Loveraging on Agiltron's experience in optical fiber components, Agiltron proposed a coherent single-mode fiber (SMF) spatial filter array (SFA) with a gradient index fiber (GIF) lens array pair to meet NASA's application of planet exploration. There are several advantages over the current approach in: small aberration, low insertion loss, high uniformity, low cost, easy assembly and high stability. In Phase I, Agiltron will build a GIF-based SFA prototype to prove the feasibility of the proposed low cost program for NASA applications. At the same time, a theoretical study will be made to build a simulation model for the proposed SFA. This simulation and actual physical testing will provide the necessary baseline for us to build and demonstrate a prototype including the mechanical enclosures in Phase II. We expect to provide fully functional and environmentally tested production units for NASA in Phase II.