Laser　induced　backside　dry　etching　(LIBDE)　is　a　novel　technique,　which　applied　in　the　micromachining　and　nanomachining　of　transparent　dielectric　materials　used　for　optical　elements　by　direct　laser　irradiation　with　the　assistance　of　solid　mediums　as　an　absorbed　layer.　On　the　basis　of　exploring　two　different　solid　mediums,　i.e.　Al2O3　powder　and　alumina　ceramic　wafer　as　absorbers,　LIBDE　with　1064　nm　central　wavelength　pulsed　ytterbium　doped　fiber　laser　as　the　irradiation　source　was　successfully　applied　for　the　fabrication　of　periodical　microscaled　structures　on　fused　silica.　The　threshold　of　laser　fluence　to　etch　fused　silica　was　7.47　J/cm(2)　extrapolated　from　the　experimental　data.　By　using　alumina　ceramic　wafer　as　the　absorber,　a　microbinary　dimensional　transmittance　grating　with　the　constant　of　25　mu　m　was　obtained　on　the　silica.　The　depth　of　the　trench　is　4.2　mu　m,　and　the　root　mean　square　roughness　of　the　trench　bottom　is　below　40　nm　according　to　the　measurement　of　3D　profiler.　Additionally,　diffraction　patterns　were　observed　by　the　normal　incidence　of　a　532　nm　diode　indicator　laser　to　examine　the　optical　features　of　the　microbinary　grating　etched　under　the　different　laser　fluences.　(C)　2012　Laser　Institute　of　America.