The principle and characteristics of fiber optic grating sensors-INNO

Dalam beberapa tahun kebelakangan ini, with the rapid development of fiber optic technology, a large number of new types of fibers and fiber optic devices have emerged. Pada masa yang sama, with the use of various new light sources and fiber optic detectors, fiber optic sensing technology has made breakthrough progress in technological development and practical applications.

Penderia gentian optik, as an important application of optical fibers, are receiving increasing attention due to their small size, ringan, dan sensitiviti yang tinggi. They have unparalleled advantages in preventing magnetic field interference, kakisan, kalis air, and high temperature and pressure resistance compared to traditional electronic sensors.
Fiber optic grating sensing technology is an important branch of the field of fiber optic sensing technology. Prinsip penderiaannya ialah panjang gelombang tengah parut gentian optik berubah disebabkan oleh perubahan dalam parameter fizikal luaran. Dengan memantau saiz panjang gelombang tengah parut gentian optik, maklumat khusus parameter fizikal diperolehi, dengan itu mencapai penderiaan. Penderia parut gentian optik ialah penderia gentian optik termodulat panjang gelombang yang, sebagai tambahan kepada ciri-ciri penderia gentian optik biasa, mempunyai ketepatan pengukuran yang lebih tinggi, resolusi yang lebih baik, dan lebih sesuai untuk pengukuran teragih.

Prinsip dan Ciri-ciri Aplikasi bagi Penderia Grating Fiber Bragg

Disebabkan oleh kesan akibat cahaya, kesan parut boleh dihasilkan dalam gentian terdop germanium, mengakibatkan pengeluaran parut gentian pertama di dunia berjaya. Sejak itu, prinsip asas, kaedah fabrikasi, and practical applications of fiber Bragg gratings have been extensively studied by a large number of researchers.
The main material of optical fibers is quartz, which is composed of a core layer and a cladding layer, and the outer layer is protected by a coating layer. By doping the core layer, the refractive index (n1) of the core layer is greater than that of the cladding layer (n2), forming an optical waveguide where light can propagate within the core layer. When the optical fiber is modulated by external factors, the refractive index of the core layer undergoes periodic changes, forming a fiber grating. The phase mask method is currently the most convenient and effective method for producing fiber Bragg gratings, simplifying the production process and reducing production costs. There are various types of fiber Bragg gratings, among which the typical one is fiber Bragg grating (FBG), which is also one of the earliest developed and most widely used fiber Bragg gratings.

Basic Sensing Principles of Fiber Bragg Grating

By forming a spatial phase grating on the fiber optic core in a certain way, when light passes through the fiber optic grating, mode coupling occurs between the forward and backward transmission of the fiber optic core modes, causing the forward transmission of the fiber optic core mode to transfer to the backward transmission of the fiber optic core mode. iaitu, the incident light with a wavelength reflected at the center of the fiber optic grating (l B) is reflected, and the center reflection wavelength of the parut gentian optik dipengaruhi oleh ketegangan dan suhu. Dengan memantau magnitud pantulan tengah panjang gelombang parut gentian optik, pengesan terikan dan suhu yang sepadan boleh dicapai. Parameter fizikal lain seperti tekanan, anjakan, dll. boleh ditukar kepada faktor seperti suhu atau tekanan yang secara langsung memberi kesan kepada parut gentian optik
Dengan berbuat demikian, Kisi gentian Bragg boleh digunakan untuk mencapai pengesanan pelbagai parameter fizikal.

Ciri-ciri aplikasi jeriji gentian optik

Berdasarkan bahan dan ciri-ciri struktur serat Bragg grating, serta prinsip penderiaan mereka, mereka mempunyai banyak kelebihan yang ketara.

(1) Saiz kecil, ringan, struktur ringkas, dan rupa yang berubah-ubah.

Biasanya, serat Bragg gratings sahaja 3-5 cm panjang dan mempunyai gentian ringan. Kepala penderiaan parut Bragg gentian adalah kecil, fleksibel, and portable device that can be packaged according to the actual use of fiber Bragg grating sensors to meet different sensing needs.

(2) Good chemical stability.

The main component material of fiber optic grating is silicon dioxide, which has good chemical stability. Oleh itu, fiber optic grating sensors have strong corrosion resistance and are suitable for harsh environments with chemical corrosion, as well as various biological environments.

(3) Good physical stability.

The main component material of fiber optic gratings is silicon dioxide, so fiber optic gratings are electrically insulating, waterproof, and resistant to high temperature and high pressure.

(4) Tidak terjejas oleh gangguan elektromagnet.

Due to the working principle of fiber optic gratings, they have the characteristic of being immune to electromagnetic interference and are particularly suitable for harsh environments with high radiation intensity, such as medical detection in special environments such as nuclear magnetic testing.

(5) High sensing sensitivity.

Fiber Bragg Grating achieves sensing by monitoring changes in the reflected wavelength of the center, resulting in high measurement sensitivity. Due to the extremely small changes in many medical detections, some ordinary sensors cannot measure the changes. Oleh itu, this characteristic of fiber Bragg grating ensures its applicability in the field of medical device sensing.

(6) Ketepatan pengukuran yang tinggi.

Based on the sensing principle of fiber optic grating, it is not affected by other factors such as light sources, and its measurement accuracy is high. Namun begitu, medical sensors have high requirements for measurement accuracy, which makes the characteristic of fiber optic grating better meet the measurement accuracy requirements of medical sensors.

(7) Pengukuran masa nyata yang diedarkan.

Multiple multiplexing techniques can be used to connect multiple fiber Bragg gratings in series, forming a distributed sensing network to measure the physical quantities of multiple points. The measurement data is transmitted in real-time to the detector through optical fibers, ultimately achieving real-time detection of multiple physical quantities. This feature can meet the requirements of multi parameter measurement for medical sensors.

(8) Julat ukuran yang luas.

By designing the structure and packaging of fiber Bragg gratings, various physical parameters such as strain, suhu, tekanan, rotational speed, pH value, and humidity can be measured.