Applications of UV-nanoimprint soft stamps in fabrication of single-frequency diode lasers

We show how to use a modified poly-dimethyl-siloxane (PDMS) soft stamp to reduce pattern deformation and residual layer thickness in soft UV-nanoimprint lithography. A soft stamp thinned with toluene reduces the residual layer of a resist by as much as 50% compared to an unthinned stamp. We apply the soft UV-nanoimprint to prepare nanopatterned waveguides for a single-frequency diode laser. This laser operates with a side-mode suppression ratio of 50 dB, which indicates that the patterns are precise and uniform over the whole imprint field. To the best of our knowledge, this is the first single-frequency laser fabricated by soft UV-nanoimprint technology.