Ultra-precision stylus measurement of micro V-groove array for optical fiber location

Micro V-groove array is a critical fundamental component of optical fiber array for optical communication system of next generation. The accuracy of micro V-groove directly determines the precision of optical fiber array. The test precision of the image method and the light intensity search method can't satisfy the test requirements including micro V-groove pitch and depth currently. A new stylus measurement method is presented for the ultra-precision testing of micro V-groove array. Stylus profilometer is used to travel over the surface of micro V-groove, the measurement data points are fitted by cubic spline curve. The center of optical fiber circle in the V-groove is calculated according to the theory of equidistant line. The least square theory is used to qualify the error of core pitch and depth combined with theoretical analysis of measurement accuracy in the error theory. The impact of deviation error in the workpiece clamping is analyzed, and a differential method is presented to eliminate the deviation error. The experimental result indicates that the new measurement method can accurately detect the precision of micro V-groove array.