Shaping the light transmission through a multimode optical fibre: complex transformation analysis and applications in biophotonics

Abstract

We present a powerful approach towards full understanding of laser light propagation through multimode optical fibres and control of the light at the fibre output. Transmission of light within a multimode fibre introduces randomization of laser beam amplitude, phase and polarization. We discuss the importance of each of these factors and introduce an experimental geometry allowing full analysis of the light transmission through the multimode fibre and subsequent beam-shaping using a single spatial light modulator. We show that using this approach one can generate an arbitrary output optical field within the accessible field of view and range of spatial frequencies given by fibre core diameter and numerical aperture, respectively, that contains over 80% of the total available power. We also show that this technology has applications in biophotonics. As an example, we demonstrate the manipulation of colloidal microparticles.

Controlling waves in space and time for imaging and focusing in complex media

“…Closely related to this study is the work of Cižmár and Dholakia (Fig. 5c), who achieved optical manipulation using a multimode fibre 114 .…”

Exploiting multimode waveguides for pure fibre based fluorescence imaging

“…15 A key illustrative example is the generation of optical vortices, that we create from a number of modes positioned along a circle of an adequate radius (with the radial index of p = 0) and gradually modify the phase of the sample modes accordingly to the required topological charge (integer number of 2π phase elevations along the circumference, see fig. 2 j).…”

“…Such procedure taking into account all the necessary aspects of the light field -phase, amplitude and polarisation was recently demonstrated and applied for the purpose of micromanipulation 15 and will be henceforth referred to as "the calibration".…”

Engineering light-matter interaction for emerging optical manipulation applications

“…Designed fibers can both modulate and deliver light [67]. Light modulation can be targeted in order to correct for aberrations in the light delivery [68] and the trapping environment [69]. The trapping environment can also be designed and tweaked to aid in optical micromanipulation.…”