  We propose a method to design pulses in a resonant three-level system to
enhance the robustness of non-adiabatic geometric gate operations. By
optimizing the shape of the pulse envelope, we show that the gate operations
are more robust against frequency detuning than they are with Gaussian and
square pulses. Our method provides a way to design pulses that can be employed
in a system where robustness against frequency variations or inhomogeneous
broadening is required,and may be extended to ensure robustness against other
physical imperfections such as intensity fluctuations and random noises.
