KEYWORDS: Diffraction gratings, Multiplexing, Diffraction, Fiber Bragg gratings, Solar cells, Systems modeling, Solar energy, Data modeling, Holograms, Holography
Using diverse bandgap photovoltaic cells can improve solar conversion efficiency, but these systems also require efficient dispersive optics to direct portions of the solar spectrum onto the appropriate optimized cells. We use an extended coupled-mode model to show how multiplexed volume gratings interact with one another reducing efficiency in the diffraction orders of interest as well as increasing stray light under certain conditions. We conducted experiments with multiplexed gratings in dichromated gelatin to verify our theory. This technique reveals effects that cannot be seen through superposition of single grating models, which suggests that multiplexed gratings must be treated simultaneously when designing such a system.
Volume holographic elements can potentially combine many spectrally distinct laser beams using multiplexed Bragg
gratings. However, there are theoretical limits imposed by the interactions between these gratings. A method of
numerical simulation has been developed to analyze the interactions between many hundreds of multiplexed gratings in
a single volume holographic element. We apply this tool to the problem of spectral beam combining of incoherent laser
sources. Various system parameters limit the number of beams that can be combined under maximum bandwidth and
minimum efficiency constraints. System designs are shown that combine 180-350 lasers ranging over a 60nm bandwidth
with theoretical efficiencies in excess of 99%.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.