Investigation of single mode fiber coupling using diffractive optical element with continuous relief fabricated by focused ion beam technology

The design, microfabrication and testing of diffractive optical elements (DOE's) with continuous relief and their use in fiber coupling, is discussed in detail. DOE's with diameter as small as 65 /spl mu/m are realized by means of focused ion beam (FIB) technology. A focused Ga/sup +/ ion beam is used to mill a continuous relief microstructure at an acceleration voltage of 50 kV. From the results of the test, a coupling efficiency of 75% was achieved. This indicates that the DOE's were suitably designed within the application requirements and satisfactorily manufactured by using FIB.