In this paper, a load effect on a singlemode-multimode-singlemode (SMS) fiber structure embedded in a high-density
polyethylene (HDPE) was investigated numerically and experimentally. It was modelled that the applied load induces a
longitudinal strain on the HDPE and accordingly affects the SMS fiber structure’s parameters. It was calculated the
output power of the SMS fiber structure using a graded index multimode fiber (MMF) due to the applied strain from 0 to
4000 N. The experimental result shows that for the MMF length of 105 mm, the output power has monotonically
increasing for an applied load range from 1700 to 4000 N with a sensitivity of 1.18 x 10-3 dBm/N. This configuration of
SMS fiber structure embedded in the HDPE is potential for a load sensor.