Triangular electrode steers soliton beam in slab waveguide
A group of researchers from the University of Central Florida Center for Research and Education in Optics and Lasers (CREOL) and the University of Glasgow (Glasgow, Scotland) has, by imprinting a triangular electrode onto an aluminum gallium arsenide slab waveguide, created an electronically controllable prism that can angularly steer a spatial soliton within the waveguide. Current injected by the electrode into the waveguide lowers its refractive index over the area of the electrode, causing simple refraction at the boundaries of the triangle. Because a spatial soliton is essentially a one-dimensional waveguide formed by nonlinear optical effects, a separate signal beam can be sent through the soliton; as a result, wherever the soliton is steered, the signal follows. The device has potential as an electronically addressable 1 x N interconnect.
Light from a modelocked color-center laser emitting at 1.55 µm was used to create a TE-polarized soliton and a TM-polarized signal, separable for analysis. Prisms of varying angles were tested, with the smallest angle of 0.3 causing the largest deflection. Beam displacement at the output face of the waveguide was as much as 30 µm, or about one full width at half maximum of the soliton beam.