Patch cord redefined as an Optical or Electrical fiber optic cable

A patch cord or patch cable is an optical or electrical cable which is used to connect one optical or electronic device. Connected devices such as a miniature spectrometer to another for signal routing. Devices of different types are connected with a patch cable. Patch cord is also known as patch lead. The term patch cord is sometimes used as well, but it's often associated more with non-network types of cables such as those for wiring stereo components. The term "patch" came from early use in radio studios and telephony studios. Extra equipment kept on standby could be temporarily substituted for failed devices which came from early use in radio studios and telephony studios. This cord is a key player for indoor use, like in server rooms or in data centers. It is known for its superior adaptability and improved security, featuring excellent reliability, this cord has ranked the best choice for applications where conventional copper cables fail to reach.

Figure 1: Patch Cord- an optical or electrical cable

A patch cable is normally made of coaxial cabling, but it also could consist of fiber optic, shielded or unshielded CAT5/5e/6/6A, or single-conductor wires. A patch cable always has connectors on both ends, which means it's not as permanent of a solution as some cables like pigtails or blunt patch cables. These are similar to patch cables but have exposed bare wires on one end that is meant to be connected directly and permanently to a terminal or other device.

Figure 2: Patch Cords used for superior adaptability, improved security and excellent reliability

There are many different kinds of patch cables. The most common are CAT5/CAT5eethernet cables linking a computer to a nearby network switch, hub, or router, a switch to a router, etc.

A lensed patch cord or patch cable probe has been made with a ball lens packaged in a metal cylinder. Optical coherence tomography could be implemented by simply placing a ball lens directly in front of a fiber patch cable, potentially disposable sampling probe and a compact. To achieve a sufficiently long working distance and a good transverse resolution at the same time, the proper ball lens diameter and the distance between the ball lens and the fiber patch lead were investigated. Experimentally, sometime a working distance that up to 5.2 mm, 3 dB bandwidth of 2 mm, and the transverse resolution of 16 μm were achieved. With the patch lead probe, a common path swept-source OCT system was implemented and used to demonstrate the feasibility as the dedicated probe for dentistry.

The variety of specialty Optical fibers based on modes and structures

Optical fiber cable has a complex design and structure. This type of cable has an outer optical coverage that surrounds the light and traps it within a central core. It is a thin, flexible, adaptable, transparent fiber which is made of silica. It is a flexible transparent material consisting of core & cladding which is used for transmission of light rays based on refraction of light.

Figure 1: Fiber optic construction

Optical fiber is the basic transmission medium for fiber-optic communication. These include the concept and classification of propagation modes along the fiber, single mode condition, numerical aperture, mechanisms and specifications of optical attenuation and dispersion, as well as nonlinearities of optical fiber. While dispersion specifies mode-dependent or wavelength-dependent propagation speed of optical signal propagating in an optical fiber, which are both linear effects, nonlinear effects such as stimulated Raman scattering, stimulated Brillouin scattering, and power-dependent refractive index known as Kerr effect nonlinearity may also affect wave propagation in optical fiber.

Although standard multimode and single-mode fibers are most often used in optical communication systems, a variety of specialty fibers have also been developed for special application.

Figure 2: Light transmitted through the core of Optical Fiber 

The optical performance of solid-core polymer-based microstructured optical fibers are Theoretical model developed earlier is utilized for solid-core triangular air/polymer microstructured optical fibers (MPOFs). The scalar variational approach is implemented for evaluating the fundamental modal characteristics of polymer-based MOFs. Effective index for higher-order mode at terahertz (THz) regime is evaluated and the cut-off conditions are also identified. Coupling characteristics of long-period gratings (LPGs) in MPOF has been examined. Sensitivity coefficient is explored for realizing efficient coupling in the evanescent field-based sensing applications.

Types of optical fiber

- Based on the structures given by the following details:

• Planar waveguide fiber :- This type of fiber is made of the rectangular block containing three layers as the base, light guide, and coating. The refractive index of the base and that of the coating are lower than other layers.

• Cylindrical optical fiber :- This is made up of the core, typically glass where light passes through. This core is also surrounded by a cylindrical layer of material which has a lower refractive index and is known as cladding. The refractive index difference is 0.005. The function of the jacket is to protect the core.  

- Based on the mode number:
The inside of the cable can be classified into two different ways – Single-mode and multi-mode.

• Single mode fiber :- Single-mode fibers, on the other hand, are better used for longer communication distances, which are appropriate for the long-distance telephone as well as multi-channel TV transmission systems. Single-mode fibers have small core diameters of 5 or 10 μm. The diameter of the cladding in the multi-mode and single-mode fibers is 125 μm.

• Multi-mode fiber :- This type of fiber is applicable to short distance communications such as local area network systems and video surveillance. It has a very large core diameter of 50–62.5 μm. The large diameter of the core pushes the impulse to pass along different optical routes in random mode, hence, the rays move to touch the detector at dissimilar times. It causes temporary broadening of the signal, hindering data transmission speed and effective broadcast distance to about 200–500 m. 

 Application of Optical fiber:

The applications of the fiber optics field are still emerging (becoming apparent or prominent) and developing very fast, it is impossible to keep track each and every innovations and inventions. A Hydrogel optical fibers for continuous glucose monitoring are,Fiber optic probes are demonstrated for continuous glucose monitoring. A smartphone is exploited for detecting the probe's output signals.The optical technique simplifies the fabrication and readout of the fiber optic probes.The probe shows a high sensitivity in the physiological glucose range.Biocompatible hydrogel fiber probe enables implantable applications. The fabricated optical fiber sensors may have applications in wearable and implantable point-of-care and intensive-care continuous monitoring systems.

The future is not so distant when scientists and researchers will come up with more and more futuristic products and application using optical fibers.

How the Fiber optic assemblies deliver data through light pulse transmission?

Fiber optic assemblies consist of an optical fiber, a reinforcement strand for support, and fiber opticconnectors. While the copper wires mostly depend on electrical pulses to transmit data. Fiber optic assemblies systems rely on light pulse transmissions carried through the cable which delivers data at a quicker rate.

High sensitivity, low-cost fiber-optic anemometer have good resolutions and flow sensors. This also has the reflective-single mode and the multimode-single mode structure with no pressure drop. In air stream, inside a wind tunnel provides a reliable dynamic range from 4 to 10 m/s. Wavelength shifting sensitivity of 435.13 pm/(m/s) and resolution of 17.4 × 10−3 m/s. Output power intensity peak sensitivity of 2.62 dB/(m/s) on selected spectra peak.

Polyethanol glycol assisted gold nanodendrites (AuNDs) are synthesized by low-temperature sol-gel method. Uniform distribution of elements with smooth morphology is reported. Phenophthalein encapsulated AuNDs has refractive index 1.18 at 550 nm after. The Acidity of rainwater (pH 6) is determined by prepared sensor for validity purpose and practical applications. A fast response ~0.87 s, repeatability/reproducibility and linear response (R2 = 0.8912) are obtained at 440 nm.

Fabrication of fiber optic assemblies is done by theplasmonic sensor using ONLY chemical methods. Sensors utilize extraordinary transmission of light for signal transduction. Sensitivity of sensor is as high as in the case of sensors fabricated by sophisticated methods. Development of 3D printed flow cell is also underway. There is a successful determination of equilibrium dissociation binding constants (protein A/IgG).

In this process, a highly sensitive photocatalytic phenol optic-fiber sensor is developed. UV-vis-light-driven photocatalytic film for the detection of phenol is created. The working principle and sensitivity of proposed sensors are theoretically analyzed. Sensitivity, selectivity, pH immunity, and detection limit are checked. The proposed sensor shows high sensitivity and low detection limits.

Emergence and development of the LMR phenomenon as a fiber optic sensing platform are discussed. The concept and configuration of fiber optic LMR sensor with its performance parameters are briefed. Refractive index sensors utilizing various transparent semiconducting metal oxides and polymers supporting LMR are presented. Fiber-optic chemical and biosensors utilizing LMR principle are reviewed. Thepotential of LMR based bulk / nanostructured sensors are reviewed.