University of Bath

Medical photonics

We use our research into cutting edge optical technologies to solve real-world clinical problems.

The end face of a multicore optical fibre
Multicore optical fibre is used for imaging inside the body

We design and fabricate optical fibres at our in-house fabrication facility to specifically address clinical needs. As part of the Proteus interdisciplinary research collaboration, we work closely with clinicians, engineers, other physical scientists, patient groups, industry and regulatory bodies from the outset to ensure our work makes a difference. We focus on endoscopic diagnosis and remote treatments which can be done through optical fibres to create miniature multifunctional devices which can easily fit into working channels of current clinical tools.

One example is the development of multicore fibres for endoscopic imaging. We have fabricated fibres with thousands of individual cores, each of which acts as a pixel in an image. Typically, light can hop between these cores as it travels along the fibre, seriously degrading image quality. We have overcome this in several ways, either allowing high performance imaging fibres to be fabricated from commonly available multimode preforms or producing superior imaging fibres in terms of resolution and wavelength range through glass-air fibre structures. Our work will lead to higher resolution imaging over a broad wavelength range and pave the way for economical disposable endoscopic tools.

Another example is the use of our hollow-core fibres to deliver light for remote sensing inside patients. Light can create vibrations in molecules, leaving a characteristic “fingerprint” on the spectrum that each molecule scatters. By collecting the scattered light, we can detect the signatures of specific molecules in a technique known as Raman spectroscopy. Trying to perform this technique through an optical fibre typically leads to a strong Raman signal from the glass in the core of the fibre swamping the weak signal from the target. We are investigating how our hollow-core fibres, where light propagates in air, enable this process to be carried out inside patients by minimising background from the fibre itself. Our hollow-core fibre probes require a single optical fibre and no additional optics to be placed on the tip entering the patient, allowing far smaller probes to reach locations deep inside the body.