III-Nitride-based planar lightwave circuits for long wavelength optical communications

Rongqing Hui, Yueting Wan, Jing Li, Sixuan Jin, Jingyu Lin, Hongxing Jiang

Research output: Contribution to journalArticle

42 Scopus citations

Abstract

Planar lightwave circuits based on III-nitride wide-bandgap semiconductors are proposed and the feasibility of developing III-nitride-based novel photonic integrated circuits for applications in fiber-optical communications is discussed. III-nitrides have low attenuation in the near-infrared wavelength region because of their wide bandgaps, while as semiconductors their refractive indexes can be modulated by carrier injection. III-nitrides are also well known for their ability to operate at high temperatures, high power levels and in harsh environments. These characteristics make III-nitrides ideal candidates for tunable optical phased-array (PHASAR) devices for optical communications. We have characterized the optical properties of Al x Ga1-x N epilayers in the 1550-nm wavelength region, including the refractive indexes and the impact of Al concentrations. Single-mode ridged optical waveguide devices using GaN-AlGaN heterostructures have been designed, fabricated and characterized for operation in the 1550-nm wave-length window. The birefringence of wurtzite GaN grown on sapphire substrate has been observed. Refractive indexes were found to be different for signal optical field perpendicular and parallel to the crystal c axis (n⊥ ≠ n//). More importantly, we found an approximately 10% change in the index difference Δn = n// - n⊥ with varying the waveguide orientation within the c plane, and a 60 ° periodicity was clearly observed. This is attributed to the hexagonal structure of the nitride materials. Various functional waveguide devices have been realized, including 2 × 2 directional couplers and eight-wavelength array-waveguide gratings. Theoretical predictions of temperature sensitivity and the efficiency of carrier-induced refractive change are provided.

Original languageEnglish
Pages (from-to)100-110
Number of pages11
JournalIEEE Journal of Quantum Electronics
Volume41
Issue number1
DOIs
StatePublished - Jan 2005

Keywords

  • Integrated optics
  • Optical communication
  • Planar waveguides
  • Semiconductor devices
  • Semiconductor materials
  • Semiconductor waveguides
  • Wavelength division multiplexing

Fingerprint Dive into the research topics of 'III-Nitride-based planar lightwave circuits for long wavelength optical communications'. Together they form a unique fingerprint.

  • Cite this