Open AccessMonolithic integration of elliptic-symmetry diffractive optical element on silicon-based 45° micro-reflector
Author(s) -
Hsiao Chin Lan,
Hsu Liang Hsiao,
Chia Chi Chang,
Chih Hung Hsu,
Chin Ming Wang,
Mount-Learn Wu
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.020938
Subject(s) - optics , reflector (photography) , materials science , microsystem , etching (microfabrication) , silicon , wafer , optical fiber , optical axis , optoelectronics , coupling (piping) , focal length , physics , lens (geology) , light source , nanotechnology , layer (electronics) , metallurgy
A monolithically integrated micro-optical element consisting of a diffractive optical element (DOE) and a silicon-based 45 degrees micro-reflector is experimentally demonstrated to facilitate the optical alignment of non-coplanar fiber-to-fiber coupling. The slanted 45 degrees reflector with a depth of 216 microm is fabricated on a (100) silicon wafer by anisotropic wet etching. The DOE with a diameter of 174.2 microm and a focal length of 150 microm is formed by means of dry etching. Such a compact device is suitable for the optical micro-system to deflect the incident light by 90 degrees and to focus it on the image plane simultaneously. The measured light pattern with a spot size of 15 microm has a good agreement with the simulated result of the elliptic-symmetry DOE with an off-axis design for eliminating the strongly astigmatic aberration. The coupling efficiency is enhanced over 10-folds of the case without a DOE on the 45 degrees micro-reflector. This device would facilitate the optical alignment of non-coplanar light coupling and further miniaturize the volume of microsystem.