Development of novel infrared filters for the next generation of astronomical telescopes and planetary probes
The spectral design and physical construction of interference thin-film multilayers for
the Q-band region of infrared filters in the 20-40μm wavelength range has notoriously
been a problematic area of research study for many years. The limiting selection of
transparent and robust materials in this wavelength region, together with the various
multilayer thin-film thickness constraints have prevented a suitable and sustainable
solution to many of these design issues. In this thesis, I describe the current
boundaries inherent to multilayer interference technology and investigate various
research alternatives to provide a tangible solution to these limitations.
Novel applications of improving the adhesion of infrared multilayers deposited on
CVD diamond optical substrates with amorphous hydrogenated diamond-like carbon
precursor films are investigated to assess their enhanced spectral and environmental
viability for use in future mid-infrared instruments.
An experimental research study into the intrinsic and composite stress properties of
deposited thick multilayers is presented with a view to understanding the optical and
mechanical effects resulting from bending deformations induced on optical substrates
by the deposited thin-film structures. Understanding and compensating for these stress
properties aided the construction of thin-film multilayers for focal plane detector array
filters on the Mars Climate Radiometer.
A research investigation into the application of novel short wavelength pass blocking
filters comprising metallic waveguide arrays manufactured by micro-machining
technologies is described. These enable enhanced mechanical properties that are
deficient in current filtering technology and contribute to spectral rejection of long