Title

Optimal Design For Antireflective Tapered Two-Dimensional Subwavelength Grating Structures

Keywords

Antireflection; Diffractive optics; Effective-medium theory; Gradient index; Subwavelength gratings

Abstract

Techniques for the design of continuously tapered two-dimensional (2D) subwavelength surface-relief grating structures for broadband antireflection surfaces are investigated. It has been determined that the Klopfenstein taper [Proc. IRE 44, 31 (1956)] produces the optimum graded-index profile with the smallest depth for any specified minimum reflectance. A technique is developed to design the equivalent tapered subwavelength surface-relief grating structure by use of 2D effective-medium theory. An optimal Klopfenstein tapered 2D subwavelength grating is designed to reduce the Fresnel reflections by 20 dB over a broad band from an air-substrate (ns = 3.0) interface. The performance is verified by use of both a 2D effective- medium-theory simulation algorithm and rigorous coupled-wave analysis. These structures are also shown to achieve this low reflectance over a wide field of view (#fov > 110°). The pyramidal spatial profile, which has generally been assumed to produce the optimal broadband antireflection grating structure, is shown to require a significantly larger depth to achieve the same performance as a Klopfenstein-designed tapered antireflection grating structure. © 1995 Optical Society of America.

Publication Date

1-1-1995

Publication Title

Journal of the Optical Society of America A: Optics and Image Science, and Vision

Volume

12

Issue

2

Number of Pages

333-339

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1364/JOSAA.12.000333

Socpus ID

0029244349 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/0029244349

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