Analysis on the effect of UV beam intensity profile on the refractive index modulation in phase mask based fiber Bragg grating writing

The method of ultrashort pulse filamentation induced refractive index modification is employed to inscribe fiber Bragg grating (FBG) in single-mode optical fiber (SMF). Line-by-line index inscription technique is used to write refractive index modulation in the core of SMF. The proposed pulse filamentation based index modification enables controlled and flexible writing of FBGs in optical fibers. Performance analysis of the fabricated FBG has been carried out for temperature, contact force, pressure, and axial strain sensing. The in-fiber FBG exhibits sensing performance very similar to FBGs commercially available to date. Then, the written FBG is engineered to demonstrate highly sensitive contact force sensor.

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Method for precise evaluation of refractive index modulation amplitude inside the volume Bragg grating recorded in photo-thermo-refractive glass

Optics Express ◽

10.1364/oe.26.000157 ◽

2018 ◽

Vol 26 (1) ◽

pp. 157 ◽

Cited By ~ 2

Author(s):

Peng Chen ◽

Dongbing He ◽

Yunxia Jin ◽

Junming Chen ◽

Jingyin Zhao ◽

...

Keyword(s):

Refractive Index ◽

Bragg Grating ◽

Refractive Index Modulation ◽

Modulation Amplitude ◽

Volume Bragg Grating ◽

Precise Evaluation ◽

Index Modulation

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Transverse Asymmetry of the Index Modulation Profile in Few-Mode Fiber Bragg Grating

Photonics ◽

10.3390/photonics8030087 ◽

2021 ◽

Vol 8 (3) ◽

pp. 87

Author(s):

Peihong Guan ◽

Min Tang ◽

Min Cao ◽

Yuean Mi ◽

Mei Liu ◽

...

Keyword(s):

Fiber Bragg Grating ◽

Attenuation Coefficient ◽

Optical Communication ◽

Mode Conversion ◽

Bragg Grating ◽

Mode Division Multiplexing ◽

Single Side ◽

Side Illumination ◽

Index Modulation ◽

Great Potential Application

The transverse asymmetry of the index modulation profile in the asymmetric few-mode fiber Bragg grating (FM-FBG) was investigated. The transverse asymmetry of the index modulation profile will lead to mode conversion between modes with the different azimuthal orders, and this asymmetry is characterized by the attenuation coefficient α. We evaluated that the value of attenuation coefficient α was 0.2 μm−1, and grating amplitude χ was 2.8 × 10−4 for FM-FBG inscribed by UV single-side illumination. We found that the optimized value of α was 0.16 μm−1, at which the maximum mode conversion efficiency of LP01–LP11 can be achieved. The results of this paper provide great potential application in few-mode fiber (FMF) devices and mode division multiplexing (MDM) optical communication.

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Optical properties of a photopolymer with large refractive index modulation for holographic application

10.1117/12.559329 ◽

2004 ◽

Author(s):

Chang-Won Shin ◽

Nam Kim ◽

Won-Sun Kim ◽

Yong-Cheol Jeong ◽

Jung-Ki Park

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Refractive Index Modulation ◽

Index Modulation

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Development of an Optical Fiber Sensor with a D-shaped Fiber Bragg Grating Integrated in a Loop-mirror Optical Fiber Laser as a High Sensitivity Refractometer

Communications in Physics ◽

10.15625/0868-3166/16014 ◽

2021 ◽

Vol 32 ◽

Author(s):

Binh Pham Thanh ◽

Thuy Van Nguyen ◽

Van Hoi Pham ◽

Huy Bui ◽

Thi Hong Cam Hoang ◽

...

Keyword(s):

Refractive Index ◽

Optical Fiber ◽

Fiber Laser ◽

Fiber Bragg Grating ◽

Limit Of Detection ◽

Optical Fiber Sensor ◽

High Sensitivity ◽

Optical Signal ◽

Bragg Grating ◽

Loop Mirror

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 10-4 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.

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