Mode-division and spatial-division optical fiber sensors

Abstract

The aim of this paper is to provide a comprehensive review of mode-division and spatial-division optical fiber sensors, mainly encompassing interferometers and advanced fiber gratings. Compared with their single-mode counterparts, which have a very mature field with many highly successful commercial applications, multimodal configurations have developed more recently with advances in fiber device fabrication and novel mode control devices. Multimodal fiber sensors considerably widen the range of possible sensing modalities and provide opportunities for increased accuracy and performance in conventional fiber sensing applications. Recent progress in these areas is attested by sharp increases in the number of publications and a rise in technology readiness level. In this paper, we first review the fundamental operating principles of such multimodal optical fiber sensors. We then report on the theoretical formalism and simulation procedures that allow for the prediction of the spectral changes and sensing response of these sensors. Finally, we discuss some recent cutting-edge applications, mainly in the physical and (bio)chemical fields. This paper provides both a step-by-step guide relevant for non-specialists entering in the field and a comprehensive review of advanced techniques for more skilled practitioners.

Controlling light propagation in multimode fibers for imaging, spectroscopy, and beyond

“…Lastly, our selection of applications excludes the use of MMFs for telecommunications, especially spatial division multiplexing [1], as this material is already covered by numerous other sources [54][55][56][57]; moreover, many of the considerations explained here would not be scalable to the required dimensions (in terms of fiber lengths and environment stability). Multimode fiber sensors based on mode-and spatial-division have been reviewed recently [58], here we will not consider the MMF application for sensing environmental changes, instead we will focus on recovering the information of an input light from the output signals.…”

Flattening laser frequency comb spectra with a high dynamic range, broadband spectral shaper on-a-chip

“…Indeed, SiN fabrication via multi-project wafer runs (fabrication runs where customers pay for only a portion of a wafer), are now producing low loss (<0.5 dB/cm and 0.2 dB/cm more typically at 1550 nm propagation loss) waveguides and devices that are highly reproducible, which was ideal for rapid prototyping of concepts like this. Broadband functional photonics with these characteristics may also find application in biosensing, replacing or complimenting fibers, tapers and Bragg gratings [13][14][15].…”

Brillouin Interaction between Two Optical Modes Selectively Excited in Weakly Guiding Multimode Optical Fibers

“…With this device, broad-bandwidth ultrasound generation is achieved through the photoacoustic excitation of a special composite coating on the distal end of the multimode optical fiber by a pulsed laser [ 15 ]. Although most commercial sensing systems rely on measurements of the transmitted or reflected fundamental mode of single-mode optical fibers, more recent developments have focused on multimodal architectures that considerably widen the sensing modalities, especially in the chemical and biological fields [ 16 , 17 , 18 , 19 , 20 ]. Mode–division multiplexing is mooted to address the possibility of multiparameter sensing with a single device, the reduction of cross-sensitivities, and the improved accuracy of a single measured parameter by combining the responses of many fiber modes to its evolution.…”