Suppression of photothermal convection using silicon carbide substrates for optofluidics experiments

Abstract

Photothermal convection on glass substrate has been a major obstacle for optofluidic measurement at elavated optical power. Here we demonstrate a strategy to suppress the photothermal convection by using silicon carbide substrates of high thermal conductivity for optimal heat sinking. We measure and compare the photothermal convection flow pattern and confirm that the photothermal convection on gold coated silicon carbide substrate is indeed much smaller than that on gold coated glass substrate. We further demonstrate the undisrupted optical acceleration using silicon carbon as optical window and stable plasmonic optical trapping. This technique is generally applicable to reduce photothermal heating and plasmonic optical tweezers based on patterned plasmonic nanostructures.