Project Title:
High efficiency diffractive optics at high numerical aperture
94-1 08.06 3010 A
High efficiency diffractive optics at high numerical aperture
Abstract:
Diffractive optics is finding an increased number of commercial and
military applications. They include spectrometry, imaging systems,
microlens arrays, optical interconnects, and high-power beam
samplers. For systems requiring diffractive optics of high
numerical apertures, it is crucial to investigate the properties of
these lenses using vector diffraction theory and not scalar
diffraction theory. By analyzing structures with vector diffraction
theory, the grating parameters such as depth and duty cycle can be
optimized in order to maximize diffraction efficiency. Note that
these grating parameters optimized through vector considerations do
not, in general, correspond to the grating parameters obtained
through a similar optimization routine utilizing scalar diffraction
theory. By using vector diffraction theory for the optimization of
high numerical aperture diffractive lenses, improved diffraction
efficiencies result. By improving the overall diffraction
efficiency of the element, one improves the signal-to-noise ratio
of the system as well as improving the MTF of the system by
reducing the amount of radiation scattered into extraneous
diffraction orders. These are important considerations for any
optical system, but in particular those designed for space-based
missions since diffractive optics offers these systems the
potential of weight and volume reduction without compromising
optical and mechanical specifications.
Commercial application areas that would benefit are numerous and
include any application utilizing high numerical aperture
diffractive lenses that have a speed of f/3 or greater. Compact
system for laser diode beam shaping, aft imagers in multispectral
systems and high resolution laser scan optics will benefit from the
research proposed herein.
Key Words
Rochester Photonics Corporation
330 Clay Road
Rochester, NY 14623