Fabrication of tunable chirped mPOF Bragg gratings using a uniform phase mask

"© 2018 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited"[EN] We demonstrate chirped Bragg gratings fabrication in doped microstructured tapered polymer fibers by using a uniform phase mask. The use of high photosensitive benzyl dimethyl ketal (BDK) doped core fiber allows to obtain chirped Bragg gratings by means of a single krypton fluoride laser pulse. The stability of the gratings has been confirmed and the strain and temperature sensitivity measurements demonstrate their tunable properties. Finally, different tapered profiles have been implemented in order to show the potentiality of this fabrication technique in polymer optical fibers. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.This work was supported by Fundação para a Ciência e Tecnologia (FCT)/MEC through national funds and when applicable co-funded by FEDER PT2020 partnership agreement under the project UID/EEA/50008/2013. C. A. F. Marques also acknowledges the financial support from FCT through the fellowship SFRH/BPD/109458/2015. The authors also acknowledge the Research Excellence Award Programme GVA PROMETEO 2017/103 FUTURE MICROWAVE PHOTONIC TECHNOLOGIES AND APPLICATIONS and Fundamental Research Funds for the Heilongjiang Provincial Universities (KJCXZD201703).Min, R.; Ortega Tamarit, B.; Marques, C. (2018). Fabrication of tunable chirped mPOF Bragg gratings using a uniform phase mask. Optics Express. 26(4):4411-4420. https://doi.org/10.1364/OE.26.004411S44114420264Hill, K. O., Takiguchi, K., Bilodeau, F., Malo, B., Kitagawa, T., Thériault, S., … Albert, J. (1994). Chirped in-fiber Bragg gratings for compensation of optical-fiber dispersion. Optics Letters, 19(17), 1314. doi:10.1364/ol.19.001314Ortega, B., Cruz, J. L., Capmany, J., Andres, M. V., & Pastor, D. (2000). Variable delay line for phased-array antenna based on a chirped fiber grating. IEEE Transactions on Microwave Theory and Techniques, 48(8), 1352-1360. doi:10.1109/22.859480Wang, C., & Yao, J. (2013). A Nonuniformly Spaced Microwave Photonic Filter Using a Spatially Discrete Chirped FBG. IEEE Photonics Technology Letters, 25(19), 1889-1892. doi:10.1109/lpt.2013.2279235Frazão, O., Melo, M., Marques, P. V. S., & Santos, J. L. (2005). Chirped Bragg grating fabricated in fused fibre taper for strain–temperature discrimination. Measurement Science and Technology, 16(4), 984-988. doi:10.1088/0957-0233/16/4/010Chang, H.-Y., Chang, Y.-C., Sheng, H.-J., Fu, M.-Y., Liu, W.-F., & Kashyap, R. (2016). An Ultra-Sensitive Liquid-Level Indicator Based on an Etched Chirped-Fiber Bragg Grating. IEEE Photonics Technology Letters, 28(3), 268-271. doi:10.1109/lpt.2015.2494611Lauzon, J., Thibault, S., Martin, J., & Ouellette, F. (1994). Implementation and characterization of fiber Bragg gratings linearly chirped by a temperature gradient. Optics Letters, 19(23), 2027. doi:10.1364/ol.19.002027Hill, P. C., & Eggleton, B. J. (1994). Strain gradient chirp of fibre Bragg gratings. Electronics Letters, 30(14), 1172-1174. doi:10.1049/el:19940772Kashyap, R., McKee, P. F., Williams, D. L., & Campbell, R. J. (1994). Novel method of producing all fibre photoinduced chirped gratings. Electronics Letters, 30(12), 996-998. doi:10.1049/el:19940669Cruz, J. L., Dong, L., Barcelos, S., & Reekie, L. (1996). Fiber Bragg gratings with various chirp profiles made in etched tapers. Applied Optics, 35(34), 6781. doi:10.1364/ao.35.006781Webb, D. J. (2015). Fibre Bragg grating sensors in polymer optical fibres. Measurement Science and Technology, 26(9), 092004. doi:10.1088/0957-0233/26/9/092004Marques, C. A. F., Webb, D. J., & Andre, P. (2017). Polymer optical fiber sensors in human life safety. Optical Fiber Technology, 36, 144-154. doi:10.1016/j.yofte.2017.03.010Tafur Monroy, I., vd Boom, H. P. A., Koonen, A. M. J., Khoe, G. D., Watanabe, Y., Koike, Y., & Ishigure, T. (2003). Data transmission over polymer optical fibers. Optical Fiber Technology, 9(3), 159-171. doi:10.1016/s1068-5200(03)00006-3Nespola, A., Abrate, S., Gaudino, R., Zerna, C., Offenbeck, B., & Weber, N. (2010). High-Speed Communications Over Polymer Optical Fibers for In-Building Cabling and Home Networking. IEEE Photonics Journal, 2(3), 347-358. doi:10.1109/jphot.2010.2048202Hu, X., Saez-Rodriguez, D., Marques, C., Bang, O., Webb, D. J., Mégret, P., & Caucheteur, C. (2015). Polarization effects in polymer FBGs: study and use for transverse force sensing. Optics Express, 23(4), 4581. doi:10.1364/oe.23.004581Hu, X., Pun, C.-F. J., Tam, H.-Y., Mégret, P., & Caucheteur, C. (2014). Tilted Bragg gratings in step-index polymer optical fiber. Optics Letters, 39(24), 6835. doi:10.1364/ol.39.006835Hongbo Liu, Huiyong Liu, Gangding Peng, & Whitbread, T. W. (2005). Tunable dispersion using linearly chirped polymer optical fiber Bragg gratings with fixed center wavelength. IEEE Photonics Technology Letters, 17(2), 411-413. doi:10.1109/lpt.2004.839378Marques, C. A. F., Antunes, P., Mergo, P., Webb, D. J., & Andre, P. (2017). Chirped Bragg Gratings in PMMA Step-Index Polymer Optical Fiber. IEEE Photonics Technology Letters, 29(6), 500-503. doi:10.1109/lpt.2017.2662219Sáez-Rodríguez, D., Nielsen, K., Rasmussen, H. K., Bang, O., & Webb, D. J. (2013). Highly photosensitive polymethyl methacrylate microstructured polymer optical fiber with doped core. Optics Letters, 38(19), 3769. doi:10.1364/ol.38.003769Hu, X., Woyessa, G., Kinet, D., Janting, J., Nielsen, K., Bang, O., & Caucheteur, C. (2017). BDK-doped core microstructured PMMA optical fiber for effective Bragg grating photo-inscription. Optics Letters, 42(11), 2209. doi:10.1364/ol.42.002209Pospori, A., Marques, C. A. F., Bang, O., Webb, D. J., & André, P. (2017). Polymer optical fiber Bragg grating inscription with a single UV laser pulse. Optics Express, 25(8), 9028. doi:10.1364/oe.25.009028Marques, C., Pospori, A., Demirci, G., Çetinkaya, O., Gawdzik, B., Antunes, P., … Webb, D. (2017). Fast Bragg Grating Inscription in PMMA Polymer Optical Fibres: Impact of Thermal Pre-Treatment of Preforms. Sensors, 17(4), 891. doi:10.3390/s17040891Saez-Rodriguez, D., Min, R., Ortega, B., Nielsen, K., & Webb, D. J. (2016). Passive and Portable Polymer Optical Fiber Cleaver. IEEE Photonics Technology Letters, 28(24), 2834-2837. doi:10.1109/lpt.2016.2623419Bhowmik, K., Peng, G.-D., Luo, Y., Ambikairajah, E., Lovric, V., Walsh, W. R., & Rajan, G. (2016). Etching Process Related Changes and Effects on Solid-Core Single-Mode Polymer Optical Fiber Grating. IEEE Photonics Journal, 8(1), 1-9. doi:10.1109/jphot.2016.2524210Bhowmik, K., Gang-Ding Peng, Ambikairajah, E., Lovric, V., Walsh, W. R., Prusty, B. G., & Rajan, G. (2015). Intrinsic High-Sensitivity Sensors Based on Etched Single-Mode Polymer Optical Fibers. IEEE Photonics Technology Letters, 27(6), 604-607. doi:10.1109/lpt.2014.2385875Dong, L., Cruz, J. L., Reekie, L., & Tucknott, J. A. (1995). Fabrication of chirped fibre gratings using etched tapers. Electronics Letters, 31(11), 908-909. doi:10.1049/el:19950588Putnam, M. A., Williams, G. M., & Friebele, E. J. (1995). Fabrication of tapered, strain-gradent chirped fibre Bragg gratings. Electronics Letters, 31(4), 309-310. doi:10.1049/el:1995017

On the Conditions that Justify Dynamic Reconfigurability in WDM-TDMA Optical Access Networks

[EN] In a passive optical network with a hybrid wavelength division multiplexing time division multiple-access scheme, implementing reconfigurable wavelength assignment is complex; hence the need to determine the conditions for which the capacity improvements justify requiring reconfigurability over adopting a more inexpensive fixed wavelength assignment. Fixed and reconfigurable approaches to wavelength assignment are modeled and evaluated under nonstationary traffic conditions. The performance improvement is obtained in terms of bit rate gain relative to the nominal bandwidth and depends on the number of wavelength channels as well as the magnitude of the load offered by the optical network units. In addition, frame delay and frame loss in relation to the bit rate performance are obtained for Pareto and exponentially distributed traffic. Simulations show that when introducing reconfigurability, typical peak bit rate gains with respect to the fixed case are 17%, and maxima of 175% are potentially possible when traffic demands are particularly uneven.This work was supported by the EC 7th Framework Program: Architectures for fLexible Photonic Home and Access networks (ALPHA), under contract ICT CP-IP 212 352, from the Generalitat of Valencia under contract ACOMP/2010/196. The authors thank the Performability Engineering Research Group (PERFORM) at the University of Illinois at Urbana-Champaign for developing the software tool Mobius.García Roger, D.; Artundo Martínez, I.; Ortega Tamarit, B. (2011). On the Conditions that Justify Dynamic Reconfigurability in WDM-TDMA Optical Access Networks. Journal of Optical Communications and Networking. 3(4):259-271. https://doi.org/10.1364/JOCN.3.000259S25927134A highly flexible and efficient passive optical network employing dynamic wavelength allocation. (2005). Journal of Lightwave Technology, 23(1), 277-286. doi:10.1109/jlt.2004.838811Maier, M., Herzog, M., & Reisslein, M. (2007). STARGATE: the next evolutionary step toward unleashing the potential of WDM EPONs [Topics in Optical Communications]. IEEE Communications Magazine, 45(5), 50-56. doi:10.1109/mcom.2007.358848Urban, P. J., Huiszoon, B., Roy, R., de Laat, M. M., Huijskens, F. M., Klein, E. J., … de Waardt, H. (2009). High-Bit-Rate Dynamically Reconfigurable WDM–TDM Access Network. Journal of Optical Communications and Networking, 1(2), A143. doi:10.1364/jocn.1.00a143Glatty, R., Guignard, P., & Chanclou, P. (2009). Fair Resource Distribution Within the Flexible WDMA/TDMA Optical Access Network Based on GPON Infrastructure. Journal of Optical Communications and Networking, 1(2), A17. doi:10.1364/jocn.1.000a17Roy, R., Manhoudt, G., & van Etten, W. (2008). Optical-router-based dynamically reconfigurable photonic access network. Journal of Optical Networking, 8(1), 51. doi:10.1364/jon.8.000051Koonen, T., Steenbergen, K., Janssen, F., & Wellen, J. (2001). Photonic Network Communications, 3(3), 297-306. doi:10.1023/a:1011411600793Homa, J., & Bala, K. (2008). ROADM Architectures and Their Enabling WSS Technology. IEEE Communications Magazine, 46(7), 150-154. doi:10.1109/mcom.2008.4557058Strasser, T., & Taylor, J. (2008). ROADMS Unlock the Edge of the Network. IEEE Communications Magazine, 46(7), 146-149. doi:10.1109/mcom.2008.4557057Leland, W. E., Taqqu, M. S., Willinger, W., & Wilson, D. V. (1994). On the self-similar nature of Ethernet traffic (extended version). IEEE/ACM Transactions on Networking, 2(1), 1-15. doi:10.1109/90.282603Kramer, G., Mukherjee, B., & Pesavento, G. (2002). Photonic Network Communications, 4(1), 89-107. doi:10.1023/a:1012959023043Skubic, B., Jiajia Chen, Ahmed, J., Wosinska, L., & Mukherjee, B. (2009). A comparison of dynamic bandwidth allocation for EPON, GPON, and next-generation TDM PON. IEEE Communications Magazine, 47(3), S40-S48. doi:10.1109/mcom.2009.4804388Papadimitriou, G. I., & Pomportsis, A. S. (1999). Self-adaptive TDMA protocols for WDM star networks: a learning-automata-based approach. IEEE Photonics Technology Letters, 11(10), 1322-1324. doi:10.1109/68.789731Linardakis, C., Leligou, H. C., Stavdas, A., & Angelopoulos, J. D. (2005). Using explicit reservations to arbitrate access to a metropolitan system of slotted interconnected rings combining TDMA and WDMA. Journal of Lightwave Technology, 23(4), 1576-1585. doi:10.1109/jlt.2005.844198Kanonakis, K., & Tomkos, I. (2010). Improving the efficiency of online upstream scheduling and wavelength assignment in hybrid WDM/TDMA EPON networks. IEEE Journal on Selected Areas in Communications, 28(6), 838-848. doi:10.1109/jsac.2010.100809McGarry, M. P., Reisslein, M., & Maier, M. (2006). WDM Ethernet passive optical networks. IEEE Communications Magazine, 44(2), 15-22. doi:10.1109/mcom.2006.1593545Dhaini, A. R., Assi, C. M., Maier, M., & Shami, A. (2007). Dynamic Wavelength and Bandwidth Allocation in Hybrid TDM/WDM EPON Networks. Journal of Lightwave Technology, 25(1), 277-286. doi:10.1109/jlt.2006.886683Chihchung Chen, Chengkuo Lee, & Yen-Jyh Lai. (2003). Novel voa using in-plane reflective micromirror and off-axis light attenuation. IEEE Communications Magazine, 41(8), S16-S20. doi:10.1109/mcom.2003.122271

Optical CS-DSB Schemes for 5G mmW Fronthaul Seamless Transmission

[EN] This paper describes the experimental demonstration of the hybrid optical/millimeter wave signal generation and transmission over combined optical fiber and free space optics fronthaul network with a seamless antenna link. An electrical bandpass filter is used to filter out the spectrum after photodetection in order to realize the seamless antenna transmission. The successful transmission of 64/256-quadrature amplitude modulation (QAM) 5G signal with up to 200 MHz bandwidth is presented by using two different setups: one is based on two Mach-Zehnder modulators (MZM) and the other employs a directly modulated laser (DML) to provide more cost efficient fronthaul solution. The DML based approach reveals mildly better performance in comparison to the MZMs in terms of higher achieved signal-to-noise ratio and lower error vector magnitude (EVM). More specifically, the best signal-to-noise ratio and EVM achieved with the DML based setup has been 31.5 dB and 3. 3%, respectively, compared to 30.3 dB and 3.8% with the MZMs based setup while transmitting 256-QAM signal with 100 MHz bandwidth. However, both setups kept the EVM well below the given 9% and 4.5% limit for 64- and 256-QAM, respectively.This work was supported in part by the Ministry of Industry and Trade in Czech Republic under Grant FV40089, in part by EU COST Action NEWFOCUS under Grant CA19111, and in part by the Ministerio de Ciencia, Innovacion y Universidades under Grant FOCAL RTI2018-101658-B-I00.Bohata, J.; Vallejo-Castro, L.; Ortega Tamarit, B.; Zvanovec, S. (2022). Optical CS-DSB Schemes for 5G mmW Fronthaul Seamless Transmission. IEEE Photonics Journal. 14(2):1-7. https://doi.org/10.1109/JPHOT.2022.31610871714

Hybrid POF/VLC Links Based on a Single LED for Indoor Communications

[EN] A hybrid fiber/wireless link based on a single visible LED and free of opto-electronic intermediate conversion stages has been demonstrated for indoor communications. This paper shows the main guidelines for proper coupling in fiber/air/detector interfaces. Experimental demonstration has validated the design results with very good agreement between geometrical optics simulation and received optical power measurements. Different signal bandwidths and modulation formats, i.e., QPSK, 16-QAM, and 64-QAM, have been transmitted over 1.5 m polymer optical fiber (POF) and 1.5 m free-space optics (FSO). Throughputs up to 294 Mb/s using a 64-QAM signal have been demonstrated using a commercial LED, which paves the way for massive deployment in industrial applicationsThis work was supported by the Spanish Ministerio de Ciencia, Innovacion y Universidades RTI2018-101658-B-I00 FOCAL project.Apolo-Gonzaga, JA.; Ortega Tamarit, B.; Almenar Terre, V. (2021). Hybrid POF/VLC Links Based on a Single LED for Indoor Communications. Photonics. 8(7):1-12. https://doi.org/10.3390/photonics80702541128

Fast inscription of long period gratings in microstructured polymer optical fibers

"© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works."[EN] We demonstrate 20 dB long period grating (LPG) fast inscription in microstructured polymer optical fibers (mPOFs) using a point-by-point technique obtaining an LPG total length of 25 mm. Two 248 nm UV laser pulses of 15 ns duration have been employed for every inscription point, which means a time reduction by over 21 times compared with the fastest inscription time already reported in literature. The device has been fabricated in a single-mode mPOF with a core that has been doped with benzyl dimethyl ketal for photosensitivity enhancement. Moreover, we characterize the strain and temperature responses and the stability of the fabricated gratings response under different conditions in order to assess the viability for different applications.This work was supported in part by the Fundacao para a Ciencia e Tecnologia/MEC through national funds, in part by FEDER-PT2020 partnership agreement under the Projects UID/EEA/50008/2013, in part by the Research Excellence Award Programme GVA PROMETEO 2017/103 Future Microwave Photonic Technologies and Applications and Fundamental Research Funds for the Heilongjiang Provincial Universities under Grant KJCXZD201703. The work of C. Marques was supported by the FCT through the Fellowship under Grant SFRH/BPD/109458/2015.Min, R.; Marques, C.; Nielsen, K.; Bang, O.; Ortega Tamarit, B. (2018). Fast inscription of long period gratings in microstructured polymer optical fibers. IEEE Sensors Journal. 18(5):1919-1923. https://doi.org/10.1109/JSEN.2018.2791663S1919192318

Bragg Grating Inscription With Low Pulse Energy in Doped Microstructured Polymer Optical Fibers

[EN] We demonstrate that fiber Bragg gratings (FBGs) can be written in a doped polymer optical fiber (POF) in a low ultraviolet (UV) pulse energy regime (60 ¿J/pulse) using a 248-nm krypton fluoride excimer laser system. The total energy density per inscription necessary to obtain Bragg gratings is between 493.6 and 3825 mJ/cm2, depending on the number of pulses and the pulse energy. The impact of the pulse energy on the growth of the Bragg grating is investigated, and it is shown that the 248-nm light induces a positive refractive index change. This article demonstrates that the FBGs can be obtained in the POFs without high pulse energy (mJ level) at 248-nm wavelength, which reduces maintenance costs. Furthermore, we can consider it as a solution to increase the lifetime of the laser system without high energy still allowing fast and efficient production of the FBGs for sensing applications.This work was supported in part by the UID/EEA/50008/2013; in part by the SFRH/BPD/109458/2015; in part by the KJCXZD201703; and in part by the GVA PROMETEO2017/103.Min, R.; Ortega Tamarit, B.; Nielsen, K.; Bang, O.; Marques, C. (2018). Bragg Grating Inscription With Low Pulse Energy in Doped Microstructured Polymer Optical Fibers. IEEE Sensors Letters. 2(2):1-4. https://doi.org/10.1109/LSENS.2018.2830804S142

Passive and Portable Polymer Optical Fiber Cleaver

"(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works."Polymer optical fiber (POF) is a growing technology in short distance telecommunication due to its flexibility, easy connectorization, and lower cost than the mostly deployed silica optical fiber technology. Microstructured POFs (mPOFs) have particular promising potential applications in the sensors and telecommunications field, and they could specially help to reduce losses in polymer fibers by using hollow-core fibers or reduce the modal dispersion by providing a large mode area endlessly single-mode. However, mPOFs are intrinsically more difficult to cut due to the cladding hole structure and it becomes necessary to have a high quality POF cleaver. In the well-known hot-blade cutting process, fiber and blade are heated, which requires electrical components and increases cost. A new method has recently been identified, allowing POF to be cut without the need for heating the blade and fiber, thus opening up the possibility of an electrically passive cleaver. In this letter, we describe the implementation and testing of a high quality cleaver based on a mechanical system formed by a constant force spring and a damper, which leads to the first reported electrical passive and portable cleaver.This work was supported in part by the Juan de la Cierva Program of the Spanish Government, in part by the National Project MINECO under Grant TEC2014-60378-C2-1-R MEMES, in part by the Regional GVA funded PROMETEO 2013/012 Project on Next Generation Microwave Photonic Technologies, and in part by the China Scholarship Council.D. Sáez-Rodriguez; Min, R.; Ortega Tamarit, B.; Nielsen, K.; Webb, D. (2016). Passive and Portable Polymer Optical Fiber Cleaver. IEEE Photonics Technology Letters. 28(24):2834-2837. doi:10.1109/LPT.2016.262341928342837282

M-QAM signal transmission at the photonically generated K-band over thermal-induced turbulent FSO links with different turbulence distributions

[EN] We present a theoretical and experimental study on the impact of different thermal-induced free-space turbulence distributions on the M-quadrature amplitude modulation (M-QAM) signal transmission in radio frequency K-band over hybrid optical links of standard single mode fiber (SSMF) and free-space optics (FSO). Frequency multiplication using an external intensity modulator biased at the null transmission point has been employed to photonically generate radio signals at a frequency of 25 GHz, included for the frequency bands for fifth-generation (5G) mobile networks. Moreover, extensive simulations have been performed for 10 Gb/s with 4-, 16-, and 64-QAM over 5 km of SSMF and 500 m long FSO channels under scenarios with different turbulence levels and distributions. Proof-of-concept experiments have been conducted for 20 MHz with 4- and 64-QAM over 5 km of SSMF and 2 m long FSO channels under turbulence conditions. Both theoretical and experimental systems have been analyzed in terms of error vector magnitude (EVM) performance showing feasible transmission over the hybrid links in the received optical power range. Non-uniform turbulence distributions are shown to have a different impact on M-QAM modulation formats, i.e., turbulence distributions with higher strength in the middle of the FSO link reveal a 1.9 dB penalty when using 64-QAM signals compared to a 1.3 dB penalty using 4-QAM signals, whereas higher penalties have been measured when 4-QAM format is transmitted over turbulence distributions with larger magnitude in the second half of the FSO link. The results have been validated by theoretical predictions and lead to practical consequences on future networks' deployment.Generalitat Valenciana (PROMETEO 2017/103); Ministerio de Ciencia, Innovacion y Universidades (FOCAL RTI2018-101658-B-I00); Ministerstvo Prumyslu a Obchodu (FV30427) and within European Cooperation in Science andTechnology (CA16220).Vallejo-Castro, L.; Nguyen, D.; Bohata, J.; Ortega Tamarit, B.; Zvanovec, S. (2020). M-QAM signal transmission at the photonically generated K-band over thermal-induced turbulent FSO links with different turbulence distributions. Applied Optics. 59(16):4997-5005. https://doi.org/10.1364/AO.390103S499750055916Zhang, R., Lu, F., Xu, M., Liu, S., Peng, P.-C., Shen, S., … Chang, G.-K. (2018). An Ultra-Reliable MMW/FSO A-RoF System Based on Coordinated Mapping and Combining Technique for 5G and Beyond Mobile Fronthaul. Journal of Lightwave Technology, 36(20), 4952-4959. doi:10.1109/jlt.2018.2866767Lee, C. H. (Ed.). (2017). 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A Novel Radio-Over-Fiber System Based on Carrier Suppressed Frequency Eightfold Millimeter Wave Generation. IEEE Photonics Journal, 9(5), 1-6. doi:10.1109/jphot.2017.2731620Khalighi, M. A., & Uysal, M. (2014). Survey on Free Space Optical Communication: A Communication Theory Perspective. IEEE Communications Surveys & Tutorials, 16(4), 2231-2258. doi:10.1109/comst.2014.2329501Bloom, S., Korevaar, E., Schuster, J., & Willebrand, H. (2003). Understanding the performance of free-space optics [Invited]. Journal of Optical Networking, 2(6), 178. doi:10.1364/jon.2.000178Anderson, H. R. (2003). Fixed Broadband Wireless System Design. doi:10.1002/0470861290Ghassemlooy, Z., Popoola, W., & Rajbhandari, S. (2019). Optical Wireless Communications. doi:10.1201/9781315151724Borah, D. K., & Voelz, D. G. (2009). Pointing Error Effects on Free-Space Optical Communication Links in the Presence of Atmospheric Turbulence. 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OOFDM signal transmission using a single optical broadband source

[EN] In this letter, optical OFDM signal transmission is demonstrated by using a broadband optical source over a 10 km fiber link. OFDM signal transmission usually employs lasers to generate the optical carrier since the chromatic fiber dispersion prevents the use of broadband optical sources. However, an interferometric system is introduced to allow signal transmission at a given RF band when a broadband optical source is employed. Optical sources with different optical bandwidths have been employed to explore the limitations of the system. OFDM transmission at 2 Gb/s using both QPSK and 16QAM modulation is demonstrated over 10 km.This work was supported in part by the National Project MINECO under Grant TEC2014-60378-C2-1-R MEMES and in part the Regional GVA funded Prometeo 2013/012 Project on Next Generation Microwave Photonic technologies.Chicharro López, FI.; Ortega Tamarit, B.; Diego Antón, MD.; Mora Almerich, J. (2017). OOFDM signal transmission using a single optical broadband source. IEEE Photonics Technology Letters. 29(7):563-566. https://doi.org/10.1109/LPT.2017.2668464S56356629

OFDM-IDMA for Uplink Transmission in Passive Optical Networks

In this paper, we propose the orthogonal frequency-division multiplexing-interleaved division multiplexing access (OFDM-IDMA) technique for passive optical networks (PONs). We evaluate the performance of such systems and compare it with the already proposed OFDM-Access (OFDMA) technique by means of the bit error rate versus received power for two different coding schemes and different number of iterations. Results show that OFDM-IDMA technique with an unequal power allocation distribution among the different optical network units (ONUs) offers similar performance to OFDMA when used with a simple convolutional code at an aggregated rate of 4 and 8 Gbits/s. Dynamic bandwidth allocation can be easily implemented with this technique. © 2011 IEEE.Sánchez Costa, C.; Ortega Tamarit, B.; Capmany Francoy, J. (2012). OFDM-IDMA for Uplink Transmission in Passive Optical Networks. IEEE Photonics Journal. 4(1):1-13. doi:10.1109/JPHOT.2011.2177450S1134