This work presents a novel interferometric structure based on two single-mode fibers twisted and fused in a helical structure through a commercial CO2 laser processing station. The resulting device induced macrobending effects that promote light coupling from the core to the cladding and vice versa, creating an interferometric pattern in the transmission spectrum due to the phase difference between the light travelling in the core and cladding regions. The influence of the twist period on the spectral response showed an increased attenuation and higher fringe contrast for shorter twist periods, i.e., low bending radius. The sensing capabilities of the structure were evaluated for torsion, strain, and temperature, yielding sensitivities of − 0.49 nm/(rad/m), –8.8 pm/με, and –81 pm/ ◦C, respectively. Temperature cross-sensitivity was also evaluated, showing values of 0.17 (rad/m)/ ◦C for torsion and 9 με/ ◦C for strain. These results highlight the potential of the structure for torsion sensitivity with high sensitivity and low cross- ensitivity. Therefore, this work demonstrates as well that these parameters can be measured using conventional single-mode fiber structures instead of complex and more expensive optical fibers, thereby reducing both cost and system complexity through a simpler and automated fabrication process compared with other fiber-optic sensors.