Designing and understanding directional emission from spiral microlasers.

Opt Lett

Max-Planck-Institut fur Physik komplexer Systeme, Dresden, Germany.

Published: January 2009

The availability of microlasers with highly directional far-field characteristics is crucial for future applications. To this end we study the far-field emission of active microcavities with a spiral shape using the Schrödinger-Bloch model. We find that they can provide directional emission under the conditions of (i) pumping along the resonator boundary and (ii) for specific resonator geometries. We systematically study the far-field characteristics under variation of the pumped area and the cavity geometry and identify a directionality optimized regime. Our results consistently explain previously obtained experimental results.

Download full-text PDF

Source
http://dx.doi.org/10.1364/ol.34.000163DOI Listing

Publication Analysis

Top Keywords

directional emission
8
far-field characteristics
8
study far-field
8
designing understanding
4
understanding directional
4
emission spiral
4
spiral microlasers
4
microlasers availability
4
availability microlasers
4
microlasers highly
4

Similar Publications

Paddy fields are a major anthropogenic source of global methane (CH) emissions, a powerful greenhouse gas (GHG). This study aimed at gaining insights of different organic and inorganic conductive materials (CMs) - biochar, fungal melanin, and magnetite - to mitigate CH emissions, and on their influence on key microbial populations, mimicking the postharvest season throughout the degradation of rice straw in microcosms under anaerobic conditions encompassing postharvest paddy rice soils from the Ebro Delta, Spain. Results showed that fungal melanin was the most effective CM, significantly reducing CH emissions by 29 %, while biochar amendment also reduced emissions by 10 %.

View Article and Find Full Text PDF

High-resolution cryo-electron microscopy (cryo-EM) requires costly 200- to 300-keV cryo-transmission electron microscopes (cryo-TEMs) with field emission gun (FEG) sources, stable columns, constant-powered lenses, autoloader, and direct electron detectors (DED). Recent advances in 100-keV imaging with the emergence of sub-200-keV optimized DED technology promises the development of more affordable cryo-TEMs. So far, 100-keV imaging has required microscopes with FEG sources.

View Article and Find Full Text PDF

Background: The accumulation of misfolded tau proteins, an Alzheimer's disease (AD) hallmark, starts decades before the emergence of cognitive decline and clinical diagnosis. Autopsy studies support a predictable progression of tau pathology through large-scale systems. However, less is known about the specific progression patterns.

View Article and Find Full Text PDF

Background: Gaining insight into the emotional consequences of disclosing amyloid Positron Emission Tomography (PET) results is essential for offering effective support to patients of varying cognitive status. This analysis aimed to examine variations in emotional distress levels following the disclosure of amyloid PET results among participants that are cognitively normal, with Mild Cognitive Impairment (MCI), or dementia.

Method: This investigation was a preliminary analysis of 55 participants, using 1-month follow-up call data of an ongoing brain imaging data repository study, obtaining baseline PET imaging on a subset of Alzheimer's Disease Research Center (ADRC) participants.

View Article and Find Full Text PDF

Clinical Manifestations.

Alzheimers Dement

December 2024

Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.

Background: Practice effects on cognitive testing in Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD) remain understudied, especially with how they compare to biomarkers of AD. The current study sought to add to this growing literature.

Method: Cognitively intact older adults (n = 68), those with amnestic MCI (n = 52), and those with mild AD (n = 45) repeated a brief battery of cognitive tests twice across one week, and they also completed a baseline amyloid PET scan, a baseline MRI, and a baseline blood draw to obtain APOE e4 status.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!