Absorption spectrum of the PbS-doped silica fibers fabricated by ALD and MCVD

摘要

The technique of atomic layer deposition (ALD) has been introduced to fabricate PbS-doped silica fibers, whose absorption peaks are discovered to be shifted from 1230 nm to 920 nm when the number of ALD deposition cycles varies from 80 to 30 during optical fiber preform fabrication. This is explained by suggesting that the PbS doped in fiber are under the 3D quantum confinement, i.e., quantum dots (QDs). An effective-mass approximation of the PbS QDs' sizes is then made to showthe shift of absorption peaks can be attributed to the change of size distribution of these dots.