Linear Fiber Laser Configurations for Optical Concentration Sensing in Liquid Solutions

• Type: Article in International Scientific Journal
• Date: 2024

Authors

Soares, L (Author) Other; Perez-Herrera, RA (Author) Other; Novais, S (Author) Other; A. Ferreira (Author) FEUP; Susana Silva (Author) FCUP; Frazao, O (Author) FCUP

Journal

Title: Photonics

Vol. 11

Final page: 393

Publisher: MDPI

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 1 Citation

Other information

Authenticus ID: P-00Z-WZF

DOI: 10.3390/photonics11050393

Abstract (EN): In this study, different configurations based on linear fiber lasers were proposed and experimentally demonstrated to measure the concentration of liquid solutions. Samples of paracetamol liquid solutions with different concentrations, in the range from 52.61 to 201.33 g/kg, were used as a case-study. The optical gain was provided by a commercial bidirectional Erbium-Doped Fiber Amplifier (EDFA) and the linear cavity was obtained using two commercial Fiber Bragg Gratings (FBGs). The main difference of each configuration was the coupling ratio of the optical coupler used to extract the system signal. The sensing head corresponded to a Single-Mode Fiber (SMF) tip that worked as an intensity sensor. The results reveal that, despite the optical coupler used (50:50, 60:40, 70:30 or 80:20), all the configurations reached the laser condition, however, the concentration sensing was only possible using a laser drive current near to the threshold value. The configurations using a 70:30 and an 80:20 optical coupler allowed paracetamol concentration measurements with a higher sensitivity of (-3.00 +/- 0.24) pW/(g/kg) to be performed. In terms of resolution, the highest value obtained was 1.75 g/kg, when it was extracted at 20% of the output power to the linear cavity fiber laser configuration.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9