. 2022 May 7;11:128. doi: 10.1038/s41377-022-00811-x

Table 8.

Sensing results, advantages and characteristics of different types of sensing fiber schemes

Schemes	Sensing distance	Spatial resolution	Temperature accuracy	Advantages	Sensing characteristics
Multi-mode fiber sensing	25 km	2.58 m	0.7 °C	Larger backscattering coefficients, and its SNR is higher at an effective sensing distance. It is suitable for the fields which demand a high temperature measurement accuracy, such as petrochemical temperature monitoring, pipeline leakage fields.	(1) The fiber dispersion and attenuation coefficient deteriorate the effective sensing distance. (2) It is easy to stimulate the Raman effect.
Single-mode fiber sensing	25 km	1 m	6.9 °C	The fiber attenuation and fiber dispersion are small. It is suitable for long-distance linear engineering monitoring.	The Raman gain within the effective sensing distance is small. Temperature accuracy is small compared to other sensing schemes.
Few-mode fiber sensing	25 km	1.13 m	1.0 °C	The system combines the advantages of the multi-mode fiber scheme (high Raman gain) and the single-mode fiber sensing scheme (small fiber dispersion).	Few-mode fiber is more expensive compared to other sensing fibers.

Schemes

Sensing distance

Spatial resolution

Temperature accuracy

Advantages

Sensing characteristics

Multi-mode fiber sensing

25 km

2.58 m

0.7 °C

Larger backscattering coefficients, and its SNR is higher at an effective sensing distance.

It is suitable for the fields which demand a high temperature measurement accuracy, such as petrochemical temperature monitoring, pipeline leakage fields.

(1) The fiber dispersion and attenuation coefficient deteriorate the effective sensing distance.

(2) It is easy to stimulate the Raman effect.

Single-mode fiber sensing

25 km

1 m

6.9 °C

The fiber attenuation and fiber dispersion are small.

It is suitable for long-distance linear engineering monitoring.

The Raman gain within the effective sensing distance is small.

Temperature accuracy is small compared to other sensing schemes.

Few-mode fiber sensing

25 km

1.13 m

1.0 °C

The system combines the advantages of the multi-mode fiber scheme (high Raman gain) and the single-mode fiber sensing scheme (small fiber dispersion).

Few-mode fiber is more expensive compared to other sensing fibers.