Open AccessSpatially graded TiO_2-SiO_2 Bragg reflector with rainbow-colored photonic band gap
Author(s) -
Dhruv Singh,
Seung Hee Lee,
Il Yong Choi,
Jong Kyu Kim
Publication year - 2015
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.23.017568
Subject(s) - optics , materials science , stack (abstract data type) , distributed bragg reflector , bragg's law , rainbow , photonic crystal , optoelectronics , photonics , substrate (aquarium) , reflection (computer programming) , wavelength , diffraction , physics , oceanography , computer science , programming language , geology
A simple single-step method to fabricate spatially graded TiO2-SiO2 Bragg stack with rainbow colored photonic band gap is presented. The gradation in thickness of the Bragg stack was accomplished with a modified glancing angle deposition (GLAD) technique with dynamic shadow enabled by a block attached to one edge of the rotating substrate. A linear gradation in thickness over a distance of about 17 mm resulted in a brilliant colorful rainbow pattern. Interestingly, the photonic band gap position can be changed across the whole visible wavelength range by linearly translating the graded Bragg stack over a large area substrate. The spatially graded Bragg stack may find potential applications in the tunable optical devices, such as optical filters, reflection gratings, and lasers.