Whispering Gallery Mode Resonator Stabilized Narrow Linewidth Fiber Loop Laser

We demonstrate a narrow line, fiber loop laser using Erbium-doped fiber as the gain material, stabilized by using a microsphere as a transmissive frequency selective element. Stable lasing with a linewidth of 170 kHz is observed, limited by the experimental spectral resolution. A linear increase in output power and a red-shift of the lasing mode were also observed with increasing pump power. Its potential application is also discussed

Sub-kHz lasing of a CaF_2 Whispering Gallery Mode Resonator Stabilized Fiber Ring Laser

We utilize a high quality calcium fluoride whispering-gallery-mode resonator to stabilize a simple erbium doped fiber ring laser with an emission frequency of 196 THz (wavelenght 1530 nm) to a linewidth below 650 Hz. This corresponds to a relative stability of 3.3 x 10^(-12) over 16 \mus. In order to characterize the linewidth we use two identical self-built lasers and a commercial laser to determine the individual lasing linewidth via the three-cornered hat method.Comment: 4 pages, 3 figure

The Ovaherero/Nama Genocide: A Case for an Apology and Reparations

This research examines the consequences of the Ovaherero and Nama massacres occurring in modern Namibia from 1904-08 and perpetuated by Imperial Germany. Recent political advances made by, among other groups, the Association of the Ovaherero Genocide in the United States of America, toward mutual understanding with the Federal Republic of Germany necessitates a comprehensive study about the event itself, its long-term implications, and the more current vocalization toward an apology and reparations for the Ovaherero and Nama peoples. Resulting from the Extermination Orders of 1904 and 1905 as articulated by Kaiser Wilhelm II’s Imperial Germany, over 65,000 Ovaherero and 10,000 Nama peoples perished in what was the first systematic genocide of the twentieth century. This study assesses the historical circumstances surrounding these genocidal policies carried out by Imperial Germany, and seeks to place the devastating loss of life, culture, and property within its proper historical context. The question of restorative justice also receives analysis, as this research evaluates the case made by the Ovaherero and Nama peoples in their petitions for compensation. Beyond the history of the event itself and its long-term effects, the paper adopts a comparative approach by which to integrate the Ovaherero and Nama calls for reparations into an established precedent

Neutrino spin oscillations in gravitational fields

We study neutrino spin oscillations in black hole backgrounds. In the case of a charged black hole, the maximum frequency of oscillations is a monotonically increasing function of the charge. For a rotating black hole, the maximum frequency decreases with increasing the angular momentum. In both cases, the frequency of spin oscillations decreases as the distance from the black hole grows. As a phenomenological application of our results, we study simple bipolar neutrino system which is an interesting example of collective neutrino oscillations. We show that the precession frequency of the flavor pendulum as a function of the neutrino number density will be higher for a charged/non-rotating black hole compared with a neutral/rotating black hole respectively.Comment: Replaced with the version accepted for publication in Gravitation and Cosmology, Springer. 10 pages. 4 figure

Influenza vaccines: the effect of vaccine dose on antibody response in primed populations during the ongoing interpandemic period. A review of the literature.

Health authorities tend to favour an increase of the antigen dose in inactivated influenza vaccines from or = 75%) for a 10 micrograms HA dose of influenza A vaccine components. For both response and protection rates, an increase of the antigenic load from 10 to 15 micrograms HA was not associated with a meaningful increase of seroresponse: in 38 out of 39 stratification groups, the increase of response and/or protection rate varied between -9% and +8%, with a median of 1.5%. These results do not justify the expectation that a vaccine dose of 15 micrograms HA per strain would be clinically superior to a dose of 10 micrograms HA. Only in a group of immune-compromised patients on chronic intermittent haemodialysis were results in favour of a higher dose found, which may justify further evaluation in this special population