We report some recent progresses made in Shandong University on improving the light emission efficiency(LEE)of both GaN and AlGaInP light emitting diodes(LEDs).We first show the microstructural aspects of both LEDs.Then,we show some new techniques developed on fabricating novel optical radiation patterns(ORPs)on LEDs.These techniques include 1)porous ORPs fabricated by plasmonic catalysis,2)ITO nanorods fabricated on GaN LEDs by e-beam evaporation,2)roughened p-GaN by direct pulsed UV laser writing,3)composite ZnO ORPs composed of both microscale and nanoscale substructures,and 4)pyramidal patterns on AlGaInP LEDs by laser induced photochemical etchings.All these techniques can be readily transferred to existing manufacturing line.The underlying principles for these fabrication methods are discussed in details.The effects of the ORPs on light extraction are evaluated by both photoluminescent(PL)spectroscopy and angel-resolved electroluminescent(EL)spectroscopy.Possible damages to electrical conductivity by the microfabrication methods are also discussed.We conclude that crystallographic feature,surface aspects,the band structure at semiconductor/environment interface and its local variation due to the presence of defects,either intrinsic or extrinsic,need to be carefully considered during fabrication of light extraction patterns on LEDs.