Near-field nano-imager

An imaging device. In one embodiment, the imaging device includes a plurality of first electrode strips in parallel to each other along a first direction x, wherein each first electrode strip has an elongated body with a first surface and an opposite, second surface and a thickness n.sub.1. The imaging device also includes a plurality of second electrode strips in parallel to each other along a second direction y that is substantially perpendicular to the first direction x, wherein each second electrode strip has an elongated body with a first surface and an opposite, second surface and a thickness n.sub.2. The plurality of second electrode strips are positioned apart from the plurality of first electrode strips along a third direction z that is substantially perpendicular to the first direction x and the second direction y such that the plurality of first electrode strips and the plurality of second electrode strips are crossing each other accordingly to form a corresponding number of crossing points. And at each crossing point, a semiconductor component is filled between the second surface of a corresponding first electrode strip and the first surface of a corresponding second electrode strip to form an addressable pixel

Applications of Genomics to Plantation Forestry with Kelampayan in Sarawak

Wood-based industries in Sarawak are increasingly encouraged to adapt to " new wood " from planted forests composed of fast-growing species such as Kelampayan with short rotation cycle (6-8 years). The rationale is that natural forests at the most produce about 3m 3 /ha/yr of commercial timber, whereas plantations can produce annually from 10m 3 /ha to 30m 3 /ha of commercial timber. It is estimated at least 30 million seedlings are required for annual planting or reforestation programmes to meet the increasing global demand for raw materials. To date, several molecular genetics studies have been completed for Kelampayan. These include genetic diversity of Kelampayan, genetic marker (SSRs) development, 'Touch-incubate-PCR' approach for preparing plant tissues for high throughput genotyping, and transcriptomics and bioinformatics on wood formation of Kelampayan. This information provides a useful resource for genomic selection of Kelampayan aiming at the production of high value forests for maximum returns

Distributed Bragg reflectors and devices incorporating same

Distributed Bragg Reflectors of high efficacy based on alternating layers of large difference in refractive index are fabricated by epitaxial growth followed by etchant removal and back-filling to produce a structure in which alternation is between layers of retained epitaxially grown material and layers of back-filled material. Such reflectors may serve simply as mirrors or may be incorporated in a variety of devices including lasers, LEDs, detectors, optical switches in which the DBRs serve e.g. for cavitation.Published versio

Simulation of photodetection using finite-difference time-domain method with application to near-field subwavelength imaging based on nanoscale semiconductor photodetector array

Simulation of detecting photoelectrons using multi-level multi-electron (MLME) finite-difference time-domain (FDTD) method with an application to near-field subwavelength imaging based on semiconductor nanophotodetector (NPD) array is reported. The photocurrents from the photodiode pixels are obtained to explore the resolution of this novel NPD device for subwavelength imaging. One limiting factor of the NPD device is the optical power coupling between adjacent detector pixels. We investigate such power coupling in the presence of absorbing media as well as the spatial distributions of the electric field and photoelectron density using the MLME FDTD simulation. Our results show that the detection resolution is about one tenth of the operating wavelength, which is comparable to that of a near-field scanning optical microscope based on metal clad tapered fiber.Comment: 7 pages, 4 figure

Low-Voltage Electro-Optic Modulator Structure using Transparent Conducting Oxide with High Conductivity-Loss Ratio as Electrodes

Abstract: We describe a novel design of electro-optical modulator using transparent conducting oxide (TCO) with high σ/α ratio as electrode. We show that by engineering TCO's σ/α ratio, both low voltage and high-speed can be achieved

Chaotic Microcavity Laser with Low threshold and Unidirectional Output

Here we report lasing action in lima\c{c}on-shaped GaAs microdisks with quantum dots (QDs) embedded. Although the intracavity ray dynamics is predominantly chaotic, high-$Q$ modes are concentrated in the region $\chi > \chi_c$ as a result of wave localization. Strong optical confinement by total internal reflection leads to very low lasing threshold. Our measurements show that all the lasing modes have output in the same direction, regardless of their wavelengths and intracavity mode structures. This universal emission direction is determined by directed phase space flow of optical rays in the open chaotic cavity. The divergence angle of output beam is less than 40 degree. The unidirectionality proves to be robust against small deviations of the real cavity shape and size from the designed values.Comment: 12 pages, 4 figure

In Silico Analysis of Cellulose Synthase Gene (NcCesA1) in Developing Xylem Tissues of Neolamarckia Cadamba

This study reported the isolation and in silico characterization of full-length cellulose synthase (CesA) cDNA from Neolamarckia cadamba, an important tropical plantation tree species. CesA is a member of processive glycosyltransferases that involved in cellulose biosynthesis of plants. CesA acts as a central catalyst in the generation of plant cell wall biomass or cellulose. It also plays an important role in regulating wood formation. The hypothetical full-length CesA cDNA (NcCesA1; JX134621) was assembled by contig mapping approach using the CesA cDNA sequences from NcdbEST and the amplified 5�-and 3�-RACE PCR sequences. The NcCesA1 cDNA has a length of 3,472 bp with 3,126 bp open reading frame encoding a 1,042 amino acid sequence. The predicted NcCesA1 protein contained N-terminal cysteine rich zinc binding domain, 7 putative Transmembrane Helices (TMH), 4 U-motifs that contain a signature D, D, D, QxxRW motif, an alternating Conserved Region (CR-P) and 2 Hypervariable Regions (HVR). These entire shared domain structures suggest the functional role of NcCesA1 is involved in glycosyltransferation of the secondary cell wall cellulose biosynthesis of N. cadamba. Sequence comparison also revealed the high similarity (90%) among NcCesA1 and PtrCesA2 of Populus tremuloides. This further implies the involvement of NcCesA1 that catalyzes the cellulose biosynthesis of secondary cell wall rather than primary cell wall. This full-length NcCesA1 cDNA can serve as good candidate gene in association genetics study which leads to Gene-Assisted Selection (GAS) in the N. cadamba tree breeding programme. Furthermore, the isolation of new CesA genes from tropical tree genomes is essential for enhancing knowledge of cellulose biosynthesis in trees that has many fundamental and commercial implications

Bioinformatics Analysis of Xyloglucan Endotransglycosylase/Hydrolase (XTH) Gene from Developing Xylem of a Tropical Timber Tree Neolamarckia Cadamba

This study reported the isolation and in silico characterization of a full-length Xyloglucan endotransglycosylase/Hydrolase (XTH) cDNA from Neolamarckia cadamba, an important tropical light hardwood plantation tree species. XTH is considered as a key agent to regulate cell wall expansion and is believed to be responsible for the incorporation of newly synthesised xyloglucan into the wall matrix. The full-length of NcXTH was firstly predicted using the XTH singletons from the NcdbEST through contig mapping approach. Further validation and confirmation were conducted by amplifying the full-length XTH cDNA using RT-PCR approach. Two fulllength XTH cDNAs, namely NcXTH1 (JX134619) and NcXTH2 (JX134620) were discovered and the nucleotide sequences were 893 and 1,024 bp in length, respectively. The open reading frames for NcXTH1 and NcXTH2 were 858 and 915 bp, respectively. Results predicted that NcXTH1 and NcXTH2 proteins carry out XET activity but they are from different XTH family members. This full-length NcXTH cDNA can serve as good candidate genes in association genetics study which leads to Gene-Assisted Selection (GAS) in the N. cadamba tree breeding programme

Applications Of Genomics To Plantation Forestry With Kelampayan In Sarawak

Wood-based industries in Sarawak are increasingly encouraged to adapt to “new wood” from planted forests composed of fast-growing species such as Kelampayan with short rotation cycle (6-8 years). The rationale is that natural forests at the most produce about 3m3 /ha/yr of commercial timber, whereas plantations can produce annually from 10m3 /ha to 30m3 /ha of commercial timber. It is estimated at least 30 million seedlings are required for annual planting or reforestation programmes to meet the increasing global demand for raw materials. To date, several molecular genetics studies have been completed for Kelampayan. These include genetic diversity of Kelampayan, genetic marker (SSRs) development, ‘Touch-incubate-PCR’ approach for preparing plant tissues for high throughput genotyping, and transcriptomics and bioinformatics on wood formation of Kelampayan. This information provides a useful resource for genomic selection of Kelampayan aiming at the production of high value forests for maximum returns