Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
Real-time dynamic strain measurements under a high temperature environment is important for many applications, e.g. component fault diagnosis of aeroengines. The sapphire fiber is an ideal device for extreme sensing due to its high melting temperature up to 2050 °C. The multimode feature of the sapphire fiber, however, results in modal interference and hence the low visibility of reflection spectrum in Fabry-Perot (FP) cavities. Here we report a higher-order mode suppression technique using tapered graded-index multimode fiber (GIMMF) for the sapphire Fabry-Perot cavity. The tapered GIMMF is designed to couple the fundamental mode from the single-mode fiber to the sapphire FP cavity with low loss together with more than three times suppression on the excited energy percentage of the higher-order modes, significantly enhancing the contrast of the cavity interference signal. A three-wavelength laser-interference method is used to demodulate the cavity length of the multimode sapphire FP sensors, achieving a real-time strain measurement up to 1000 ℃ temperature with 160 kHz sampling frequency. Experimental results show that the sensor can achieve a dynamic range of ±1000 με with the maximum error less than ±10%.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OE.553409 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Real-time dynamic strain measurements under a high temperature environment is important for many applications, e.g. component fault diagnosis of aeroengines.
View Article and Find Full Text PDFWe simulate the optical properties of polymer optical waveguides with different refractive index profiles in their cores as coupling components (edge couplers) between single-mode fiber and SiOx waveguides. In this paper, we focus on the single-mode operation of graded-index (GI) core polymer waveguides, for which we previously demonstrated low propagation loss under multimode operation. We design the optimum core structure (size and index contrast) for different refractive index profiles, and then demonstrate the unique optical properties of GI waveguides contributing to the low optical loss compared to the step-index counterparts, in particular, mode field diameter variation and taper angle tolerance.
View Article and Find Full Text PDFWe experimentally study the spatial beam profile and the spectral broadening at the output of a multimode air-silica microstructure fiber taper, used along the direction of an increasing fiber diameter. By using a laser pump at 1064 nm emitting 60 ps Gaussian beam pulses, we observed a competition between Raman beam cleanup and Kerr beam self-cleaning: the multimode frequency conversion process permits to generate spectral sidebands with frequency detuning from the pump that are difficult to obtain in standard graded-index multimode fibers. The generated supercontinuum spans from 500 nm up to 2.
View Article and Find Full Text PDFThe fulfilment of the adiabatic criterion is indispensable for the realization of a low-loss photonic lantern (PL), concurrently imposing a stringent restriction on the taper transition length of the PL. Here, by relaxing the adiabatic criterion, a low-loss and compact PL based on a step-index double cladding fiber (SI-DCF) is theoretically proposed and experimentally demonstrated. The use of SI-DCF can reduce the mode field diameter (MFD) expansion ratio during the tapering processing and greatly decrease the taper transition length required for adiabatic tapering.
View Article and Find Full Text PDFA slightly tapered graded index multimode fiber (GIMF) is demonstrated as the saturable absorber (SA) for a conventional soliton and tightly bound soliton generation. The SA device is simply a GIMF spliced with single-mode fiber (SMF) at its two ends. The waist diameter of the slightly tapered fiber is ∼23.
View Article and Find Full Text PDF