In this paper, we demonstrate a distributed Bragg reflector (DBR) based on nanoporous anodic
aluminum oxide (AAO) formed by pulse anodization. The AAO structure with alternating
mild anodized (MA) and hard anodized (HA) layers having different porosities and thereby
different refractive indices was fabricated in 0.3 M H
2
SO
4
using potential pulses of 25 and
35 V. The effective refractive index of the HA layers can be tailored by changing the porosity
of the HA layers. The porosity of the HA layers can be significantly increased by selective
chemical etching of HA segments in 0.52 M H
3
PO
4
. Before etching, the porous AAO
structure was supported by a polymer nanorod frame. On the selected surface area pores were
infiltrated with polymers (polystyrene and PMMA). The designed AAO structure consists of
alternating high and low refractive index layers and behaves as a distributed Bragg mirror
reflecting light in two different ranges of wavelength. This behavior is extremely important in
optical communication lines where two separate spectral bands of high reflectivity in the
infrared region are desired.
departmental parameterization:
35
affiliation:
Wydział Chemii : Zakład Chemii Fizycznej i Elektrochemii