Light Guide Plate with Sub-micron Gratings

A light guide plate(LGP)based on sub-micron gratings(SMGs)is proposed and its initial structure is given.The periods of SMGs are 0.651 μm,0.516 μm and 0.433 μm for the LED light sources transmit out vertically with the incidence angle 45° under the total internal reflection condition.The transmission efficiencies vary at 2~43% when the depth of grooves of SMGs changes at 0.05~0.9 μm by using rigorous coupled-wave theory(RCWT).The results show that the LGP utilizing the characteristics of the SMGs can control the transmission angle and get homogeneous output.The transmission angle is calculated with incidence angle under given range.