Recent progress in long-period fiber grating sensors written by high-frequency CO 2 laser pulses

2005 ◽  
Author(s):  
Yun-Jiang Rao
Keyword(s):  
High Frequency ◽  
Recent Progress ◽  
Laser Pulses ◽  
Fiber Grating ◽  
Long Period Fiber Grating ◽  
Long Period ◽  
Period Fiber Grating

scholarly journals Long-period fiber grating sensors fabrication at high-frequency carbon dioxide laser pulses

2020 ◽  
Vol 1547 ◽  
pp. 012005
Author(s):  
J F Rojas ◽  
S Valencia ◽  
J A Montoya-Cardona ◽  
J L Galvis ◽  
N D Gomez-Cardona
Keyword(s):  
Carbon Dioxide ◽  
High Frequency ◽  
Carbon Dioxide Laser ◽  
Laser Pulses ◽  
Fiber Grating ◽  
Long Period Fiber Grating ◽  
Long Period ◽  
Period Fiber Grating

Strain-Insensitive Simultaneous Measurement of Bending and Temperature Using Long-Period Fiber Grating Inscribed on Double-Clad Fiber with CO2 Laser

2021 ◽  
Vol 21 (3) ◽  
pp. 1883-1889
Author(s):  
Min Seok Kim ◽  
Do Kyung Kim ◽  
Jihoon Kim ◽  
Seul-Lee Lee ◽  
Sungwook Choi ◽  
...  
Keyword(s):  
Simultaneous Measurement ◽  
Optical Fiber Sensor ◽  
Strain Range ◽  
Cost Effective ◽  
Laser Pulses ◽  
Fiber Grating ◽  
Sensor Head ◽  
Long Period Fiber Grating ◽  
Long Period ◽  
Period Fiber Grating

Here we report an optical fiber sensor capable of performing strain-insensitive simultaneous measurement of bending and temperature using a long-period fiber grating (LPFG) inscribed on doubleclad fiber (DCF) with a CO2 laser at ˜10.6 μm. The LPFG inscribed on DCF, referred to as a DC-LPFG, was fabricated by scanning CO2 laser pulses on an unjacketed DCF with a specific period. Due to co-directional mode coupling, the fabricated DC-LPFG has discrete attenuation bands widely distributed over hundreds of nanometers. Among these wavelength-dependent loss dips, adjacent two dips with different resonance wavelengths were selected as sensor indicators for the measurement of bending and temperature. For these two indicator dips designated as dips A and B, their bending and temperature responses were investigated in a curvature range of 4.90 to 21.91 m−1 and a temperature range of 30 to 110 °C. With increasing bending applied to the DC-LPFG at room temperature, dips A and B showed different blue shifts. The bending sensitivities of dips A and B were measured to be approximately −0.77 and 0.51 nm/m−1, respectively. Unlike the bending response, they showed red shifts of different amounts with increasing ambient temperature, while the sensor head (i.e., the DC-LPFG) remained straight without any applied bending. The temperature sensitivities of dips A and B were measured to be ˜0.094 and ˜0.078 nm/°C, respectively. Owing to their linear and independent responses to bending and temperature, bending and temperature changes applied to the DC-LPFG could be simultaneously estimated from the measured wavelength shifts of the two indicator dips using their pre-determined bending and temperature sensitivities. Moreover, in a strain range of 0 to 2200 με (step: 200 με), strain-induced spectral variations of dips A and B were also measured, and the strain sensitivities of dips A and B were evaluated as approximately −0.028 and −0.013 pm/με, respectively. These strain-induced wavelength shifts were so small that they had little effect on the measurement results of bending and temperature. Thus, it is concluded that the fabricated DC-LPFG can be employed as a cost-effective sensor head for strain-insensitive separate measurement of bending and temperature.

Long-period fiber grating fabricated by focused irradiation of femtosecond laser pulses

1999 ◽  
Author(s):  
Yuki Kondo ◽  
Kentaro Nouchi ◽  
Tsuneo Mitsuyu ◽  
Masaru Watanabe ◽  
Peter G. Kazansky ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Fiber Grating ◽  
Long Period Fiber Grating ◽  
Long Period ◽  
Period Fiber Grating

Arc Radius-Chirped Long-Period Fiber Grating by High Frequency CO2-Laser Writing

2021 ◽  
pp. 1-1
Author(s):  
Yanxin Zhang ◽  
Weigang Zhang ◽  
Pengfei Wu ◽  
Zhe Li ◽  
Han Gao ◽  
...  
Keyword(s):  
Co2 Laser ◽  
High Frequency ◽  
Fiber Grating ◽  
Laser Writing ◽  
Long Period Fiber Grating ◽  
Long Period ◽  
Period Fiber Grating
Sign in / Sign up

Export Citation Format

Share Document