Birefringent and diffractive devices for implementing multi-Gbit/s transmission systems using visible WDM over SI-POF technology

Mención Internacional en el título de doctorNew optical devices are indispensable for the development of the future SI−POF high speed short−range communication networks and as well as in many sensors applications based on SI−POFs. These devices are not well established to date due to the physical and multimodal characteristics of the SI−POF technology as well as the characteristics of the SI−POF visible WDM systems. Therefore, the main objective that has been established for this research work is to develop new optical components based primarily on liquid crystals and diffractive elements for applications in advanced optical communication systems with plastic optical fibers, ensuring an optimized power consumption to reduce the carbon footprint of ICTs.Se necesitan nuevos dispositivos ópticos en el rango visible para el desarrollo de las futuras redes de comunicación de alta velocidad y corto alcance basadas en SI−POF. Estos dispositivos también son de gran utilidad en muchas aplicaciones de sensores basados en POF. Los diseños de estos dispositivos no están bien establecidos hasta la fecha debido a las características físicas y multimodales de la tecnología SI−POF, así como las características de los sistemas WDM en el visible. Por lo tanto, el principal objetivo que se ha establecido para este trabajo de investigación es el desarrollo de nuevos dispositivos ópticos basados principalmente en cristales líquidos y elementos de difracción para aplicaciones en sistemas avanzados de comunicaciones ópticas con fibras ópticas de plástico de salto de índice, lo que garantiza un consumo de energía optimizado para reducir la huella de carbono en esta tecnología en el sector TIC.Programa en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Rajeev J. Ram.- Vocal: Bruno Fracasso.- Secretario: Javier Mateo Gascó

Visible WDM System Design for Multi-Gbit/s Transmission over SI-POF

This proceeding at: SPIE Photonics West 2015. IX Conference Broadband Access Communication Technologies (SPIE).In order to increase the data rates of Multi-Gbit/s links based on large core step index (SI) plastic optical fibers (POF), different modulation scenes have been proposed. Another option is to use multiple optical carriers for parallel transmission of communication channels over the same fiber. Some designs to reach data rates of 14.77 Gb/s in 50 m, with 4 channels have been developed by off line processing. In this work, designs to test the potential of real Multi- Gbit/s transmission systems using commercial products are reported. Special care in designing low insertion loss multiplexers and demultiplexers is carried out to allow for greener solutions in terms of power consumption.This work has been sponsored by the Spanish institutions Ministerio de Economía y Competitividad under project TEC2012-37983-C03-02, Comunidad de Madrid under grant S2013/MIT-2790.Publicad

Efficient Multiplexer/Demultiplexer for Visible WDM Transmission over SI-POF Technology

A five channel step index plastic optical fiber proposal for a multiplexer/demultiplexer having insertion losses (IL) of 2.9-4 dB, pass bandwidths at -3 dB > 30 nm, crosstalk attenuation >30 dB and size of similar to ~65 mm x 55 mm, is demonstrated. It is based on a reflective diffraction grating with blazed profile and an aspheric lens. The theoretical analysis presented is used to further reduce the system size to similar to ~37 mm x 30 mm and to increase the number of channels to 8 keeping ILs < 4.5 dB. Experimental results have good agreement with theoretical expectations.This work was supported by the Spanish Ministry of Economy and by Madrid region under Grants TEC2012-37983-C03-02 and P2013/MIT-2790.Publicad

Visible WDM system for real-time multi-Gb/s bidirectional transmission over 50-m SI-POF

We report a 2 Gb/s bidirectional real-time data transmission with bit error rate (BER) < 1 x 10(-10) in a 50 m step-index polymer optical fiber link. The system is able to transmit 5 Gb/s using five channels. The system performance is tested using the most restrictive channels with the shortest and longest wavelengths in a real-time Ethernet link. The implementation takes an advantage of the PAM-16 modulation spectral efficiency and low loss multiplexers and demultiplexers, which provide an enhanced link power budget. The optical power per transmitted bit considering the BER implication for TCP/IP networks throughput is below 5.8 pJ/b. This is due to the low insertion losses <4 dB, in each five-channel multiplexer and demultiplexer.This work was supported in part by the Spanish Ministry of Economy under Grants TEC2012-37983-C03-02 and TEC2015-63826-C3-2-R, and in part by Madrid Region under Grant S2013/MIT-2790

Polymer Optical Fiber Temperature Sensor With Dual-Wavelength Compensation of Power Fluctuations

The design and development of a plastic optical fiber macrobend temperature sensor is presented. The sensor can operate in a temperature range from -55 to 70 degrees C and has a linear response versus temperature with a sensitivity of 8.95.10(-4) degrees C-1. The sensor system uses the ratio of transmittance at two wavelengths to implement a self-referencing technique in order to avoid undesirable power fluctuations influence. The transmittance ratio precision is 0.1%. An analysis has been developed to find the two wavelengths which ratio offers the highest linearity and sensitivity response. Experimental results are successfully compared with theoretical approaches.This work was supported by the Spanish Ministry of Economía y Competitividad and Madrid region under Grants TEC2012–37983-C03–02, P2013/MIT-2790.Publicad

Diffraction grating-based demultiplexers for SI-POF networks

The proceeding at: 22nd International Conference on Plastic Optical Fibers (POF 2013), took place in 2013 September,11-13, in Armação dos Buzios, Rio de Janeiro, (Brasil). The event Web site at: http://www.pof2013.org.br/ .In this paper, the possibility of implementing low-loss demultiplexer devices based on diffractive elements for SI-POF networks is studied. Theoretical and experimental analyses of three different diffractive setups are reported. It is also presented a 3-channel demultiplexer proposal, based on a transmission diffraction grating, with experimental insertion loss from 3.6dB to 5.8dB and adjacent channel crosstalk from −16.4dB to −28.6dB. This proposal presents low losses and low crosstalk, and it is very easy to implement in a compact reflective setup.This work has been sponsored by Ministerio de Economia y Competitividad (TEC2012-37983-C03-02) and Ministerio de Educacion, Cultura y Deportes (PRX12/00007),Publicad

Broadband 1x2 liquid crystal optical switch with low thermal dependence

The proceeding at: 22nd International Conference on Plastic Optical Fibers (POF 2013), took place in 2013 September,11-13, in Armação dos Buzios, Rio de Janeiro, (Brasil). The event Web site at: http://www.pof2013.org.br/ .In this work, the optimized design of a broadband 1×2 liquid crystal (LC) optical switch (OS) is presented. The design is based on a polarization rotator (PR), which is composed of two nematic LC cells. The azimuth angle and thickness of each LC cell is obtained with a simple computational optimization approach, with performance comparable with more complex existing procedures. The LC-OS is capable to route, in a uniform way, optical signals in the visible spectral range (400 nm - 700 nm) with low thermal dependence in the range from 15ºC to 40ºC, making it ideal for wavelength division multiplexing applications in POF systems.This work has been sponsored by the Spanish Economy and Education Ministries through grants (Ref. TEC2012-37983-C03-02 and Ref. PRX12/00007).Publicad

Dual-wavelength speckle-based SI-POF sensor for cost-effective detection of microvibrations

In this work, a novel method for cost-effective remote sensing of microvibrations is presented. The proposed technique detects periodical changes in the spatial distribution of energy on the speckle pattern at the endface of a SI-POF. By employing a dual-wavelength approach it is possible to increase the system sensitivity without changing its maximum mean squared error, which increases the system accuracy as well as its resolution. The system operates in reflective configuration providing a centralized interrogation scheme. The speckle pattern of both wavelengths is demultiplexed at the fiber end before being directly recorded by an off-the-shelf and a cost-effective webcam. The changes in the intensity distribution are processed at the remote interrogation unit. The proposed system is able to detect instantaneous and periodic microvibrations (with amplitudes ranging from 1 to 6 mu m) localized farther than 9 m from the remote interrogation unit.This work was supported in part by the Spanish Ministry of Economy and in part by the European Union Development Fund under grant TEC2015-63826-C3-2-R (MINECO/FEDER), and in part by the Comunidad de Madrid under grant S2013/MIT-2790

Design and analysis of a WDM System for Multi-Gbit/s Transmission over 50 m of SI-POF

Proceeding of: 23rd International Conference on Plastic Optical Fibers (POF 2014), 8-10 October 2014, Yokohama, JapanIn this work, the design of a data communication system based on a step−index plastic optical fiber link (SI−POF) and a 3 channel wavelength division multiplexing (WDM) scheme is presented. New proposals of multiplexer and demultiplexer devices are also presented. The multiplexer is able to combine 3 channels with insertion loss (IL) of about 1.4 dB. And the demultiplexer is a compact device based on a reflective diffraction grating that is able to separate 3 channels with IL < 4.5 dB and crosstalk < −30dB. The system has been experimentally analyzed using one of the 3 channels available (at 650 nm) and the early results are presented. These results show that the system can establish a real time link at 1 Gbit/s with 50 m of SI−POF and that it has the potential of expanding the transmission data rate up to 3 Gbit/s.This work has been sponsored by the Spanish Economy Ministry through grant (Ref.TEC2012-37983-C03-02)

Theoretical performance of the PF-GIPOF transfer function under different W-shaped refractive index profile designs

Proceeding of: 24th International Conference on Plastic Optical Fibers – ICPOF’15, Nuremberg (Germany), 22-24 September 2015The frequency response of PF-GIPOF with W-shaped refractive index profile is theoretically investigated. The proposed index profile incorporates a trench in the cladding region to tune the modal dispersion of outer groups.We focus on the effect of this design on the PF-GIPOF baseb and band width. The relationship between new index profiles and a high-bandwidth fiber condition is highlighted in order to increase the maximum achievable aggregated transmission capacity over PF-GIPOFs.This work was supported by the Spanish Ministry of Economia y Competitividad under grant TEC2012-37983-C03-02 and by the Comunidad de Madrid under grant S2013/MIT-2790