| 1. |
- Estarán, Jose, et al.
(författare)
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140/180/204-Gbaud OOK Transceiver for Inter- and Intra-Data Center Connectivity
- 2019
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Ingår i: Journal of Lightwave Technology. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0733-8724 .- 1558-2213. ; 37:1, s. 178-187
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Tidskriftsartikel (refereegranskat)abstract
- We report on an on-off keying intensity-modulation and direct-detection C-band optical transceiver capable of addressing all datacenter interconnect environments at well-beyond 100Gbaud. For this, the transmitter makes use of two key InP technologies: a 2:1 double heterojunction bipolar transistor selector multiplexer and a monolithically integrated distributed-feedback laser traveling-wave electro-absorption modulator, both exceeding 100-GHz of 3-dB analog bandwidth. A pre-amplified 110-GHz PIN photodiode prior to a 100-GHz analog-to-digital converter complete the ultra-high bandwidth transceiver module; the device under study. In the experimental work, which discriminates between intra- and inter-data center scenarios (dispersion unmanaged 120, 560, 960m; and dispersion-managed 10, and 80km of standard singlemode fiber), we evaluate the bit-error rate evolution against the received optical power at 140, 180, and 204Gbaud on-off keying for different equalization configurations (adaptive linear filter with and without the help of short-memory sequence estimation) and forward error correction schemes (hard-decision codes with 7% and 20% overhead); drawing conclusions from the observed system-level limitations of the respective environments at this ultra-high baudrate, as well as from the operation margins and sensitivity metrics. From the demonstration, we highlight three results: successful operation with >6-dB sensitivity margin below the 7% error-correction at 140Gbaud over the entire 100m-80km range with only linear feed-forward equalization. Then the transmission of a 180Gbaud on-off-keying carrier over 80km considering 20% error-correction overhead. And finally, 10-km communication at 204Gbaud on-off keying with up to 6dB sensitivity margin, and regular 7%-overhead error-correction.
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| 2. |
- Hu, H., et al.
(författare)
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TuB4.1-chip based thz emitter for ultra-high speed THz wireless communication (Invited)
- 2019
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Ingår i: IEEE Photonics Society Summer Topical Meeting Series 2019, SUM 2019. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728105970
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Konferensbidrag (refereegranskat)abstract
- By using a monolithically integrated dual-distributed feedback (DFB) laser chip attached to a photomixing uni-Travelling carrier photodiode (UTC-PD) with a THz antenna, single-channel THz photonic-wireless transmission system with a net rate of 131 Gbit/s over a wireless distance of 10.7 m has been achieved.
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| 3. |
- Jia, S., et al.
(författare)
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Integrated Dual-DFB Laser for 408 GHz Carrier Generation Enabling 131 Gbit/s Wireless Transmission over 10.7 Meters
- 2019
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Ingår i: 2019 Optical Fiber Communications Conference and Exhibition, OFC 2019 - Proceedings. - Washington, D.C. : Institute of Electrical and Electronics Engineers Inc.. - 9781943580538
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Konferensbidrag (refereegranskat)abstract
- A monolithically integrated dual-DFB laser generates a 408 GHz carrier used for demonstrating a record-high single-channel bit rate of 131 Gbit/s transmitted over 10.7 m. 16-QAM-OFDM modulation and specific nonlinear equalization techniques are employed
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| 4. |
- Kerrebrouck, Joris Van, et al.
(författare)
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High-speed PAM4-based Optical SDM Interconnects with Directly Modulated Long-wavelength VCSEL
- 2019
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Ingår i: Journal of Lightwave Technology. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0733-8724 .- 1558-2213. ; 37:2, s. 356-362
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports the demonstration of high-speed PAM-4 transmission using a 1.5-μm single-mode vertical cavity surface emitting laser (SM-VCSEL) over multicore fiber with 7 cores over different distances. We have successfully generated up to 70 Gbaud 4-level pulse amplitude modulation (PAM-4) signals with a VCSEL in optical back-to-back, and transmitted 50 Gbaud PAM-4 signals over both 1-km dispersion-uncompensated and 10-km dispersion-compensated in each core, enabling a total data throughput of 700 Gbps over the 7-core fiber. Moreover, 56 Gbaud PAM-4 over 1-km has also been shown, whereby unfortunately not all cores provide the required 3.8 × 10$^-3$bit error rate (BER) for the 7% overhead-hard decision forward error correction (7% OH HDFEC). The limited bandwidth of the VCSEL and the adverse chromatic dispersion of the fiber are suppressed with pre-equalization based on accurate end-to-end channel characterizations. With a digital post-equalization, BER performance below the 7% OH-HDFEC limit is achieved over all cores. The demonstrated results show a great potential to realize high-capacity and compact short-reach optical interconnects for data centers.
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| 5. |
- Lin, Rui, 1988, et al.
(författare)
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Embedding quantum key distribution into optical telecom communication systems
- 2019
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Ingår i: International Conference on Transparent Optical Networks. - : IEEE Computer Society. - 9781728127798 ; 2019-July
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Konferensbidrag (refereegranskat)abstract
- Quantum key distribution (QKD) together with one-time pad cryptography provides unconditional security for the sensitive information. However, the lack of telecom compatibility hinders massive deployment of QKD. In this talk we will discuss the approaches of embedding QKD in optical communication systems and the recent progress.
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| 6. |
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| 7. |
- Ozolins, Oskars, et al.
(författare)
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Multilevel modulation at 100 gbaud for short reach C-band links
- 2019
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Ingår i: International Conference on Transparent Optical Networks. - : IEEE Computer Society. - 9781728127798
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Konferensbidrag (refereegranskat)abstract
- Datacenters experience an enormous traffic growth due to the vast amount of data to be stored, transmitted and processed [1]-[4]. Technical and economic challenges arise to keep up the bandwidth scalability. Therefore, cost-efficient short reach optical interconnects for 400 GbE intra-datacenter links are critical. Attractive solutions are proposed based on eight optical lanes thanks to compatibility with 100 GbE building blocks, where two optical lanes based 100 GbE solution is already being deployed [4]. Solutions for 400 GbE based on four optical lanes or even two optical lanes using high bandwidth components may be more attractive to reduce cost, power consumption and complexity of parallelism [5], [6]. In this talk, we report on several experimental demonstrations for short reach optical interconnects in C-band. We experimentally evaluate high-speed on-off keying (OOK) and 4-level pulse amplitude modulation (PAM4) and 8-level PAM8 transmitter performance in C-band for short reach optical interconnects. We demonstrate 100 Gbaud PAM4 transmission over 400 meters long standard single mode fiber without optical amplification. We also show results of numerical simulations showing achievable transmission reach in C-band for multilevel modulation at 100 Gbaud over standard single mode fiber with simple decision feedback equalizer. This paves the way for cost-effective short reach optical interconnects with multilevel modulation at 100 Gbaud and higher.
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| 8. |
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| 9. |
- Pang, Xiaodan, Dr., et al.
(författare)
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Key technologies to enable terabit-scale digital radio-over-fiber systems
- 2019
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9781510625327
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Konferensbidrag (refereegranskat)abstract
- With the approach of the 5G era, stringent requirements are imposed on the data transport solutions, including both of the supported transmission reach and the capacity. Radio-over-fiber technologies are considered to be promising candidates to cope with both aspects, owing to the low-loss and broad-bandwidth nature of the optical fibers. Meanwhile with such optical transport solutions, signals can be collected from the distributed remote radio sites and processed in a centralized manner. In this report, we target on the digital radio-over-fiber systems, and discuss about several key technologies, focusing on the aspects of coding and transmission, which could potentially enable terabit-scale data transport.
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| 10. |
- Udalcovs, Aleksejs, et al.
(författare)
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Towards 25+Gbpsλ IM-DD PON : NRZ, duobinary, PAM4, and DMT transmission and optical budget comparison
- 2019
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Ingår i: International Conference on Transparent Optical Networks. - : IEEE Computer Society. - 9781728127798
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Konferensbidrag (refereegranskat)abstract
- While infrastructure providers are expanding their portfolio to offer a sustainable solution for beyond 10 Gbps in optical access network segment, we compare experimentally several alternatives that may be used in future passive optical networks (PONs) to deliver 25+ Gbps net-rates. As promising candidates, we consider the intensity modulation direct detection (IM-DD) systems employing the following modulation formats: (i) duobinary, (ii) 4-level pulse amplitude modulation (PAM4), and (iii) discrete multitone (DMT), which are all more bandwidth efficient than the non-return-to-zero (NRZ) in current 10G PON solutions. In this paper, we focus on the optical budget after transmission over a 20 km single-mode fiber (SMF) link in C-band and discuss the intrinsic imperfections of optical components that may significantly reduce the received signal quality.
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