the present invention relates to an optical probe suitable for miniature applications . an example application is a fibre - based confocal miniaturized microscope . the optical probe comprises a coil - based actuation system comprising drive coils capable of displacing the distal end of an optical guide housed by the optical probe . the probe makes use of a feedback loop which alternate between driving the displacement of the optical guide by driving a current through the drive coils and switching off the current through the drive coils , and while the drive current being switched off , measure the speed of the distal end of the optical guide . the measured speed is compared to the set - point speed , and if a difference is detected , the drive current is adjusted to eliminate , or at least bring down , this difference .