Characterization of random anti-reflecting surface structures and their polarization response at off-normal angles of incidence

Gopal Sapkota; Jason R. Case; Lynda E. Busse; Jesse A. Frantz; L. Brandon Shaw; Jasbinder S. Sanghera; Ishwar D. Aggarwal; Menelaos K. Poutous

doi:10.1117/12.2235380

15 September 2016 Characterization of random anti-reflecting surface structures and their polarization response at off-normal angles of incidence

Gopal Sapkota, Jason R. Case, Lynda E. Busse, Jesse A. Frantz, L. Brandon Shaw, Jasbinder S. Sanghera, Ishwar D. Aggarwal, Menelaos K. Poutous

Author Affiliations +

Proceedings Volume 9927, Nanoengineering: Fabrication, Properties, Optics, and Devices XIII; 992712 (2016) https://doi.org/10.1117/12.2235380
Event: SPIE Nanoscience + Engineering, 2016, San Diego, California, United States

Abstract

Random anti-reflecting surface structures (rARSS) are fabricated on fused silica substrates, for broadband and omnidirectional applications. These structures are fabricated using dry reactive ion etching. Etching parameters, such as RF power, flow ratio of etching gases, and etching time, determine the surface morphology of the random structures. The surface roughness of the random structures induces a gradient index transition over the boundary, yielding transmission enhancement compared to plain polished fused silica. We present variable angle-of-incidence (AOI) and polarization transmission measurements, through rARSS on fused silica at 633nm, and compare the results with conventional AR coating simulations. We tested a number of different samples, all with optimized transmission near 633nm, but different surface characteristics, and found that rARSS have structural characteristics which affect transmission at non-normal angles of incidence. We show that rARSS on fused silica substrates outperform conventional BBAR and SLAR thin film coatings in transmission enhancement, for incident light with AOI from 0° to 55°. We measured rARSS with zero degree of polarization in transmission, for AOI ranging from 0° to 60° in certain cases. A figure of merit that includes both the transmission degree of polarization and transmission enhancement is formulated in order to quantify rARSS performance for both effects. We found that rARSS measured performance is better than SLAR and BBAR, for transmission with AOI greater than 30° and up to 70°, especially for p-polarized incident light, which is the stricter criterion. Applications requiring polarization insensitivity and AR performance can be positively impacted by these surface structures.

Conference Presentation

Citation Download Citation

Gopal Sapkota, Jason R. Case, Lynda E. Busse, Jesse A. Frantz, L. Brandon Shaw, Jasbinder S. Sanghera, Ishwar D. Aggarwal, and Menelaos K. Poutous "Characterization of random anti-reflecting surface structures and their polarization response at off-normal angles of incidence", Proc. SPIE 9927, Nanoengineering: Fabrication, Properties, Optics, and Devices XIII, 992712 (15 September 2016); https://doi.org/10.1117/12.2235380

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

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.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available