Progress in the domain of complex photonics enabled a new generation of minimally invasive, high-resolution endoscopes by substitution of the Fourier-based image relays with a holographic control of light propagating through apparently randomizing multimode optical waveguides. This form of endo-microscopy became recently a very attractive way to provide minimally invasive insight into hard-to-access locations within living objects.
Here, we review our fundamental and technological progression in this domain and introduce several applications of this concept in bio-medically relevant environments.
By taking advantage of the cylindrical symmetry of the fibre and the known distribution of the refractive index, we show how to simplify measurement of the transmission matrix of such fibres and correct for the influences of bending deformations.
Our newest addition is the employment of Graded-index fibres, which, based on our numerical model, and first experimental verifications, allow for much simpler compensation of bending deformation when compared to step-index fibres.
Lastly we show the development and exploitation of highly specialized fiber probes for optical manipulation. We show that light control through these fibres allows sufficiently tight focusing for confinement and manipulation of large particle arrays, and their positioning with nanometric precision.
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