| Autor: |
Valeriy E. Karasik, Stanislav G. Sazonkin, A. O. Chernutsky, Dmitriy A. Dvoretskiy, Ilya O. Orekhov, Yan Zh. Ososkov, Alexey Pniov |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
Optical Sensors 2019. |
| DOI: |
10.1117/12.2520385 |
| Popis: |
Nowadays fiber optic Raman distributed temperature sensors (RDTS) are broadly used for e.g. fire detection, gas leaks detection in pipelines and aircraft icing monitoring. The most common sources of probe pulses for RDTS are CW lasers with external intensity modulation or Q-switched lasers with a pulse duration of several tens of nanoseconds which limits the RDTS effective spatial resolution to a few meters. In this paper we have developed an Er-doped ultrashort pulse (USP) mode-locked fiber laser and implemented it to Raman distributed temperature sensor.This feature allow us to achieve high spatial resolution (down to several centimeters) and high signal-to-noise ratio in the receiving system. An all-fiber erbium-doped laser of 180 fs pulse duration and an average output power of 30 mW was used as a source of probing pulses. We have studied limiting factors of fiber sensor effective length such as high pulse repetition rate of 12.2 MHz and intensity noise of the USP laser (relative intensity noise RIN ~ 6.3 ∙ 10-4). Furthermore, the peak power of the USP laser has to be at kW level to get high signal-to-noise ratio in the receiving system and pulse duration < 100 ps at full-width-half-maximum for desirable spatial resolution of ~2 cm. Moreover, we have developed an experimental prototype of RDTS with the spatial resolution of ~ 0.1 m limited by the receiving system according to the detector bandwidth of 2 GHz, the effective sensor length of 3 m and ±1.5 °C temperature measurement error. As a result, a list of requirements for a new laser source for distributed temperature sensor was formulated. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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