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