A Static Axial Strain Fiber Ring Cavity Laser Sensor Based on Multi-Modal Interference

Abstract

A novel and simple static strain fiber ring cavity laser sensor based on all-fiber single-mode-multimode-singlemode (SMS) structure filter is proposed and experimentally demonstrated. When an axial strain is applied on the SMS filter, the pass-band varies, resulting in shifts of the lasing central wavelength. Thus, the value of axial strain imposed on the structure can be calculated by the monitored central wavelength of the system via the function relationship between these two parameters. Compared with the conventional axial strain sensing system based on an SMS fiber structure, the proposal exhibits additional advantages in terms of high optical signal to noise ratio (∼50 dB) and narrow 3 dB bandwidth (<0.05 nm) apart from simple fabrication and low cost. A good linearity is obtained between the axial strain applied on the SMS filter and central wavelength of the proposed laser sensing system with R 2 of 0.99954, and high sensitivity of 2.3 pm/με in the range 0-2333 με is successfully achieved.Index Terms-Measurement, modal interference, fiber ring cavity laser.

Highly Sensitive Axial Strain Fiber Laser Sensor Based on All-Fiber Acousto-Optic Tunable Filter

“…7 and 2.3pm/με in Ref 20,. the fiber laser sensor based on all fiber AOTF has a higher sensitivity, and the sensitivity of this fiber laser sensor also can be improved by etching the SMF of all…”

“…The central wavelength of the fiber laser sensor varies with the change of the axial strain. The proposed fiber laser sensor has advantages of high OSNR and narrow bandwidth, and a sensitivity of about 0.148nm/με can be achieved, which is much higher than the one of 60pm/με in the Mach-Zehnder interferometer based fiber strain sensor [5], 0.23pm/με in the Sagnac interferometer based fiber strain sensor [7] and 2.3pm/με in the Multi-Modal Interference based fiber laser strain sensor [20]. Fig.…”

“…Since a fiber Bragg grating based laser sensor has been proposed by Koo et al [17], some different types of fiber laser sensors have been demonstrated and used in many sensing fields, such as strain sensing [18]- [20], temperature sensing [21], bending sensing [22], refractive index sensing [23], [24], magnetic sensing [25] and simultaneous measurement [26]. According to the monitoring parameter, optical fiber laser sensors generally can be divided into two kinds: one monitors the central wavelength of the fiber laser sensor, and the other measures the beat frequency of the fiber laser sensor.…”

Erbium Ring Fiber Laser Cavity Based on Tip Modal Interferometer and Its Tunable Multi-Wavelength Response for Refractive Index and Temperature

“…The appearance of other lasing modes was evident as the temperature increased because of the modal competitions was similar for all the lasing modes involved. It is well recognized that fiber-optic interferometers exhibit a suitable sensitivity for refractive index and temperature variations [44]; however, the ring laser cavity represents an alternative method to extract phase information [1][2][3][4][5][6][7][8][9]. In analyzing peaks P2, P3, and P6, the following thermal-wavelength relations can be expected: 21.01 pm/°C (P2), 16.99 pm/°C (P3), and 16.97 pm/°C (P6), as well as adequate linear responses of 0.96306 (P2), 0.99507 (P3), and 0.9890 (P6).…”

“…For several decades, the ability to generate tunable or switched multi-wavelength fiber lasers has been one of the focuses pursued by the fiber laser community. These lasers are associated with many reliable applications related to multi-wavelength spectra such as optical fiber sensors [1][2][3][4][5][6][7][8][9], spectroscopy systems [10], biomedical imaging [11], telecommunications [12], microwave photonics [13], and radio frequency optical domain systems [14]. These applications require achieving compact configuration, stable emission, narrow linewidth, and adequate spacing mode.…”