Temperature sensing scheme based on fiber ring microwave photonic filter with erbium doped fiber amplification

Abstract

The temperature sensing scheme based on fiber ring microwave photonic filter (MPF) with erbium doped fiber amplification (EDFA) is proposed and experimentally demonstrated. The fiber ring is used as the time delay element, as well as a sensing element, and by introducing an EDFA to compensate the loss in the fiber ring, the number of the effective sampling taps and thus the suppression ratio are increased. When the EDFA power is set at 0.74 mW, the 3 dB bandwidth of the passband and suppression ratio of the MPF are estimated to be 82.5 kHz, and 15 dB, respectively. The superior sharp passband characteristics make the fiber ring MPF with an EDFA very advantageous for sensing. In our experiment, temperature sensing by using the fiber ring MPF with an EDFA has been carried out for demonstration. The temperature variations induce refractive index changes of the fiber, which will change the time delay of each tap of the fiber ring MPF, and as a result, the FSR of the MPF will be changed. By tracing the peak point shift of the MPF's passband, the temperature variations can be monitored. Our experimental results show that there is a good linear relationship between temperature change and frequency shift, and by measuring passbands with different frequencies, different sensitivity can be obtained. In our experiment, the sensitivity is estimated to be −5.89, −11.74, and − 17.7 kHz/°C, respectively, when the passbands at 0.8, 1.6, and 2.4 GHz are adopted for temperature monitoring.

Temperature sensing technique by using a microwave photonics filter based on an actively mode‐locked fiber laser

“…The peak frequency of the passband can be expressed as: 13 When temperature changes, the frequency shift of the j th passband can be derived as: where is length of the sensing fiber, is the length of the cavity except the sensing fiber. is thermo‐optic effect induce refractive index changes, and it should be noted that here only the thermo‐optic effect is taken into account, because the coefficient of thermal expansion is small enough compared to the thermo‐optic coefficient for neglecting.…”

“…With the rapid development of microwave photonics technology, it has been employed in the sensing systems due to the advantages of low cost, high sensitivity, and easy implementation 12 . Yang et al have proposed a temperature sensing scheme based on a fiber ring microwave photonics filter (MPF) with EDF amplification, and the sensitivity is 11.74 kHz/°C when the passband at 1.6 GHz is adopted for temperature monitoring 13 . Huang et al have proposed a microwave interrogated sapphire fiber Michelson interferometer for high‐temperature sensing, and the sensor shows a good sensitivity in the temperature range of 100 ~ 1400°C 14 .…”

“…12 Yang et al have proposed a temperature sensing scheme based on a fiber ring microwave photonics filter (MPF) with EDF amplification, and the sensitivity is 11.74 kHz/ C when the passband at 1.6 GHz is adopted for temperature monitoring. 13 Huang et al have proposed a microwave interrogated sapphire fiber Michelson interferometer for high-temperature sensing, and the sensor shows a good sensitivity in the temperature range of 100 ~1400 C. 14 Yang et al have proposed a high-sensitivity temperature sensor based on a Brillouin fiber microwave generator, where small variations in optical domain are converted into considerable variations in electronic domain. 15 In this article, a temperature-sensing scheme by using an MPF based on an actively mode-locked fiber laser (MLFL) is proposed and experimentally demonstrated.…”

A Temperature Independent Inclinometer Based on a Tapered Fiber Bragg Grating in a Fiber Ring Laser

“…Martin-Vela et al reported an inclinometer based on a fiber ring laser [ 29 ], where a thin core fiber modal interferometer worked as a filter for the system. Moreover, Fu reported a temperature sensing system based on a fiber ring microwave photonic filter (MPF) [ 30 ], which combined microwave photonics with a fiber ring laser. Mateusz proposed a FRL sensor which can simultaneously measure temperature and humidity [ 31 ].…”

Fiber sensor based on Fabry‐Perot/Mach‐Zehnder hybrid interferometer for transverse load and temperature

“…Fiber optic sensors have the advantages of high sensitivity, compact structure, anti-electromagnetic interference, and remote control, [1][2][3] which are increasingly applied to the detections of basic physical parameters, such as temperature, [4][5][6] transverse load, 7,8 refractive index, [9][10][11] and strain. [12][13][14] With the development of science and technology, multi-parameter detections have become a hot topic in recent years, for instance, integrated optic-fiber sensor based on enclosed EFPI and structural phase-shift for discriminating measurement of temperature, pressure and RI temperature and refractive index, 15 transverse load and refractive index fiber sensor based on photonic crystal fiber, 16 a sawtooth stressor-assisted highly birefringent fiber Bragg grating for temperature and strain measurement.…”