Three-dimensional control of light in a two-dimensional photonic crystal slab

Journal Article · Tue Feb 15 04:00:00 EST 2000 · Nature

DOI:https://doi.org/10.1038/35001602· OSTI ID:751252

CHOW, KAI-CHEUNG ^[1]; LIN, SHAWN-YU; JOHNSON, S G; VILLENEUVE, P R; JOANNOPOULOS, J D; WENDT, JOEL R; VAWTER, GREGORY A; ZUBRZYCKI, WALTER J; HOU, HONG Q; ALLERMAN, ANDREW A

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1. Sandia National Laboratories

A two-dimensional (2D) photonic crystal is an attractive alternative and complimentary to its 3D counterpart, due to fabrication simplicity. A 2D crystal, however, confines light only in the 2D plane, but not in the third direction, the z-direction. Earlier experiments show that such a 2D system can exist, providing that the boundary effect in z-direction is negligible and that light is collimated in the 2D plane. Nonetheless, the usefulness of such 2D crystals is limited because they are incapable of guiding light in z-direction, which leads to diffraction loss. This drawback presents a major obstacle for realizing low-loss 2D crystal waveguides, bends and thresholdless lasers. A recent theoretical calculation, though, suggests a novel way to eliminate such a loss with a 2D photonic crystal slab. The concept of a lightcone is introduced as a criterion for fully guiding and controlling light. Although the leaky modes of a crystal slab have been studied, there have until now no experimental reports on probing its guided modes and band gaps. In this paper, a waveguide-coupled 2D photonic crystal slab is successfully fabricated from a GaAs/Al{sub x}O{sub y} material system and its intrinsic transmission properties are studied. The crystal slab is shown to have a strong 2D band gap at {lambda} {approximately} 1.5 {micro}m. Light attenuates as much as {approximately}5dB per period in the gap, the strongest ever reported for any 2D photonic crystal in optical {lambda}. More importantly, for the first time, the crystal slab is shown to be capable of controlling light fully in all three-dimensions. The lightcone criterion is also experimentally confirmed.

• Research Organization: Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 751252
• Report Number(s): SAND2000-0431J
• Journal Information: Nature, Journal Name: Nature
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
ALUMINIUM OXIDES
CRYSTALS
ENERGY GAP
GALLIUM ARSENIDES
LIGHT TRANSMISSION
SEMICONDUCTOR LASERS
WAVEGUIDES