Results in Physics 10 (2018) 743–750
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Review of optical fibers-introduction and applications in fiber lasers a
Satish Addanki , I.S. Amiri a b c
b,c,⁎
, P. Yupapin
T
b
Department of Railroad Integrated Systems, Woosong University, 171, Dongdaejeon-ro, Dong-gu, Daejeon-34606, Republic of Korea Computational Optics Research Group, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Viet Nam Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Viet Nam
A R T I C LE I N FO
A B S T R A C T
Keywords: Optical communications Optical technology Optical devices Fiber lasers Waveguide Optical fibers
The optical fibers which are considered as waveguides can be applied to light transmission applications. The core part of the optical fiber is surrounded by a glass or plastic layer called cladding which is characterized by the refractive index that is lower compared to the core refractive index. The total internal reflection phenomena are necessary for the fine confinements of the light within the waveguide. Basically, optical fibers can be categorized based on the structure, modes number, refractive index profile, dispersion, signal processing ability, and polarization. In this report, we focus on the first three common types of optical fibers. As a common application of the fibers, these can be used in fiber lasers to create and amplify a narrow intense beam of coherent and monochromatic light. Fabrication of optical fiber involves three stages such as the preform formation. Modified chemical vapor deposition (MCVD) method is a known technique, which can be used to fabricate the optical fibers. Optical fiber sensors are well known for wide range applications in optics and photonics. As a sensing application, optical biosensors can be made based on the refractive index changes that used widely for detection of biomolecules in their natural forms.
Introduction Light plays an important role in everyday lives. Light is used in optoelectronics and optical fiber telecommunication for data transmission, from compact disc players where a laser reflecting off a CD transforms the returning signal into music, to laser printers and digital cameras [1–5]. It allows for computers and telephone lines to be connected to one another by optical fiber cables. It found application in many areas such as optical fiber lasers, optical fiber interferometers, sensors, and optical fiber modulators [6]. In medicine, light is used for image productions which are used in hospitals and lasers that execute eye surgery [7]. Light extends through a far greater spectrum than the human eye can see. In several applications such as optical fiber transmission, the electromagnetic radiation ranges from 850 nm, 1310 nm, and 1550 nm, where it is called the near infrared range. Essentially, light consists of a series of electromagnetic waves, with have properties of light-particles. If light considered as a particle, it referred to a stream of photons which are moving from one point to another [8]. Photons are similar to electrons and these can be described as primary particles of light. When light is applied to optical fiber transmission, the particle nature of the light is of lesser importance compared to their wave nature. Generally, light is understood to have possessed a dual nature. Electromagnetic spectrum consists of ⁎
electromagnetic waves including frequencies below one hertz to above 1025 Hz, which are corresponding to wavelengths from thousands of km (kilometers) down to an atomic nucleus size. Therefore, several separated bands are included in the electromagnetic frequency range, where each frequency band includes different electromagnetic waves which are recognized by different names such as the radio waves, microwaves, infrared, visible light, ultraviolet, X-rays beginning from low frequencies (longer wavelength) to high frequencies (shorter wavelength). Fig. 1 shows the electromagnetic spectrum which allows us to locate the radiation used in optical fiber transmission. The light is an electromagnetic radiation included in the electromagnetic spectrum. The light refers to the visible range of the electromagnetic spectrum that can be seen by the human eye [9]. The wavelengths included in the visible range are between the 400–700 nm (nanometers) which placed between the infrared and the ultraviolet frequency bands. The corresponding frequency range for the visible range is 430–750 THz (terahertz). The optical fibers are waveguide utilized for light transmission. There are three most important components of optical fibers such as the core which is usually prepared from the glass. The core is surrounded by another glass or plastic layer called cladding which is characterized by a lower refractive index material compared to the core material.
Corresponding author at: Ton Duc Thang University, Ho Chi Minh City, Viet Nam. E-mail address:
[email protected] (I.S. Amiri).
https://doi.org/10.1016/j.rinp.2018.07.028 Received 18 June 2018; Received in revised form 20 July 2018; Accepted 22 July 2018 Available online 29 July 2018 2211-3797/ © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).
