Interest in silica flat fibre-based sensing technology has been fuelled by their flexibility, defined orientation, and ease of integration with fibre composites, in particular for structural health monitoring. However, the solid flat fibre strain sensitivity remains largely dictated by bulk material properties. We demonstrate here the fabrication and use of a silica microstructured flat fibre with a dual hole cross section for pressure sensing, wherein two sealed air holes concentrate strain caused by external pressure changes to a central glass region containing a waveguide core and Bragg gratings, thus enhancing their sensitivity. Integrated sensing elements were inscribed by femtosecond laser λ = 515 nm 200 fs pulses in the central region, including a waveguide and two identical 4th order 3 mm long gratings at λ = 1.55 μm Bragg wavelength separated by 11 mm to form an interference sensor. The laser inscription provides an intrinsic waveguide birefringence leading to a Vernier effect in the reflected spectrum. When external pressure is increased, the birefringence changes resulting in sensitive peak and dip level changes. The sensor was interrogated using a broadband erbium doped amplifier source while recording the back-reflected spectrum as pressure was varied from 0 to 5 bar using a nitrogen pressure chamber enclosing the sensor. The peak-to-dip extinction showed a linear pressure sensitivity of 0.83 dB/bar over the 0 to 3 bar range, before plateauing at 4 bar and decreasing slightly at 5 bar, as well as a high consistency under repeated pressure ramping.

A lab-in-a-fiber component was fabricated using an optical fiber and a fiber capillary. It was used in a test suspension of fluorescently labeled and unlabeled cells and enabled detection of the labeled cells. Subsequently the labeled cells were selectively collected via suction into the capillary. A novel sampling technique reduced photobleaching of the labeled cells, extending the measurement time. The collected cells remained viable for downstream analysis. This platform’s low fabrication cost, simplicity, compatibility with standard laboratory equipment, and capacity for fully automated cell capture highlights its potential for future applications in minimally invasive sample collection and point-of-care diagnostics. We demonstrate this LiF device to showcase the capability of optical fiber technology in creating low-cost, low-complexity cancer diagnostic devices. Furthermore, the LiF device holds promise for in vivo diagnostics, facilitating cell isolation and analysis.

The current landscape of optical fiber technology is dominated by fibers with a circular cross-section with axial symmetry and a centrally positioned waveguiding core. This typical layout is dictated by traditional manufacturing routes that often utilize furnaces, gas burners, and glass lathes. Contrastingly, in our work, we utilize laser-based glass additive-manufacturing to melt, weld, and reshape glass powders and prefabricates to create fiber preforms. Additionally, through a combination of mid-IR CO2 laser melting and oxide nano-powder jets aimed into laser-induced hot-zone, high quality glass features can be 3D-printed onto the fiber preform. In our work we focus on high-aspect ratio preforms that can be then drawn in traditional draw towers into over 100 m long ultra-thin fibers. Here, flat fibers as thin as 35 µm and aspect-ratio of up to 27:1 with sub-µm surface flatness were made. Furthermore, by utilizing this novel print-stack-draw approach, microstructure and chemically doped features for e.g., waveguiding and optical gain can be spatially tailored, both laterally and along the direction of draw. Compatibility of these fibers with standard counterparts such as commercial single-mode-fibers was demonstrated through e.g., laser-based splicing. The new manufacturing approach utilized in this work unlocks highly flexible, novel photonic designs with large disruptive potential for areas including lab-in-fiber, physical sensors and fiber lasers.

Growing numbers of uncrewed aerial vehicles (UAVs) in delivery, surveillance, and military applications are driving the need for automated flight inspections. Traditional inspections are done by ground maintenance crew, which limits total number of operational drones. Here we propose a condition monitoring solution combining optical fibre Bragg gratings (FBGs) with a newly developed scattering interrogation system. Our demonstration shows system stability and effective monitoring of strains incurred on the UAV wings during flight.

As demand for customized specialty fibers grows, standardized production methods face challenges. This article reviews industry standards and discusses potentially disruptive techniques that enable rapid prototyping and fabrication of optical fiber devices. Furthermore, we showcase laser powder deposition's (LPD) potential for additive manufacturing (AM) of customized glass structures. In the case of, for example, fiber preforms, although the feasible size is smaller than the industry standard, utilizing laser-based manufacturing techniques for a small batch production presents an attractive avenue for rapid prototyping and expedites material and design optimization. In the realm of AM of glass, LPD offers numerous benefits, including minimal shrinkage, high densification, and the ability to tailor glass composition to achieve desired optical properties. The article reviews the latest achievements and highlights future directions in this technology.

In this study, quenching dynamics in RE-doped silica glass were investigated through the measurement of excited-state lifetimes of heavily doped silica micro-hemispheres fabricated directly on the end face of a multimode fiber (MMF).

We present an optical fiber-based selective cell picking module capable of picking up and transferring single cells or clusters. Our Lab-in-a-fiber (LIF) module detects labelled cancer cells (MCF-7) and picks them up for further analysis.

We present an optical fiber-based selective cell picking module capable of picking up and transferring single cells or clusters. Our Lab-in-a-fiber (LIF) module detects labelled cancer cells (MCF-7) and picks them up for further analysis.

We present an optical fiber-based selective cell picking module capable of picking up and transferring single cells or clusters. Our Lab-in-a-fiber (LIF) module detects labelled cancer cells (MCF-7) and picks them up for further analysis.

Novel approaches for laser-based silica processing are demonstrated, that offer unique fabrication capabilities for specialty fibers. High performance and new fiber geometries are offered through multi-material additive manufacturing, cutting, polishing, welding and laser-based preform drawing.