Ultrahigh Relative Refractive Index Contrast GaAs Nanowire Waveguides

An effective and practical fabrication procedure toward compound semiconductor nanowire waveguide on insulator is developed. GaAs nanowire waveguides with a cross-section of 400 × 400 nm 2 , bend radius of 10 µm, and a high relative refractive index contrast, Δ, of 40% were successfully fabricated for the first time. The propagation loss at 1.55 µm was measured to be approximately 4.5 dB/mm, and the bend loss was less than 0.8 dB per 90° bend. The losses were considered to be dominated by light scattering at the rough sidewalls.