Abstract
We report on amplification of blue light (469 nm) via amplified spontaneous emission in asymmetric planar waveguides of a fully arylated polyindenofluorene derivative. A very low threshold value of about
3
μ
J
∕
cm
2
(
∼
375
W
∕
cm
2
)
for amplification of light has been demonstrated by pumping the waveguides at 3.0 eV (410 nm) with a stripe shape excitation beam. Moderate gain coefficients up to
21
cm
−
1
and loss coefficients around
6
cm
−
1
have been measured. All measurements were performed under ambient conditions. No sample degradation could be observed which testifies to the excellent stability of the material against photodegradation.