Hai-Tao Sun

Random Rotary Position Sensor Based on Fiber Bragg Gratings

In this paper a new rotary position sensing structure based on a pair of fiber Bragg gratings (FBGs) is experimentally demonstrated with capability of detecting rotating angle of a rotor which is rotated in arbitrary direction or rotated in the same direction infinitely. Moreover, owing to its miniature size, this structure can also be used for small rotary apparatus as a tiny rotating position sensor. The operation mechanism is mainly based on the difference between the wavelength shifts of two FBGs respectively due to the axial strain caused by bending the cantilever towards the angular direction corresponding to the rotating position of rotary shaft. A deviation of 1.1 degrees for rotary angle detecting is obtained.

A refractive-index fiber sensor by using no-core fibers

A simple, small-size, compact and high-sensitivity refractive-index sensor composed of a short no-core fiber (NCF) about 20 mm in length sandwiched between two pieces of single-mode fibers is proposed in this paper. The index measurement is experimentally demonstrated with the sensitivity of 7792.85 nm/ RIU in the range from 1.440 to 1.454 and 227.14 nm/ RIU in the range from 1.300 to 1.430. This sensing mechanism is based on the induced multi-mode interfering wavelength shift in the no-core fiber when the reflective index of the fiber outside is changed.

A rotational angle sensor based on fiber bragg gratings

A new rotational angle sensor composed of two FBGs glued axially on a metal-rod surface driven bent by attraction of a magnetic disk is proposed. Whenever an external force is applied in the end of this sensor, these two FBGs undergo a strain caused by a shaft rotation to result in their central wavelength shifts respectively. This sensor can precisely to detect the random rotation angle in both static and dynamic conditions. The nice sensing performance including linear response, fine resolution, negligible hysteresis, and long-term stability are experimentally demonstrated.

Development of a robust rotational-angle optical fiber sensor using different-material cantilevers

Abstract. A rotational-angle sensor composed of two Fiber Bragg gratings glued axially on a cylindrical cantilever beam to be bent by the resultant repulsion force of three magnets is designed and proposed for detecting the rotary random position of a rotor. By means of using three different materials on cantilever beams for checking each feature’s effect on this fiber optic sensor, it has been experimentally confirmed that a nearly identical performance is achieved among them. From these experimental results, a maximum deviation of 1.3 deg is obtained and it is in good agreement with the theoretical prediction. As a whole, the cantilever design exploited in this proposed optical fiber sensor configuration is independent of the intrinsic materials used. This sensor can provide a robust kind of technique for accurately measuring the rotational angle or rotational rate of a rotor in an arbitrary rotational direction for a wide range of industrial applications.

A random-rotational angle fiber sensor

This paper has successfully achieved a new type optomechanical rotational angle sensor which consists of two FBGs glued axially on a capillary surface that is driven bent by attraction of a magnetic disk. Whenever an input force exerts on the end of this sensor, these two FBGs undergo strain caused by shaft rotation and result in their central wavelength shifts respectively. This sensor can be used to accurately detect random rotation angle in both static and dynamic conditions except the maximum deviation of 0.876 deg from 195 deg. The excellent sensor characteristics including linear response, fine resolution, negligible hysteresis, and long-term stability are experimentally demonstrated.

Random-rotational angle sensor based on fiber Bragg gratings

A novel rotational-position sensor consists of two FBGs glued axially on a capillary surface and driven bent by attraction of a magnetic disk, which accurately detects random rotation angle in both static and dynamic conditions.

Volatile-organic gas fiber sensor based on air-gap long period fiber grating

A novel optical-fiber sensor based on air-gap long-period fiber grating with a coated zinc-oxide thin-film is proposed for detecting the diallyl disulfide and thiol, which are the main volatile organic compounds ingredients of the pepper.

Refractive index sensor base on hetero-core-structure fiber

A high-sensitivity refractive index sensor composed of a short piece of no-core fiber spliced between two single-mode fibers is experimentally demonstrated with the sensitivity of 7792.85 nm/RIU.