A method is reported for fabricating truly three-dimensional micro-photonic structures directly onto the end face of an optical fiber using the cross-linkable resist SU-8. This epoxide-based material is well suited for micro-device fabrication because it is photo-processed as a solid and the cross-linked material is mechanically robust, chemically resistant, and optically transparent. Yet, procedures commonly used to process SU-8, particularly spin-coating, are impractical when the intended fabrication substrate is the end-face of an optical fiber. A melt-reflow process was developed to prepare optical fibers having SU-8 resin deposited at controlled thickness on the fiber end-face. Multi-photon direct laser writing was then used to fabricate various refractive lenses, a compound lens system, and a woodpile photonic crystal within the resin on the end-face of the optical fiber. Data are presented that show how the refractive lenses can be used to alter the output of the optical fiber. This work opens a new path to low-profile integrated photonic devices.

The single halide as well as the majority of the mixed halide nanocrystals do not show luminescence intermittency.

A new fluorescence-based method for inbred haploid differentiation in maize kernels was developed by utilizing the R1-nj colour marker in combination with fluorescence microspectroscopy and imaging. Seven inbred lines with varying R1-nj expression were used in this study. The fluorescence response of the diploid kernels at the embryonic dye spot was shown to simultaneously exhibit lower intensity and occur at a higher wavelength than the fluorescence of the dye-lacking haploid embryos. Intensity and area thresholds were applied to fluorescence images to sort the haploids from mixed sample populations, and sorting efficiencies of greater than 80% were achieved in all seven inbred lines (with values greater than 90% for five lines). The potential for highthroughput sorting when fluorescence imaging is combined with existing technologies for seed handling as well as high sorting efficiency may make fluorescence a viable and promising alternative to current sorting methods for some inbred lines.Key words: maize -haploid -diploid -fluorescencesortingThe development of new hybrids of maize (Zea mays L.) with desirable traits (e.g. high yield, pest tolerance) is of considerable importance to the global economy, with the 2014 worldwide production estimated at 1.02 billion metric tons (FAO 2014). In modern commercial maize breeding programmes, new hybrids are generated by crossing homozygous inbred lines that have been produced via doubled haploid (DH) line development (Murigneux et al. 1993, R€ ober et al. 2005, Prasanna 2012). Traditional inbred line development via manual self-pollination requires 6-8 generations to produce a highly homozygous line, whereas DH line development only requires 2-3 generations for a 100% homozygous line. This reduction in line development time allows breeders not only to produce more inbred lines in less time, but also to react to new selection targets quickly. In the DH process, the haploid kernels need to be collected from the mixed population as only the haploids are suitable for the next generation of inbreeding.Most methods for haploid kernel selection rely on pioneering work by Nanda and Chase, who used purple embryo marker (PEM) stock as the male parent to produce the anthocyanin marker R1-Navajo (R1-nj) in the progeny kernels (Nanda and Chase 1966). The dominantly inherited R1-nj marker causes a xenia effect resulting in pigmentation of the embryo and on the cap of the aleurone of the seed. As is the case in many angiosperms, sexual reproduction occurs through the double fertilization process where fusion of one sperm and the egg constitutes the union of genetic information that produces the diploid embryo, while union of the second sperm and the central cells develops into triploid endosperm. The DH system takes advantage of the phenomenon of haploid induction. In this case, it is known as maternal haploid induction because haploid embryos contain the cytoplasm of the female (donor) parent and the inducer line is the male in the cross. On average, 10% of double fertilizati...