A Broadband Scalar Vortex Coronagraph

Broadband coronagraphy with deep nulling and small inner working angle has the potential of delivering images and spectra of exoplanets and other faint objects. In recent years, many coronagraphic schemes have been proposed, the most promising being the optical vortex phase mask coronagraphs. In this paper, a new scheme of broadband optical scalar vortex coronagraph is proposed and characterized experimentally in the laboratory. Our setup employs a pair of computer generated phase gratings (one of them containing a singularity) to control the chromatic dispersion of phase plates and achieves a constant peak-to-peak attenuation below $1\cdot 10^{-3}$ over a bandwidth of 120 nm centered at 700 nm. An inner working angle of ~\lambda/D is demonstrated along with a raw contrast of 11.5 magnitudes at 2\lambda/D.Comment: Accepted, 6 pages, 6 image

Quasi 2D Bose-Einstein condensation in an optical lattice

We study the phase transition of a gas of Rb atoms to quantum degeneracy in the combined potential of a harmonically confining magnetic trap and the periodic potential of an optical lattice. For high optical lattice potentials we observe a significant change in the temperature dependency of the population of the ground state of the system. The experimental results are explained by the subsequent formation of quasi 2D condensates in the single lattice sites.Comment: 7 pages (including 3 figures

Λ{\Lambda}-enhanced grey molasses on the D2D_2 transition of Rubidium-87 atoms

Laser cooling based on dark states, i.e. states decoupled from light, has proven to be effective to increase the phase-space density of cold trapped atoms. Dark-states cooling requires open atomic transitions, in contrast to the ordinary laser cooling used for example in magneto-optical traps (MOTs), which operate on closed atomic transitions. For alkali atoms, dark-states cooling is therefore commonly operated on the $D_1$ transition $n S_{1/2}\rightarrow n P_{1/2}$. We show that, for $^{87}\text{Rb}$, thanks to the large hyperfine structure separations the use of this transition is not strictly necessary and that $"$quasi-dark state$"$ cooling is efficient also on the $D_2$ line, $5 S_{1/2}\rightarrow 5 P_{3/2}$. We report temperatures as low as $(4.0\pm 0.3)\,\mu$K and an increase of almost an order of magnitude in the phase space density with respect to ordinary laser sub-Doppler cooling

MUATAN TITIK NOL BERBAGAI BAHAN ORGANIK, PENGARUHNYA TERHADAP KAPASITAS TUKAR KATION DI LAHAN TERDEGRADASI

Zero Point of Charge (ZPC) is an important variable in describing the mechanism of reversible surface charge primarily on weathered soil dominated by variable charge. The presence of organic matter effect on the nature of the charge in the soil. Research goals include: 1). Obtaining information kinds of organic matter with a low pho, 2) Knowing the behavior of pHo and net charge in the ground, 3) Knowing the influence of pHo on the soil cation exchange capacity and 4) Knowing the influence of a variety of organic fertilizer on peanut yield.This study is an experimental functional relationship variables approach through experiments. The experiments were conducted at Greenhouse, the basic design used was completely randomized design of a single factor, namely: each treatment is repeated 3 times. The treatment is done as follows: P0 = soil without the addition of organic fertilizers, P1 = soil with the addition of cow manure 5 tons / ha, P2 = soil with the addition of chicken manure 5 tons / ha, P3 = soil with the addition of five quail manure tonnes / ha, P4 = soil with the addition of goat manure 5 tons / ha, P5 = soil with the addition of bokashi 5 tons / ha, P6 = soil with the addition of rice straw compost 5 tons / ha, P7 = soil by adding compost hyacinth 5 ton / ha. P8 = soil by adding compost Titonia 5 tons / ha and each treatment was repeated 3 times. Analysis of the quality of organic fertilizers include: levels of lignin and polyphenols, C/N, pH , pHo, humic acid and fulvic acid. The soil analysis includes the C-organic soil, total N, C / N, pH , pHo, CEC, The results showed that the zero point ofcharge (pHo) is the lowest organic fertilizer chicken manure (4.52). Obtained a close relationship between the difference in pH H2O with pHo with cation exchange capacity. Highest cation exchange capacity achieved in the treatment of chicken manure. Keywords: zero point of charge, pHo, CEC, organic fertilize

Pelatihan Pengembangan Media Pembelajaran Interaktif dengan Power Point untuk Peningkatan Kompetensi Guru SD

Perkembangan Teknologi Informasi di dunia pendidikan khususnya pendidikan dasar atau sekolah dasar ternyata tidak diiringi dengan kemampuan guru dalam memanfaatkan teknologi informasi tersebut, penggunaan media pembelajaran power point masih belum di maksimalkan oleh guru SD di lingkungan UPTD Pendidikan Semarang Selatan, Pengabdian masyarakat yang dilakukakan memang sangat diharapkan oleh UPTD Pendidikan Semarang Selatan guna meningkatkan kompetensi guru seiring dengan mulai diterapkannya SDC (Semarang Digital Class), metode yang digunakan dalam pengabdian masyarakat ini adalah identifikasi, pelatihan dan pendampingan, pelatihan diikuti oleh 22 guru SD dengan materi pembuatan media pembelajaran interaktif menggunakan power point, setelah pelatihan diadakan evaluasi pembuatan media pembelajaran yang interaktif, kemudian diadakan pendampingan ke SD untuk melihat penerapan hasil pelatihan, disamping pendampingan juga diadakan lomba dengan kriteria terbaik dalam pembuatan media pembelajaran, diharapkan guru semakin kreatif sehingga tujuan peningkatan kompetensi guru dapat dicapai

The Assessment of Soil Quality of Various Age of Land Reclamation After Coal Mining: a Chronosequence Study

The assessment of soil quality index is one of the parameters to evaluate the goal of land reclamation. The research has been done in the various age of soil of PT Adaro Indonesia and natural forest. The research used descriptive explorative method and open field survey. Purposive sampling was used to take the sample in research location that represented the condition of every location. Principal component analysis used to know the main indicator. The main indicator was based on Eigen value >1 and chosen by indicator correlation having the highest weight index. The main indicator chosen was called minimum data set. The result of the research showed that minimum data set consisted of pH, base saturation, bulk density, electrical conductivity, cation exchange capacity, available P, total N, and soil organic carbon. The main indicators contributing to soil quality index value were total N and cation exchange capacity. Variable linear analysis showed that the longer age of land reclamation was followed by the development of soil quality index. Soil quality index in 18 years old soil reclamation (0.651) was higher than that in natural forest (0.575). Soil quality index of > 0.5 is defined as sustainable reclamation

Three dimensional imaging of short pulses

We exploit a slightly noncollinear second-harmonic cross-correlation scheme to map the 3D space-time intensity distribution of an unknown complex-shaped ultrashort optical pulse. We show the capability of the technique to reconstruct both the amplitude and the phase of the field through the coherence of the nonlinear interaction down to a resolution of 10 $\mu$m in space and 200 fs in time. This implies that the concept of second-harmonic holography can be employed down to the sub-ps time scale, and used to discuss the features of the technique in terms of the reconstructed fields.Comment: 16 pages, 6 figure