Open AccessHigh efficiency geometric-phase polarization fan-out grating on silicon
Author(s) -
Chenhao Wan,
David Lombardo,
Andrew Sarangan,
Qiwen Zhan
Publication year - 2017
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.024559
Subject(s) - grating , optics , materials science , electron beam lithography , diffraction efficiency , blazed grating , fabrication , lithography , diffraction grating , polarization (electrochemistry) , interference lithography , electromagnetically induced grating , optoelectronics , resist , physics , nanotechnology , medicine , chemistry , alternative medicine , layer (electronics) , pathology
We report the design, fabrication and characterization of a 1-by-5 geometric-phase polarization fan-out grating for coherent beam combining at 1550 nm. The phase profile of the grating is accurately controlled by the local orientation of the binary subwavelength structure instead of the etching depth and profile empowering the grating to be more tolerant to fabrication errors. Deep-UV interference lithography on silicon offers an inexpensive, highly efficient and high damage threshold solution to fabricating large-area fan-out gratings than electron beam lithography (EBL) and photoalignment liquid crystals. The theoretical and experimental diffraction efficiency of the grating is 87% and 85.7% respectively. Such a fan-out grating may find application to high-power beam combining in the infrared regime.