Prototyping of 6.2-mm-Pitch Fiber Positioner Modules for Stage-V Telescope Instrumentation

Small-pitch populated focal planes are a critical enabling technology for the next generation of highly multiplexed astronomical instruments. This work reports on ongoing prototyping activities for 6.2 mm-pitch alpha-beta (theta-phi) fiber positioner modules. Following a concise review of the underlying concept, the performance of trillium-based and independently actuated robotic designs is compared. Key operational parameters including XY positioning repeatability, non-linearity, backlash, and tilt are quantitatively assessed, with emphasis on their implications for overall instrument performance. Initial prototyping results are highly encouraging, indicating performance levels approaching the preliminary design specifications.