Hybrid sol-gel materials for integration of optoelectronic components

In this paper, we report on the integration of the Bragg filters with 1 × 8 multimode interference (MMI) power splitters on silicon substrate, and the demonstration of 1 × 8 external cavity distributed Bragg reflector (DBR) lasers. Hybrid organic-inorganic material is developed based on the sol-gel synthesis of an organically modified silicon alkoxide. The sol-gel material is spin coated on grated SiO₂/Si wafers, and the designed components (splitters and filters) are UV imprinted and developed using solvent assisted photolithography. The Bragg reflectors show filtering up to 98% with a bandwidth of about 0.8 nm consistent with their theoretical prediction. Integrated reflectors and MMI splitters are then used as feedback resonators for DBR lasers. Single-mode lasing with sidemode suppressions of up to 40 dB and a linewidth of about 400 kHz is observed. At 1550- nm wavelength, the loss and power uniformity in the MMI splitters, designed on the basis of lowest loss, are, respectively, 0.13 dB and 0.03 dB poorer than their theoretical calculations.