Spatial Division Multiplexing-Based Reflective Intensity-Modulated Fiber Optics Displacement Sensor

Abstract

Due to the benefit of multiple parallel channels within single cladding and easy implementation of multi-input multioutput technique, we present the spatial division multiplexing (SDM)-based reflective intensity-modulated fiber optics displacement sensor (RIMFODS). Under the condition of single-input single-output, we experimentally compare the transfer function of RIMFODS by using a pair of standard single-mode fibers (SSMFs), single seven-core-single-mode fiber, and single seven-core-few-mode fiber. In comparison with the conventional SSMF-based RIMFODS, the use of seven-core-few-mode fiber can reduce the dead zone of measurement range from 200 to 100 μm. Meanwhile, the system sensitivity can be enhanced from 0.14 to 12.2 nW/μm. In particular, with the help of twoinput-five-output technique, the dead zone can be further reduced to 70 μm, with sensitivity reaching as high as 53.87 nW/μm. Finally, we theoretically investigate the effect of both the core size and the core spacing of multicore fiber on the transfer function of RIMFODS. Such an SDM-based RIMFODS with compact footprint has lots of potential to be exploited.

MEMS-Based Reflective Intensity-Modulated Fiber-Optic Sensor for Pressure Measurements

“…When the light propagates in the transmitting fiber, the radial distribution along the fiber axis can achieve an approximately Gaussian distribution. The irradiance of emitted light from the transmitting fiber obeys an exponential law according to [32][33][34]:…”

“…When the light propagates in the transmitting fiber, the radial distribution along the fiber axis can achieve an approximately Gaussian distribution. The irradiance of emitted light from the transmitting fiber obeys an exponential law according to [32][33][34]: Compared with the standard fiber, the fiber with microsphere structure has a higher numerical aperture (NA) [35]. The relationship between the NA of the optical fiber and the light intensity is simulated using the MATLAB software, as shown in Figure 2.…”

A New Method to Design Trifurcated Optical Fiber Displacement Sensors

“…However, this arrangement limits the amount of reflected light, which reduces the working range. Other configurations have been proposed, e.g., a pair of bent-tip optical fibers [23], a hemispherical arrangement of fibers, and even randomly distributed transmitting and receiving fibers [24], [25], or more recently, an OFDS based on a multi-core fiber with seven cores hexagonally arranged [26].…”