Related Experiment Video
Updated: Feb 6, 2026

09:11
Assessment of Global Ocular Structure Following Spaceflight Using a Micro-Computed Tomography Micro-CT Imaging Method
Published on: October 27, 2020
6.1K
Femtosecond-induced spiral micro-structured SMS fiber structure for refractive index measurement
Optics Express
|August 19, 2018
Summary
A novel fiber optic sensor using a femtosecond laser-inscribed spiral microgroove effectively measures refractive index (RI) changes. This innovative design offers high sensitivity for liquid RI sensing applications.
Area of Science:
- Optics and Photonics
- Fiber Optic Sensors
- Nanofabrication
Background:
- Fiber optic sensors are crucial for real-time monitoring in various fields.
- Existing sensors face limitations in sensitivity and operational range for refractive index (RI) detection.
- Multimode interference (MMI) based sensors offer potential but require structural enhancements for improved performance.
Purpose of the Study:
- To propose and demonstrate a novel single-mode-multimode-single-mode (SMS) fiber structure with a femtosecond laser-induced spiral microgroove for enhanced RI sensing.
- To investigate the impact of the spiral microgroove on multimode interference within the SMS fiber.
- To evaluate the sensing performance, including sensitivity and linear response range, of the fabricated fiber structure.
Main Methods:
- Fabrication of the SMS fiber structure using femtosecond laser inscription to create a spiral microgroove.
- Characterization of the fiber structure's optical properties and response to external perturbations.
- Experimental measurement of the fiber sensor's response to varying liquid refractive indices.
Main Results:
- Successful fabrication of a femtosecond-induced spiral micro-structured SMS (FISM-SMS) fiber.
- Demonstration of multimode interference modulation by the spiral microgroove, sensitive to external RI.
- Observation of a linear RI sensing response in the range of 1.3373-1.4345 RIU.
- Achieved maximum sensitivity of 2144 nm/RIU, with potential for further enhancement by increasing microgroove depth.
Conclusions:
- The FISM-SMS fiber structure is a promising platform for highly sensitive and linear refractive index sensing.
- The spiral microgroove plays a critical role in enhancing the sensor's sensitivity by perturbing multimode interference.
- Further optimization of microgroove geometry can lead to even greater sensing capabilities for liquid RI detection.
Related Concept Videos
Structural Protein Function
30.0K
Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to...
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to...
30.0K
Structures of Solids
17.9K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
17.9K
Structural Isomerism
21.7K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
21.7K
Structure of Lipids
99.0K
Lipids include a diverse group of compounds that are largely nonpolar in nature. This is because they are hydrocarbons that include mostly nonpolar carbon-carbon or carbon-hydrogen bonds. Non-polar molecules are hydrophobic (“water fearing”), or insoluble in water. Lipids perform many different functions in a cell. Cells store energy for long-term use in the form of fats. Lipids also provide insulation from the environment for plants and animals. For example, they help keep aquatic...
99.0K
Viral Structure
74.7K
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
74.7K
Antibody Structure
65.6K
Overview
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
65.6K

