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Nguyễn Gia Hào

Academic year: 2023

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The MCF helps to facilitate the data transfer and the transfer of power in high power devices. The two spatial dimensions of mode and core are used in the design of optical fiber.

Key functional building blocks for next generation optical communication

  • Space division multiplexer/demultiplexer
  • Transceiver
  • Connectors
  • Amplifiers
  • Switches

For example, this could be the wavelength in WDM or the core in multi-core fiber optic transmission. To get around the limitation of spectrum contiguity, spectrum slots in the switch fabric can be swapped between different cores.

Limitation

Cross talk

Transmission is hindered by crosstalk in an MCF-based optical network, which can be reduced by power-mode coupling. It shows the average XT power due to other signals simultaneously propagating at the same wavelength in different MCF cores.

Non linearity

XPM is controlled by SPM as both depend on the refractive index and intensity of separate transmission pulses. Also in equation, the core multiplication factor [21] and the N number of core and D cladding diameters define Aeff(8). 9), the effective refractive index (cause of XPM) is also affected by the number of cores in the MCF.

Conclusion and future direction

Cariñe et al. "Multi-core fiber integrated multi-port beam splitters for quantum information processing." Crosstalk-Aware counter-propagating core assignment to reduce inter-core crosstalk and capacity waste in multi-core fiber optic networks.

TOP 1%

Introduction

  • Basics of light propagation in optical fibers
  • Light propagation in tapered optical fibers

Any sudden change in the dimensions or geometry of the fiber will provoke imminent light leaking from the core. Variation of the normalized frequency (V) and propagation constant (β) for different core radii corresponding to different taper ratios.

Fiber coating

Assuming an adiabatically tapered SMF with a waist radius of 5 μm with air as the surrounding medium, the expansion of the evanescent wave will yield a significant increase, as illustrated in Figure 4. This expression only holds for Ca < 1 because the fluid dynamics are different for larger values ​​of the capillary number. Given the nature of the fluids, an additional factor to consider for their use as fiber coatings is the Rayleigh-Plateau instability [31].

This effect leads to the decomposition of the uniform layer into a periodic array of points.

Coatings on tapered optical fibers

The fiber core and cladding radii are compared with the change of normalized frequency in Fig. 6d. Depending on the application, fiber coatings can be designed to optimize the interaction of the evanescent wave with the surrounding media. Effective refractive index at the waist portion of the fiber as a function of layer thickness for materials commonly used for conical coating and for sensing applications: PTFE [33], PBS [34], water [34], 1-propanol [35], isobutanol [35] and PDMS [26, 32].

Obviously, to have efficient and low-loss light propagation in the tapered fiber, the refractive index of the cladding material must be lower than the refractive index of the optical fiber.

Applications of coatings for devices

Otherwise it will cause losses as the light propagated in the cladding will never be connected back to the core.

Conclusions

This aspect depends on the physical dimensions, refractive indices of the materials and the wavelength being propagated. Finally, we discussed the propagation of light for different coating thicknesses with different materials in terms of the effect on the effective refractive index in the fiber band. A general thermal brush approach for precise band profile control in tapered fibers.” Optical Materials Express.

At the connection point in the basement of the building, the optical cable coming from outside is connected to a router or switch.

Distributed network structures

In the case of the TV cable network, one of these head-end stations is always necessary, because the signals from the satellite are converted and processed here for, among other things, cable reception. The reception technology in the cable networks has been fully converted to the digital standard since DOCSYS 3.1 [14] and is therefore on the same level as the telecommunication networks. This refers to the network areas that have been moved from the headends to the residential areas (FTTC fiber to the curb).

Distribution of the telecommunication transmission path by the provider through distribution of the board to the building and to the building to the dwellings.

Open building interconnection reference model - OBI

Here, it is assumed that the WAN connection provider terminates the VoIP traffic at the SIP registrar [21], which is integrated into the SoHo router. Configurations, implementations and functions in the area of ​​LAN to map functional regularity and quality of service for defined basic services (network access, VoIP, WLAN) are part of ongoing work. A test scenario specifically tailored to the SoHo environment was designed for the Bandwidth Priority VoIP survey.

The ITU standards for PESQ [24] and E-model [25] are used to objectively evaluate the speech quality of VoIP calls.

Network types in the building

  • POF fibers for inhouse applications
  • Optical properties and advantages of POF

Therefore, the SMF still plays a minor role in the field of short-term computing in buildings. Starting with simple transmission options for the consumer sector, such as digital connections between DVD players and pre-amplifiers in the home multimedia sector (TOSLINK [42] system) with data rates of a few Mb/s, the technology has now established itself in the automotive sector with the use of the MOST bus [43]. As a result, the cladding causes total reflection at the boundary layer and thus conducts the radiation into the core of the optical waveguide.

Usable connectors for glass fiber and polymer fibers in the home The optical polymer fiber POF has particularly good and simple properties for.

Usable connectors for glass fibers and polymeric fibers in the home The optical polymer fiber POF has particularly good and simple properties for

Another area for the introduction of RAF network technology is the construction and connection technology, e.g. The refractive index of the glue is 1.5 and the curing of the glue is realized by using a UV light lamp, which took only 3 minutes to cure (Figure 15). For the home sector, also known as domotics, an increasing demand for bandwidth is expected over the next few years.

Some of the ports of POF Ethernet switches even offer Power over Ethernet (PoE) functionality, so that IP telephones, IP cameras or WLAN access points with IEEE 802.11n data rates (up to 240 Mb/s net data rate [51]) can be operated on the POF network without plug-in power supply.

Example of an in-house network with optical POF fibers

For these areas, active components on the one hand, e.g., media converters for setting up dynamic network structures, and on the other hand, passive optical components such as splitters for the free construction of such networks are available in sufficient numbers for Ethernet applications up to 1000 Mb/s. On the user side, one or more ports with RJ-45 Base-Tx interface) are available for connecting end devices. Routing via additional switches, data can easily be sent to any room and connected.

By reducing radio energy, each room can connect to its own WiFi radio network and thus not disturb the transmission quality of neighboring rooms.

Conclusions

From this router, optical POF fiber cables are installed in all rooms in the house with four-port active switches and connected there. The radio energy must be set so low that the radio waves from the individual WiFi areas in the room do not enter the neighboring room and are sufficiently weakened by the walls. Both system components will experience further expansion stages in the range in the next few years and will therefore always remain applicable and expandable.

A selection of our books indexed in the Book Citation Index in the Web of Science™ Core Collection (BKCI).

Novel coded modulation technology based on probabilistic shaping 1 Principle of probabilistic shaping

  • Experiment

To evaluate the performance of the proposed scheme, an experiment is performed using the coherent optical communication system setup illustrated in Figure 3. The input power of the fiber is 0 dBm and the fiber is an SSMF with attenuation of α= 0.2 dB/. The successful transmission of the TCM-PS-16QAM signal means that our proposed new scheme is reasonable and achievable.

Probability distribution with the entropy of 2.8 bits/symbol of the proposed (a) subset S0 constellation, (b) TCM-PS-16QAM constellation at the receiver.

Impairment compensation techniques in coherent communication Coherent optical communication systems are implemented in the form of optical

  • Impairment compensation techniques at transmitter side
  • Impairment compensation techniques at receiver side

We then multiply the inverse of the estimated frequency response by the transmitted data in the frequency domain. LUT is a pre-compensation method used to compensate for the memory effect of the amplifier. The partial differential equation of the influence of fiber propagation on the signal envelope is derived and the transmission equation in the frequency domain can be obtained by Fourier transform.

It is widely used in digital signal processing module of coherent optical communication system.

Conclusion

Therefore, in this chapter we discuss the use of optical fiber tweezers for the assembly of live photonic probes. Live photonic probes can be assembled by capturing and assembling multiple cells using optical fiber tweezers. In this chapter, recent advances in OFTs in the trapping and manipulation of cells, particularly in the assembly of living photonic probes based on biological cells, were discussed.

These shaped living photonic probes offer a promising approach for biosensing in biological environments with high biocompatibility [12, 13].

Working principle of OFTs

It can be seen that the light emanating from the OFTs is first focused on the tip and then diverged into water with a divergence angle of 32°. It can be seen that, near the fiber tip, the force is negative, indicating a trapping force for particles. It can be seen that the trapping potential on the axis is smallest, and therefore particles can be trapped on the axis adjacent to the axis.

By simply moving the fiber probe, the trapped particles can be manipulated in a very flexible way.

Manipulation of single cell and multiple cells by OFTs

For particles close to the OFT tip, the dominated Fg can capture the particle up to the fiber tip. As the distance to the tip increases, Fs will become greater than Fg, and the dominated Fs will push the particle away from the fiber tip. The electric field amplitude (EA) distribution around the OFTs is shown in Figure 1b, with a laser beam at a wavelength of 980 nm launched into the fiber probe.

A laser at 980 nm wavelength was launched into the fiber probe, which was placed in a microfluidic channel with a flowing suspension of E. coli cells was captured and connected properly at the tip of the fiber probe.

Assembly of cell-based biophotonic waveguides by OFTs

Assembly of cell-based periodical structures by OFTs

Assembly of cell-based structures in vivo by OFTs

Assembly of living photonic probe by OFTs for bio-probing and detection

As an example, Figure 9 shows the use of a live photon probe in probing the localized fluorescence of leukemic cells in human blood [13]. Figure 9a–d show the ability of point excitation by manipulating a live photon probe to approach the cell membrane. Fiber optic tweezers for assembling living photonic probes DOI: http://dx.doi.org/10.5772/intechopen.98845.

Flexibility and deformability of the living photonic probe was also demonstrated through interaction with biospecimens.

Conclusions

As shown in Figure 9e and f, the living photonic probe was pressed against a leukemia cell, after which the living photonic probe was bent to an angle θ of 15° without puncturing the cell membrane. Due to its relatively large size and rigid structure, the fiber probe can easily be inserted into the cell (Figure 9h) and rupture the cell membrane (Figure 9i). In addition, the living photonic probes assembled using OFTs provide a biophotonic bridge between optical and biological worlds with natural materials.

With the advantages of its biocompatibility, the living photonic probes are expected to provide a new opportunity for direct sensing and detection of biological signal and information in biocompatible microenvironments.

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