Gold-ruby glass in a new light: On the microstructuring of optical glasses with synchrotron radiation

We describe the microstructuring of gold-ruby glasses with synchrotron radiation. Plasmonic or luminescent microstructures with a lateral width of minimum 5 μm can be written directly into the glasses by implementing X-ray lithography. The technique involves two steps: First, gold containing glass samples are irradiated with synchrotron X-rays through a microstructured mask. And second, subsequent annealing at minimum 500°C induces the growth of gold nanoparticles. The patterned sites are ruby coloured due to the gold surface plasmon resonance of gold nanoparticles. Furthermore we investigated the photoluminescence of the microstructured glass. After synchrotron irradiation a red photoluminescence is observed under UV light excitation. Subsequent annealing for a few minutes at 300°C induces the quenching of the red luminescence. If the irradiated sample is annealed for 5 minutes at a higher temperature of 500°C a bright green light emission is detected. The green photoluminescence decreases after further annealing and finally vanishes. We assume that the origin of the luminescence are silicate hole centres. The technique of generating gold particles with synchrotron X-ray lithography has potential to produce micro-optical devices like optical storage units, photonic crystals, gratings or sensors.