Vol. 41, Issue 1, pp. 269-271 (2011)

Abstract

The relation between spontaneous and induced emission, and to some extend amplified spontaneous emission in an optical fiber, due to its very elongated active media shape (pencil-like shape) is different as compared to small dimension laser active media (like ruby, neodymium glass, semiconductors, etc.) We have measured the relation between the laser emission and the spontaneous side emission in an erbium doped ZBLAN fiber and found that the spontaneous side emission did not decrease at the laser threshold. In this way, there is no sharp jump in intensity, measured at the fiber terminal when crossing the laser threshold. Furthermore, there is no competition between the spontaneous emission and the laser one.