  We consider light tunneling inhibition in periodic array of optical couplers
due to the specially designed longitudinal and transverse modulation of the
refractive index. We show that local out-of-phase longitudinal modulation of
refractive index in channels of directional couplers in combination with the
global refractive index modulation between adjacent couplers allow simultaneous
suppression of both local and global energy tunneling inside each coupler and
between adjacent couplers. This enables localization of light in single
waveguide despite the remarkable difference of corresponding local and global
energy tunneling rates.
