Long period grating in a multimode cyclic transparent optical polymer fiber inscribed using a femtosecond laser

A novel method for fabricating long period grating in grapefruit photonic crystal fiber (GPCF) is proposed and demonstrated. An 800nm femtosecond laser is adopted to scan a section of GPCF periodically point-by-point, resulting in effective refractive index periodic demodulation. High resonance of ~17dB is obtained with a grating length of 30 mm. The temperature sensitivity of resonant wavelength 0.03 nm/°C is obtained from 20°C to 120 °C. In addition, the relationship between resonant wavelength and surrounding refractive index (SRI), when LPFG immersed in refractive index of solution of different index, is also researched.

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A femtosecond laser-inscribed fine-core long-period grating with low temperature sensitivity

Chinese Optics ◽

10.37188/co.2020-0015 ◽

2020 ◽

Vol 13 (4) ◽

pp. 737-744

Author(s):

MING Xin-yu ◽

◽

GUO Qi ◽

XUE Zhao-kang ◽

...

Keyword(s):

Low Temperature ◽

Femtosecond Laser ◽

Temperature Sensitivity ◽

Long Period Grating ◽

Long Period

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The spectral characteristics of femtosecond laser inscribed long period grating bend sensors written into a photonic crystal fibre

10.1117/12.786664 ◽

2008 ◽

Cited By ~ 1

Author(s):

T. Allsop ◽

K. Kalli ◽

K. Zhou ◽

G. Smith ◽

D. J. Webb ◽

...

Keyword(s):

Photonic Crystal ◽

Femtosecond Laser ◽

Spectral Characteristics ◽

Long Period Grating ◽

Photonic Crystal Fibre ◽

Long Period

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Hybrid LPG-FBG Based High-Resolution Micro Bending Strain Sensor

Sensors ◽

10.3390/s21010022 ◽

2020 ◽

Vol 21 (1) ◽

pp. 22

Author(s):

Song-Bi Lee ◽

Young-Jun Jung ◽

Hun-Kook Choi ◽

Ik-Bu Sohn ◽

Joo-Hyeon Lee

Keyword(s):

High Resolution ◽

Femtosecond Laser ◽

Practical Method ◽

Bragg Grating ◽

Wavelength Shift ◽

Practical Implementation ◽

Long Period Grating ◽

Optical Wave ◽

Long Period ◽

Signal Pattern

Sensitivity and reliability are essential factors for the practical implementation of a wearable sensor. This study explores the possibility of using a hybrid high-resolution Bragg grating sensor for achieving a fast response to dynamic, continuous motion and Bragg signal pattern monitoring measurement. The wavelength shift pattern for real-time monitoring in picometer units was derived by using femtosecond laser Bragg grating processing on an optical wave path with long-period grating. The possibility of measuring the demodulation system’s Bragg signal pattern on the reflection spectrum of the femtosecond laser precision Bragg process and the long-period grating was confirmed. By demonstrating a practical method of wearing the sensor, the application of wearables was also explored. It is possible to present the applicability of sophisticated micro transformation measurement applications in picometer units.

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