Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/43371

Title

Direct femtosecond fabrication in high refractive index materials

Author(s)

Zhou, Guangyong;  Gu, Min

Abstract

Photonic crystals (PhCs) are believed to be the basic platform for many advanced applications such as ultrasensitive optical sensing devices, ultra-low threshold lasers and ultra-fast data processing and telecommunications. To realize these cutting-edge devices, the PhCs need to have 3D complete bandgap. In other words, the PhCs needs to be fabricated in high refractive index materials. Another very important feature is that the materials need to have large nonlinearity to realize functional devices. Lithium niobate (LiNbO3) and chalcogenide glasses (ChGs) are excellent candidates which can meet both criteria. LiNbO3 has a high refractive index of ∼2.2 and a large transparent range of 0.45-5 μm which makes it a suitable candidate for near-infrared photonic crystal fabrication. ChGs are amorphous materials containing one of the chalcogen elements (e.g., S, Se, Te) and a wide array of other elements (e.g., As, Ge, Cd, etc). This class of glasses have high refractive index (>2.4) and excellent transparency in the infrared wavelength region (1 μm-15 μm). The direct laser writing technique has been proved to be an efficient method to fabricate PhCs in low refractive index materials [1-3]. However, in high refractive materials the refractive index mismatch between materials and immersion medium introduces very strong aberration distorts the focus region [4]. Although previous results show that 3D PhCs can be fabricated directly in LiNbO3 by using the femtosecond laser induced microexplosion method [5, 6] and in As2S3 by using the two photonic polymerization method [7], strong aberration still cause serious distortion at the focus region and therefore deteriorate the quality of the PhCs. Here we will review the problems of direct laser writing in high refractive index materials and aberration compensation using the adaptive optics method.

Publication type

Conference paper

Research centre

Swinburne University of Technology. Faculty of Engineering and Industrial Sciences. Centre for Micro-Photonics

Source

Proceedings of the Progress In Electromagnetics Research Symposium, PIERS 2008, Hangzhou, China, 24-28 March 2008

Publication year

2008

Keyword(s)

Femtosecond fabrication;  PhCs;  Photonic crystals

Publisher

The Electromagnetics Academy

Publisher URL

http://piers.mit.edu/piers/