Polarimetric multilongitudinal‐mode distributed Bragg reflector fiber laser sensor for strain measurement

Abstract

A polarimetric multilongitudinal‐mode distributed Bragg reflector fiber laser sensor is proposed and experimentally demonstrated. We have theoretically analyzed the mode beat mechanism of this laser sensor, which is verified by the experimental observation, and its application in strain measurement has also been studied. Experimental results indicate that both of the longitudinal mode beat (LMB) and birefringence‐induced polarization mode beat signals have linear strain dependence, and the coefficients of determination reach 0.9991 and 0.9908, respectively. One possible way to improve the sensitivity of LMB‐based sensing has been investigated as well. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2559–2563, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24671

Fiber birefringence measurement based on a beat‐frequency‐interrogated multilongitudinal‐mode distributed bragg reflector erbium‐doped fiber laser

“…Considering the laser beat originated from different longitudinal modes with birefringence‐induced mode splitting, a series of frequencies would exist in the laser beat frequency spectrum, as discussed in Ref. 18. Figure 2 shows the initial laser beat frequency spectrum in a periodic pattern, as no strain is applied.…”

“…Similar to the strain sensing system reported in Ref. 18, our proposed fiber birefringence measurement system is basically constituted by a multilongitudinal‐mode DBR fiber laser consisting of a piece of erbium‐doped fiber (EDF) with two fiber Bragg gratings (FBGs) as cavity reflectors. A 980‐nm pump laser diode (LD) is used as the pump source, and 18.5‐cm EDF serves as the gain medium.…”

“…As fiber birefringence is highly sensitive to environmental parameters, such as temperature, strain, and pressure, polarimetric fiber laser sensors based on beat frequency interrogation have attracted much research interest in the past few years [14–17]. Recently, we have developed an active strain sensor based on a multilongitudinal‐mode fiber laser [18]. As an extension of this work and to overcome the aforementioned disadvantages of conventional fiber birefringence measurement approaches, in this article, a novel scheme for fiber birefringence measurement is proposed and experimentally demonstrated.…”

Multilongitudinal-mode fiber laser temperature sensor and its applications in the measurement of temperature dependence of fiber birefringence

“…the longitudinal mode beat between different longitudinal modes (LMB) and the birefringence-induced polarization mode beat (PMB) would co-exist in the beat frequency spectrum. As a result, a periodic frequency pattern would appear and could be described as the following expression [8]:…”

Sensitivity and stability characterization of linear cavity erbium‐doped fiber laser for pressure measurement

“…The accuracy of this system is much better compared to using intensity. Yet, most active sensing systems are focusing on strain sensing system [14, 15]. This article presented a fiber laser pressure sensor for measuring high static pressure by incorporating fiber Bragg grating (FBG) as sensor head.…”