Effects of pump geometry and mutual orientation of absorption and emission dipoles on stimulated emission characteristics of dye solutions

1988 ◽  
Vol 49 (1) ◽  
pp. 682-686
Author(s):  
V. A. Gaisenok ◽  
V. V. Gruzinskii ◽  
G. G. Krylov
Keyword(s):  
Stimulated Emission ◽  
Mutual Orientation ◽  
Emission Characteristics ◽  
Absorption And Emission ◽  
Dye Solutions

Tracing absorption and emission characteristics of halogen-bonded ion pairs involving halogenated imidazolium species

2021 ◽  
Vol 23 (12) ◽  
pp. 7480-7494
Author(s):  
Sarah Karbalaei Khani ◽  
Bastian Geissler ◽  
Elric Engelage ◽  
Patrick Nuernberger ◽  
Christof Hättig
Keyword(s):  
Ion Pairs ◽  
Ion Pairing ◽  
Emission Characteristics ◽  
Absorption And Emission ◽  
Spectroscopic Signatures

Spectroscopic signatures of ion-pairing are identified by variation of counterion and substitution and comparison with theory.

Light Emission Properties of GaN-Based Double Heterostructures and Quantum Wells

1995 ◽  
Vol 395 ◽  
Author(s):  
D.A.S. Loeber ◽  
J.M. Redwing ◽  
N.G. Anderson ◽  
M.A. Tischler
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Stimulated Emission ◽  
Pump Light ◽  
Band Edge Emission ◽  
Emission Characteristics ◽  
Nitrogen Laser ◽  
Edge Emission ◽  
Edge Luminescence ◽  
Double Heterostructures

ABSTRACTEdge emission characteristics of optically pumped GaN-AlGaN double heterostructures and quantum wells are examined. The samples, which were grown by metalorganic vapor phase epitaxy, are photoexcited with light from a pulsed nitrogen laser. The pump light is focused to a narrow stripe on the sample surface, oriented perpendicular to a cleaved edge, and the edge luminescence is collected and analyzed. We first compare emission characteristics of highly excited GaN-AlGaN double heterostructures grown simultaneously on SiC and sapphire substrates. Polarization resolved spectral properties of edge luminescence from both structures is studied as a function of pump intensity and excitation stripe length. Characteristics indicative of stimulated emission are observed, particularly in the sample grown on SiC. We then present results demonstrating laser emission from a GaN-AlGaN separate-confinement quantum-well heterostructure. At high pump intensities, band edge emission from the quantum well exhibits five narrow (∼1 Å) modes which are evenly spaced by 10Å to within the resolution of the spectrometer. This represents the first demonstration of laser action in a GaN-based quantum-well structure.

Amplitude-spectral asymmetry of stimulated emission from dye solutions

1978 ◽  
Vol 8 (2) ◽  
pp. 169-173
Author(s):  
V I Bezrodnyĭ ◽  
N M Narovlyanskaya ◽  
E A Tikhonov
Keyword(s):  
Stimulated Emission ◽  
Spectral Asymmetry ◽  
Dye Solutions

Structural and stimulated emission characteristics of diameter-controlled ZnO nanowires using buffer structure

2009 ◽  
Vol 42 (22) ◽  
pp. 225403 ◽  
Author(s):  
Sang Hyun Lee ◽  
Seogwoo Lee ◽  
Jun-Seok Ha ◽  
Hyo-Jong Lee ◽  
Jae Wook Lee ◽  
...  
Keyword(s):  
Zno Nanowires ◽  
Stimulated Emission ◽  
Emission Characteristics ◽  
Buffer Structure

Stimulated emission characteristics of InGaN/GaN multiple quantum wells: Excitation length and excitation density dependence

1998 ◽  
Vol 73 (25) ◽  
pp. 3689-3691 ◽  
Author(s):  
T. J. Schmidt ◽  
S. Bidnyk ◽  
Yong-Hoon Cho ◽  
A. J. Fischer ◽  
J. J. Song ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Density Dependence ◽  
Stimulated Emission ◽  
Multiple Quantum Wells ◽  
Excitation Density ◽  
Emission Characteristics ◽  
Multiple Quantum

scholarly journals Biofluorescent Worlds – II. Biological fluorescence induced by stellar UV flares, a new temporal biosignature

2019 ◽  
Vol 488 (4) ◽  
pp. 4530-4545 ◽  
Author(s):  
Jack T O'Malley-James ◽  
Lisa Kaltenegger
Keyword(s):  
Cloud Cover ◽  
Visible Spectrum ◽  
Uv Protection ◽  
Emission Characteristics ◽  
Large Telescope ◽  
Atmospheric Absorption ◽  
Absorption And Emission ◽  
Temporary Change ◽  
Fluorescent State ◽  
M Stars

ABSTRACT Our first targets in the search for signs of life are orbiting nearby M stars, such as the planets in the Proxima Centauri, Ross-128, LHS-1140, and TRAPPIST-1 systems. Future ground-based discoveries, and those from the TESS mission, will provide additional close-by targets. However, young M stars tend to be very active, flaring frequently and causing UV fluxes on the surfaces of HZ planets to become biologically harmful. Common UV-protection methods used by life (e.g. living underground, or underwater) would make a biosphere harder to detect. However, photoprotective biofluorescence, ‘up-shifting’ UV to longer, safer wavelengths, could increase a biosphere's detectability. Here we model intermittent emission at specific wavelengths in the visible spectrum caused by biofluorescence as a new temporal biosignature for planets around active M stars. We use the absorption and emission characteristics of common coral fluorescent pigments and proteins to create model spectra and colours for an Earth-like planet in such a system, accounting for different surface features, atmospheric absorption, and cloud cover. We find that for a cloud-free planet biofluorescence could induce a temporary change in brightness that is significantly higher than the reflected flux alone, causing up to two orders-of-magnitude change in planet–star contrast, compared to a non-fluorescent state, if the surface is fully covered by a highly efficient fluorescent biosphere. Hence, UV-flare induced biofluorescence presents previously unexplored possibilities for a new temporal biosignature that could be detectable by instruments like those planned for the extremely large telescope and could reveal hidden biospheres.

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