We have found an error in our work reported in [1] which we correct in this erratum. We used incorrect data for the experimentally measured values of power of the fibre trap, and power of the conventional optical tweezers (OT) used to ‘break’ the fibre trap. Using the correct data for power of the fibre and conventional OT, F_fibre and Q (force and quality) of the multicore fibre tweezer are re-calculated.

In section 3.2- MCF-based tweezer characterisation, we report incorrect values for fibre trap powers and conventional optical tweezer (OT) powers. Our original paper stated “The instant that the fiber trap is broken by the OT, F_fibre is equal to F_trap. This is performed for fiber-trap powers between 6- 30 mW and is repeated for 4-5 times for different cells for each power. OT powers in the range of 0.2 mW to 0.4 mW were sufficient to break the fiber trap.

We correct this here to state: The instant that the fiber trap is broken by the OT, F_fiber is equal to F_trap. This is performed for fiber-trap powers between 19-30 mW and is repeated for 4-5 times for different cells for each power. OT powers in the range of 1 mW to 4 mW were sufficient to break the fiber trap.”

A revised Fig. 7 showing the corrected calculated values of F_fibre and Q is shown below.

 

Fig. 7. Blue triangles: Experimental values of the fiber force (F_fiber) which were calculated by equating the trapping force of the OT (F_trap) that broke the fiber trap. Orange circles: The efficiency factor Q for different total powers of the tweezing probe.

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The caption for Fig. 7 caption remains unchanged.

A statement in the abstract and in the conclusions must be corrected. In the original manuscript, we incorrectly state in the abstract: “A stable trap with a maximum total power 30 mW has been characterized to exert a maximum optical force of 26.4 pN, on a trapped, 7 µm diameter yeast cell.” This should read: A stable trap with a maximum total power 30 mW has been characterized to exert a maximum optical force of 1.8 pN, on a trapped, 7 µm diameter yeast cell.

In the original manuscript we incorrectly state in Section 4- Conclusions, “The MCF-based tweezer has a maximum NA of 1.039, for 67.5° mirror angle, and can exert a maximum trapping force of 26.5 pN, as measured using well-characterized, orthogonally directed, conventional optical tweezers. Finally, the quality, Q of this particular fiber trap was calculated to be between 0.067 and 0.198, in line with conventional optical tweezers, but allowing more flexibility in the type of trapping and imaging experiments that can be performed.”

Since the maximum force applied is actually 1.8 pN, not 26 pN, and since the Q factor is calculated to be between 0.0087-0.0136 (average 0.010), not 0.067-0.198, our revised conclusion is therefore: The MCF-based tweezer has a maximum NA of 1.039, for 67.5° mirror angle, and can exert a maximum trapping force of 1.8 pN, as measured using well-characterized, orthogonally directed, conventional optical tweezers. Finally, the quality, Q of this particular fiber trap was calculated on average to be 0.010, less efficient than conventional optical tweezers, but allowing more flexibility in the type of trapping and imaging experiments that can be performed.