All-in-fiber multiscan Mach-Zehnder interferometer assisted by core FBG for simultaneous multi-parameter sensing

et al. 2021

Sensors

In this invited review, we provide an overview of the recent advances in biomedical photonic sensors within the last five years. This review is focused on works using optical-fibre technology, employing diverse optical fibres, sensing techniques, and configurations applied in several medical fields. We identified technical innovations and advancements with increased implementations of optical-fibre sensors, multiparameter sensors, and control systems in real applications. Examples of outstanding optical-fibre sensor performances for physical and biochemical parameters are covered, including diverse sensing strategies and fibre-optical probes for integration into medical instruments such as catheters, needles, or endoscopes.

Section: Advances In Optical-fibre-based Biomedical Photonic Sensorsmentioning

confidence: 99%

Recent Advances in Biomedical Photonic Sensors: A Focus on Optical-Fibre-Based Sensing

Ochoa

Algorri

et al. 2021

Sensors

“…In this way, the cross-section can be controlled by the number of scans performed. In addition, this method modifies the refractive index change with each scan up to a limit, which allows increased control over waveguide properties [122,124]. This technique has been employed to manufacture remarkably complex sensors [112].…”

Section: Waveguide Typesmentioning

confidence: 99%

“…This cross-sensitivity can be easily fixed by another sensing element inscribed in the interferometer. There are works reporting an FBG inscribed in both CWG [112] and core [122] of the MZI, increasing its sensing potential.…”

Section: Some Applicationsmentioning

confidence: 99%

See 1 more Smart Citation

Optical Fiber Sensors by Direct Laser Processing: A Review

Pallarés-Aldeiturriaga

Rodŕıguez-Cobo

et al. 2020

Sensors

The consolidation of laser micro/nano processing technologies has led to a continuous increase in the complexity of optical fiber sensors. This new avenue offers novel possibilities for advanced sensing in a wide set of application sectors and, especially in the industrial and medical fields. In this review, the most important transducing structures carried out by laser processing in optical fiber are shown. The work covers different types of fiber Bragg gratings with an emphasis in the direct-write technique and their most interesting inscription configurations. Along with gratings, cladding waveguide structures in optical fibers have reached notable importance in the development of new optical fiber transducers. That is why a detailed study is made of the different laser inscription configurations that can be adopted, as well as their current applications. Microcavities manufactured in optical fibers can be used as both optical transducer and hybrid structure to reach advanced soft-matter optical sensing approaches based on optofluidic concepts. These in-fiber cavities manufactured by femtosecond laser irradiation followed by chemical etching are promising tools for biophotonic devices. Finally, the enhanced Rayleigh backscattering fibers by femtosecond laser dots inscription are also discussed, as a consequence of the new sensing possibilities they enable.

“…Typically there are two options for sensing fluids located around the fiber: by guiding the light to the cladding 6 , 7 (or by modifying the geometry of the fiber 8 , 9 ), or by entering the fluid inside the fiber 1 , 3 , 10 , 11 . The latter notably improves sensitivity, and has been achieved through the manufacture of microchannels or microfluidic reservoirs 1 .…”

mentioning

confidence: 99%

Liquid level sensor based on dynamic Fabry–Perot interferometers in processed capillary fiber

Pérez-Herrera

Rodŕıguez-Cobo

et al. 2021

Sci Rep

In this work, a novel optical fiber sensor capable of measuring both the liquid level and its refractive index is designed, manufactured and demonstrated through simulations and experimentally. For this, a silica capillary hollow-core fiber is used. The fiber, with a sensing length of 1.55 mm, has been processed with a femtosecond laser, so that it incorporates four holes in its structure. In this way, the liquid enters the air core, and it is possible to perform the sensing through the Fabry–Perot cavities that the liquid generates. The detection mode is in reflection. With a resolution of 4 μm (liquid level), it is in the state of the art of this type of sensor. The system is designed so that in the future it will be capable of measuring the level of immiscible liquids, that is, liquids that form stratified layers. It can be useful to determine the presence of impurities in tanks.