Thickness dependence of amplified spontaneous emission in low-absorbing organic waveguides.
The effect of varying film thickness (h) on the amplified spontaneous emission (ASE) properties of 0.5  wt.% perylenediimide-doped polystyrene waveguides is reported. The threshold dependence on h, not previously investigated in detail, is analyzed in terms of the film absorption and photoluminescence, the confinement of the fundamental waveguide mode (TE0), and the presence of high-order modes. For h<400  nm and down to 150 nm, the ASE wavelength blueshifts, while the linewidth and threshold increase. The detrimental ASE operation in very thin films is due to the low absorption as well as to the poor confinement of the TE0 mode.
Instituto Universitario de Materiales de Alicante (IUMA) and Unidad Asociada UA-CSIC, Universidad de Alicante, 03080-Alicante, Spain.
Eva M
EM
Calzado
Manuel G
MG
Ramírez
Pedro G
PG
Boj
María A
MA
Díaz García
D000042:Absorption; D004867:Equipment Design; D007094:Imides / Q000737:chemistry*; D053844:Lasers, Solid-State; D008027:Light; D055095:Optics and Photonics; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry*
D007094:Imides; D011137:Polystyrenes; C521332:perylenediimide; D010569:Perylene