  Pulsed high energy radiation from pulsars is not yet completely understood.
In this paper, we use the 3D self-consistent annular gap model to study light
curves for both young and millisecond pulsars observed by the Fermi Gamma-ray
Space Telescope. The annular gap can generate high energy emission for
short-period pulsars. The annular gap regions are so large that they have
enough electric potential drop to accelerate charged particles to produce
gamma-ray photons. For young pulsars, the emission region is from the neutron
star surface to about half of the light cylinder radius, and the peak
emissivity is in the vicinity of the null charge surface. The emission region
for the millisecond pulsars is located much lower than that of the young
pulsars. The higher energy gamma-ray emission comes from higher altitudes in
the magnetosphere. We present the simulated light curves for three young
pulsars (the Crab, the Vela, the Geminga) and three millisecond pulsars (PSR
J0030+0451, PSR J0218+4232, PSR J0437-3715) using the annular gap model. Our
simulations can reproduce the main properties of observed light curves.
