Asymmetric optical multimode splitters by field-assisted ion exchange using patterned mask openings

Asymmetric optical multimode splitters based on optical waveguides were fabricated in glass substrates using a field-assisted ion exchange process. Accompanying simulations, conducted to study the light propagation, revealed the possibility to realize asymmetric splitters based on waveguides with different width. In the exchange process, broad mask openings in the blocking layer are compared to those consisting of closely spaced parallel lines with various widths. The waveguide profiles of the resulting splitters were recorded and the optical losses and splitting ratios were determined for a wavelength of 850 nm. Additionally data transmission tests were conducted and showed the suitability of the splitters for a bandwidth of 28 GBit/s.