Generation of fiber-coupled, nondegenerate, polarization-entangled photons for quantum communication

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2009.Page 42 blank.Includes bibliographical references.The production of polarization-entangled photon pairs from spontaneous parametric downconversion (SPDC) enables many applications of quantum information processing. In this thesis, we use type-0 phase-matched downconversion of pump photons from a 532 nm continuous-wave laser to generate 798 nm signal and 1.6 tim idler photon pairs in periodically-poled, congruent lithium niobate (PPLN). Difference frequency generation of 798 nm is used for characterizing PPLN, including phase matching bandwidth and effective nonlinear coefficient. Optimal focusing for generating a single spatial mode SPDC output allows efficient coupling of signal and idler photons. Through coincidence counting, our source's spectral brightness is measured to be 3.6 x 105 Hz/mW/nm detected pairs/s/mW of pump power per nm of output photon bandwidth with an idler conditional detection efficiency of 1.6%. This work is a significant first step toward realizing a high-flux source of nondegenerate polarization-entangled photons.by Bhaskar Mookerji.S.B

Polarization entanglement storage in ensemble-based atomic memories

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 83-85).Quantum networks enable the long-distance communication of quantum states through teleportation, but require, in advance, the robust distribution of entanglement between relevant parties. Engineering these networks requires quantum interconnects, which convert quantum states in one physical system to those of another reversibly, and with high fidelity. In this thesis, we describe implementations of long-distance quantum communication networks using polarization entanglement and atomic ensembles. We concisely describe the interactions of a quantum optical field with a heralding atomic ensemble, accounting for multiple-pair events at entanglement generation, as well as finite transmission and photodetection efficiencies under number-resolving and non-resolving photodetection schemes. Using these results, we perform a detailed quantitative performance analysis of quantum networks that distribute and swap entanglement.by Bhaskar Mookerji.M.Eng

Subjugated to What Extent? Women in the Workplace Today in the United Arab Emirates

The black veil is still by and large in place, but is the woman behind it in the stereotyped position of subjugation and dominance that much of the world associates with her, especially in the workplace? This article examines the position of Muslim women in the workplace in one of the richest Gulf countries, the United Arab Emirates (UAE)

The optical constants of plutonium metal between .7 and 4.3 eV measured by spectroscopic ellipsometry using a double-windowed experimental chamber.

A double-windowed vacuum-tight experimental chamber was developed, and calibrated on the spectroscopic ellipsometer over the energy range from .7 to 4.5 eV using a silicon wafer with approximately 25 nm oxide thickness to remove the multiple-window effects from measurements. The ellipsometric measurements were done such that incident and exit beam were at 65 degree from surface normal. The plutonium sample (3 mm diameter, .1 mm thick) was electro-polished and mounted into the sample chamber in a glove box having a nitrogen atmosphere with less than 100ppm moisture and oxygen content. The index of refraction n and the extinction coefficient k decrease from 3.7 to 1 and 5.5 to 1.1 respectively as the photon energy increases from .7 to 4.3 eV

Effects of the timing of initial feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae

The effects of delayed first feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae were examined under controlled conditions. Morphometric characters [yolk-sac volume, oil globule volume, head depth ( H D ), body depth ( B D ), eye diameter ( E D ), musculature height ( M H ), mouth diameter ( M D ) and total length ( L T )], body mass ( M ), specific growth rate ( S GR ) and survival were evaluated under different first-feeding time (2, 3, 4 and 5 days after hatching). Larvae began to feed exogenously at 2 days after hatching (DAH) and the point of no return ( P NR ) occurred between 5 and 6 DAH at 23° C, range ±1·0° C. The yolk volume of larvae first-fed at 2 days had a significant difference compared with that of larvae first-fed at 3, 4 and 5 days on 3 and 4 DAH. The larvae first-fed at 2 days achieved comparatively better growth performance than that of 3, 4 and 5 days. On 5 DAH, all morphometric characters had significant differences between 2 and 5 days and 2 and 4 days initial feeding, respectively. Total mortality was recorded on 9 DAH for the larvae first-fed at 5 days. On 12 DAH, significant differences were observed between 2 and 4 days and 3 and 4 days initial feeding for all morphometric characters. From 16 DAH to the end of experiment, all growth variables of the larvae first-fed at 2 days were significantly higher than those in other treatments. The S GR (2–9 DAH) first-fed at 2 and 3 days were significantly higher than 4 and 5 day treatments, and the S GR (9–16 DAH) first-fed at 2 days was significantly higher than 3 and 4 day treatments. There was no significant difference, however, of S GR (16–28 DAH) among treatments. Survival rate was significantly higher at 2 days initial feeding (27·42%) when compared with 3 (15·96%) and 4 days (7·92%) initial feeding at the end of experiment. The present study suggests that the first feeding of S. scherzeri larvae should be initiated at 2 days after hatching for achieving good growth and survival.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78713/1/j.1095-8649.2009.02328.x.pd

Yolk utilization and growth during the early larval life of the Silver Perch, Bidyanus bidyanus (Mitchell, 1838)

The aim of this research was to investigate the yolk sac and oil globule utilization by silver perch (Bidyanus bidyanus) larvae produced from domesticated broodfish. The larvae were kept unfed in the holding tank, sampled, and investigated by image analysis software to determine various characteristics, such as the diameters of ova, water-hardened eggs, yolk-sac, oil globules, and the total length of larvae. The research illustrated that, with the exception of oil globule diameter, all other morphometric parameters were significantly lower (P < 0.05) when compared to the larvae from the wild broodfish. The yolk sac was completely absorbed at 96 h post-hatching (hph) and the oil globule was visible until 240 hph. The larvae exhibited predatory movements and tried to catch rotifer at 4 days post hatching (dph). However, the onset of feeding took place at 5 dph, while 100% of feeding occurred at 6 dph. During the first 96 h (h), larvae grew significantly faster than the next 144 h. Larvae encountered low mortalities (<10%) during the first 96 hph, before increasing significantly in the next 24 h and no unfed larvae survived post 240 h. The results also suggested that the exogenous feed should be available at 96 hph, which is well after the yolk sac is completely depleted. In addition, although most of eggs and larval performance from domesticated broodfish were inferior compared to the wild one, it has larger oil globule that could make longer of its mixed feeding period and therefore could have better in viability

The Deliverance of the Lord of Elephants by Krishna depicted in a sunken panel or niche of Deogarh temple

Rowland, pp, 135-6, says that the cella was originally surrounded by four porticoes, one leading to the sanctuary, the other three serving to set off and protect the reliefs of Brahmanic subjects set in the walls, These panels are deeply sunk in an elaborate framework of pilasters of the Indian order and a frieze of foliate scrolls and lion heads, The carving of the frame complements the richness of the reliefs, Their baroque depth in their box-like settings gives the effect of a spectacle on a stage and seems to prophesy the dynamic chiaroscuro of later Hindu sculpture, Reminiscent of Buddhist Gupta sculpture at Sarnath, But the richness and dramatic conception of relief are far more moving than anything to be found in Buddhist art of the 5th and sixth centuries, and are an unmistakable indication of the real renaissance that was taking place in the art of the Hindu Church

Subjugated to What Extent? Women in the Workplace Today in the United Arab Emirates

The black veil is still by and large in place, but is the woman behind it in the stereotyped position of subjugation and dominance that much of the world associates with her, especially in the workplace? This article examines the position of Muslim women in the workplace in one of the richest Gulf countries, the United Arab Emirates (UAE)