Title :
Far-Field and Near-Field Distribution of GaN-Based Photonic Crystal LEDs With Guided Mode Extraction
Author :
Lai, Chun-Feng ; Chi, Jim-Yong ; Kuo, Hao-Chung ; Yen, Hsi-Hsuan ; Lee, Chia-En ; Chao, Chia-Hsin ; Yeh, Wen-Yung ; Lu, Tien-Chang
Author_Institution :
Dept. of Photonics, Nat. Chiao Tung Univ. (NCTU), Hsinchu, Taiwan
Abstract :
The near-field and far-field distribution of GaN LEDs with square photonic crystal (PhC) lattice are experimentally investigated. The optical images of the near-field pattern are obtained from the guided electroluminescent light generated at the center of a special annular structure. For increasing lattice constant, symmetric patterns with varying number of petals according to the symmetry of the PhC are observed. The far-field distribution is studied with GaN-based film-transferred PhC LEDs with the thickness about 1500 nm. Angular-resolved measurements under electrical injection revealed guided modes extraction behavior and polarization based on the Bragg´s diffraction with the PhC lattice. Good agreement with the two-dimension free photon band structure is obtained.
Keywords :
III-V semiconductors; gallium compounds; light emitting diodes; photonic crystals; Bragg´s diffraction; GaN; GaN-based photonic crystal LEDs; guided mode extraction; near-field and far-field distribution; two-dimension free photon band structure; GaN; LEDs; photonic crystal (PhC);
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/JSTQE.2009.2015582
