Distributed feedback ridge waveguide lasers fabricated by CNP process

Abstract

In this work, cost efficient hybrid polymer based Bragg grating ridge waveguide resonators were successfully fabricated by a cost-effective combined nanoimprint and photolithography process. By using this hybrid process, optical features with the size in the scale of nanometers (Bragg gratings) and micrometers (waveguides) could be defined simultaneously in one step. The high quality mask-stamp for the CNP process was fabricated by the combination of electron-beam lithography, reactive ion etching and standard lift-off methods on a UV transparent glass wafer. For the following CNP process, the silicon-containing, inorganic-organic hybrid material OrmoCore® was used as the ridge-type waveguide core material due to its high chemical and physical stability as well as its low optical loss in the visible wavelength region. After depositing the active gain material (Alq3:DCM2) on top of the duplicated Bragg grating area, an optically pumped distributed feedback ridge waveguide laser source has been successfully fabricated. The full width at half maximum value of the laser was 180pm and the threshold for laser activity at 652.34nm was about 19μJ/cm2.