Artigo de peri??dico
Polydispersed powders (Nd3+:YVO4) for ultra efficient random lasers
Registro en:
0934-0866
4
35
10.1002/ppsc.201700335
70.392
85.00
Autor
WETTER, NIKLAUS U.
GIEHL, JULIA M.
BUTZBACH, FELIX
ANACLETO, DANILO
JIMENEZ-VILLAR, ERNESTO
Resumen
Random lasers hold the potential for cheap, coherent light sources that can
be miniaturized and molded into any shape with several other added benefits
such as speckle-free imaging; however, they require improvements specifically
in terms of efficiency. This paper details for the first time a strategy for
increasing the efficiency of a random laser that consists in using smaller particles,
trapped between large particles to serve as absorption and gain centers
whereas the large particles control mainly the light diffusion into the sample.
Measurements of backscattering cone, sample absorption, reflection, and
laser emission are used to determine the samples??? transport mean free path,
fill fractions, laser efficiency, and the average photon path lengths inside the
scattering medium for backscattered pump photons. A record slope efficiency
of 50% is reached by optimizing pump photon diffusion and absorption in a
powder pellet composed by a polydispersed particle size distribution (smaller
particles between bigger ones) from a grinded and sieved 1.33 mol% yttrium
vanadate doped with neodymium crystal with mean particle size of 54 ??m. Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) FAPESP: 12/18162-4; 12/05141- 9; 14/05965-7; 17/05854-9