A unique combination of attributes ideal for photonic technologies, is enjoyed by perfluorocyclobutyl (PFCB) polymers, such as manipulable refractive indices and thermo-optic coefficients, low transmission losses, high thermal, mechanical, and optical stability, and excellent processability. PFCB structures can be processed by direct micro-transfer molding (see Figure)-a step towards soft-lithographic fabrication of polymer lightwave circuits.