TY - JOUR AU - Pham Thanh, Binh AU - Nguyen, Thuy Van AU - Pham, Van Hoi AU - Bui, Huy AU - Hoang, Thi Hong Cam AU - Do, Thuy Chi AU - Nguyen, Anh Tuan PY - 2021/09/30 Y2 - 2024/03/28 TI - Highly-sensitive Refractometer Based on a D-shaped Fiber Bragg Grating Integrated into A Loop-mirror Optical Fiber Laser JF - Communications in Physics JA - Comm. Phys. VL - 32 IS - 1 SE - Papers DO - 10.15625/0868-3166/16014 UR - https://vjs.ac.vn/index.php/cip/article/view/16014 SP - 11 AB - <p>In this paper, we report a new type of refractometer based on a D-shaped fiber Bragg grating (FBG) integrated in a loop-mirror optical fiber laser. This proposed sensor is used in wavelength interrogation method, in which the D-shaped FBG is applied as a refractive index (RI) sensing probe and a mirror to select mode of laser. The D-shaped FBG is prepared by the removal of a portion of the fiber cladding covering the FBG by means of side-polishing technique. The D-shaped FBG sensing probe integrated in a loop-mirror optical fiber laser with saturated pump technique, the characteristics of sensing signals have been improved to obtain stable intensity, narrower bandwidth and higher optical signal-to-noise ratio compare to normal reflection configuration. The limit of detection (LOD) of this sensor can be achieved to 2.95 x 10<sup>-4</sup> RIU in the refractive index (RI) range of 1.42-1.44. Accordingly, we believe that the proposed refractometer has a huge potential for applications in biochemical-sensing technique.</p> ER -