Recent results on waveguide device fabrication by replication of inorganic-organic copolymers (ORMOCERs) are presented. The use of optimized ORMOCER resins offers advantages over conventional organic polymers. The organic as well as inorganic crosslinking is responsible to high thermal and chemical stability and thus an improved stability of the waveguide devices. Fluorination of ORMOCER side chains reduces the NIR absorption to < 0.4 dB/cm at 1.55 micrometers and < 0.3 dB/cm at 1.3 micrometers . Furthermore, the synthesis of purely inorganically crosslinked CH-free ORMOCER is possible. The refractive index can be tuned so that highly fluorinated core material can be combined with low-cost unfluorinated cladding material. The influence of the sidewall roughness of replication tools on scattering losses is investigated, and methods to fabricate smooth original structures have been developed leading to an additional scattering loss < 0.1 dB/cm in single-mode strip waveguides even at visible wavelengths. Furthermore, an improved deforming behavior is achieved. UV-patterning by UV-induced crosslinking is a second waveguide fabrication method used in ORMOCER. Applications of ORMOCERs in thermo- optical switching nodes are discussed.