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Distributed feedback(DFB)lasers based on holographic polymer dispersed liquid crystal(HPDLC)gratings have attracted much interest due to the advantages of low working threshold,high wavelength purity and a tunable range.As a result,these tiny lasers have great potential in working as optical sources for spectroscopy applications.However,the reported energy efficiency for DFB lasers based on HPDLC gratings is quite low around 0.3%until now.This poor energy efficiency restricts its application into devices.We analysed the reason should be from the poor quality resonators firstly because that the LC molecules aligned along the grating vector was found under a polarized microscope.It suggests that the difference of refractive index between LC and polymer layers is too small.Therefore we improve the forming process of the gratings,and have the efficiency increased from 0.3%to 0.9%.Secondly,the thin film of 2-methoxy-5-(2 ′-ethyl-hexyloxy)-p-phenylenevinylene(MEH-PPV)is used as gain medium instead of doping dye molecules and the HPDLC transmission grating is fabricated on the top of MEH-PPV layer.The result shows the energy efficiency as high as 6.5%.