Abstract
A fiber in-line, multimode coupling interferometer with a trench-embedding, fiber taper probe is proposed and fabricated by femtosecond-laser-induced water breakdown. The reflection-type taper probe is used for gas refractive index (RI) detection from 1.0001143 to 1.0002187 and temperature sensing from 50°C to 500°C. The largest RI sensitivity of the taper probe embedded with a trench at a width of 18.4 μm is 669.502 nm/RIU for hybrid nitrogen and helium. Temperature sensitivity is 9.97 pm/°C and it shows good linearity through the whole testing range. The new-type multimode interferometer is appropriate for high-accuracy gas RI detection of micrometer-scale spaces and wide-range temperature compensation can be realized.
| Original language | English |
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| Pages (from-to) | 1028-1032 |
| Number of pages | 5 |
| Journal | Applied Optics |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 20 Feb 2014 |