Loss-reduction of deeply etched InP/InGaAsP waveguides by CBE regrowth

Low-loss waveguides are the basic components in photonic integrated circuits (PICs). A high degree of integration can only be obtained by the use of small components. In general the size of optical components can be reduced by increasing the optical contrast. The maximum contrast in a ridge waveguide structure can be achieved by etching through all the waveguiding layers. Recently, it has been shown [1] that, the size of MMI-couplers and bends can be significantly reduced by the application of this deep etch technology. In addition, device performance of deeply etched waveguides is insensitive to etch depth variations.