A fastener tab for securing absorbent garments is provided. Interference between spectral components generated by means of difference frequency generation and self phase modulation in one and the same non-linear crystal allows detecting and stabilizing the temporal evolution of the carrier-envelope offset phase. The request is received from the mobile device according to a wireless communications protocol. The collection portion of the assembly is attached to the cutting portion thereof. The exposure tool-offset can be adjusted on a wafer-to-wafer basis to correct for the derived overlay inaccuracy.