fabricated from doped crystalline semiconductors, for example. Deposition of amorphous hydrogenated silicon, which cannot be drawn, allows for the exploitation of strong nonlinear optical function in fibers. Finally, crystalline compound semiconductor fiber cores hold promise for high-power infrared light-guiding fiber devices and subwavelength-resolution, large-area infrared imaging
Endoscopic fiber: microfluidic chemical deposition moves optical fiber to the nanoscale
No full textThe use of a novel chemical vapor-deposition process to integrate metals and semiconductor films in microstructured optical fibers may soon enable nanometer-scale waveguides and endoscopic cameras
Fusion of transparent semiconductors and microstructured optical fibers via high-pressure microfluidic chemical deposition
No full textThe introduction of a crystalline semiconductor material within the capillaries of a microstructured optical fiber (MOF) presents tremendous potential for the development of in-fiber optoelectronic devices. We have developed a high-pressure microfluidic process that allows us to adapt traditional chemical vapor deposition chemistries to incorporate materials within the capillaries of MOFs. Pressures up to 35MPa are used to force a precursor/carrier gas mixture through the capillaries enabling deposition within microscale capillaries over meters in length. The materials can be organized within the MOFs for in-fiber applications, or the MOF can be used as a template for the formation of highly uniform extreme aspect ratio tubes and wires. Our efforts in the deposition of silicon carbide within the microscale capillaries of MOFs from a single source precursor will be presented. Crystalline semiconductor materials such as SiC are of particular interest to us owing to their ability to generate light. The introduction of SiC into the capillaries presents tremendous potential for the development of in-fiber optoelectronic devices with potential applications including light generation, modulation, and amplification
Polycrystalline silicon optical fibers with atomically smooth surfaces
No full textWe investigate the surface roughness of polycrystalline silicon core optical fibers fabricated using a high-pressure chemical deposition technique. By measuring the optical transmission of two fibers with different core sizes, we will show that scattering from the core–cladding interface has a negligible effect on the losses. A Zemetrics ZeScope three-dimensional optical profiler has been used to directly measure the surface of the core material, confirming a roughness of only ±0.1nm. The ability to fabricate low-loss polysilicon optical fibers with ultrasmooth cores scalable to submicrometer dimensions should establish their use in a range of nonlinear optical application
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