Single-mode low-loss buried optical waveguide bends in GaInAsP/InP fabricated by dry etching

Low-loss single-mode buried optical waveguide bends in MOVPE-grown InP-based materials are reported. Reactive ion etching (RIE) was used to fabricate the curves which were subsequently buried in InP to reduce optical losses and to control the number of lateral guided modes. Losses as low as 1.1 dB for 200 mu m radius of curvature and 0.3 dB for 300 mu m radius of curvature have been measured using TE-polarised light at 1.553 mu m wavelength.