A novel one step integration of edge-emitting laser diode withmicro-elliptical lens using focused ion beam direct deposition

摘要

An edge-emitting laser diode (LD) integrated with a microlens onnits emitting surface for the purpose of collimating and fiber couplingnis introduced in detail in this paper. A micro-elliptical lens isnadopted for the integration in terms of divergence angle in bothnparallel and transverse directions. The lens with dimensions of 50nΜm×30 Μm×4 Μm is microfabricated on the emittingnsurface of the laser diode with operating wavelength of 635 nm directlynby focused ion beam (FIB) deposition function. The SiO2ndeposition is realized by programming of the FIB machine. It is shown byntest results that the focused spot size in the parallel and transversenpropagation directions are 7.9 and 9.1 Μm (at site ofn1/e2), respectively, and the coupling efficiency of thencompact and miniaturized system can reach as high as 71%. Measurednfar-field angles (full angle) with the microlens in both parallel andntransverse directions are 2.2° and 1.2°, respectively. Comparednwith the original divergence angles of 31° and 14° without thenmicro-elliptical lens, they were greatly reduced by this method