PhotoniX – Photonic Transmitters for Optical Networks and Interconnects in energy-efficient datacenters, supercomputers and homes, based on VCSELs

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PhotoniX (01.06.2015 – 30.09.2017)

Photonic Transmitters for Optical Networks and Interconnects in energy-efficient datacenters, supercomputers and homes, based on VCSELs

To match the demand of the productivity of modern computing systems, which is growing three orders of magnitude per decade, the single interconnect channel bit data rate should double each 2.5 years and the number of channels per link increase 5-fold each 10 years. Until recently copper was the dominant interconnect technology ($120 billion). At higher frequencies the electromagnetic losses and cross-talk are drastically enhanced, and new technologies are required. Since 2012 60 thousands energy-efficient optical links made of multimode fibers (MMF) powered by Vertical cavity surface-emitting lasers (VCSELs) are used in a single rack of supercomputer. Due to its small size, circular surface emission pattern, low operating current and a narrow spectrum VCSELs result a low cost, energy-efficient optical modules. Bit date rates up to 14Gb/s over 100m are reached by the industry. Scaling of the device to higher speeds is challenging as the modulation bandwidth is increasing as a square root of the drive current, while the degradation accelerates exponentially. At higher pulse frequencies the transmission distance rapidly decreases with pulse broadening.

The way to match the speed upgrade is to apply advanced nanotechnology concepts.
– Properly designed ultrathin strained narrow gap insertions as gain medium drastically enhances the modulation bandwidth at the same current;
– Introducing of strained barriers preventing the nonequilibrium carriers’ escape from the gain region allows further improvement of the modulation bandwidth and reliability;
– Optical design by oxide-confined aperture induced diffraction allows single mode operation extending the transmission length.

VI-Systems GmbH was first to pioneer and ship VCSELs transmitters up to 40Gb/s over 100m, far beyond the limits at that time. 54Gb/s OOK transmission significantly exceeding 1 km of multimode fiber is achieved with pilot devices. VIS will commercialize its novel interconnect technology and extend it up to 50Gb/s per channel.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 666866.

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Open access publications

Application of nanophotonics to the next generation of surface-emitting lasers
Nikolay N. Ledentsov, Nikolay Ledentsov Jr., Mikel Agustin, Joerg-R. Kropp, Vitaly A. Shchukin
Nanophotonics. 20160173, ISSN (Online) 2192-8614, ISSN (Print) 2192-8606, DOI:, February 2017

Novel trends and concepts in the design and fabrication of vertical cavity surface-emitting lasers (VCSELs) and their integration in optical networks and implementation in integrated photonics applications are discussed. To serve these goals and match the growing bandwidth demands, significant changes are to be implemented in the device design. New lateral leakage-mediated single-mode VCSELs, including both devices confined by oxide layers and those confined by alloy-intermixed regions, are likely to be good candidates for light sources for the data networks of the future. An overview of the records in VCSEL transmission distances and transmission speeds is discussed in this context.

Oxide-confined leaky vertical-cavity surface-emitting lasers for single-mode operation
Nikolay Ledentsov Jr., Vitaly Shchukin, Joerg Kropp, Mikel Agustin and Nikolay N. Ledentsov
1 August 2016, SPIE Newsroom. DOI: 10.1117/2.1201606.006544

Lateral photonic integration of oxide-confined leaky vertical-cavity surface-emitting lasers enable their application in data communication and sensing.

Events and presentations

PRESS RELEASE: Berlin, June 27, 2017

VI Systems launches 56G NRZ VCSEL driver and TIA chips

VI Systems offers the first generation of 56 Gbit/s laser driver and amplifier chips which are designed for Non-Return-to-Zero (NRZ) modulation in latency critical optical communication links.

VI Systems GmbH launches a set of VCSEL (vertical surface emitting laser) driver and limiting transimpedance amplifier (TIA) chip for 56 Gbit/s Non-Return-to-Zero (NRZ) modulation. The new generation of ICs are designed for differential signal input or output channels. The chips feature a low power consumption of less than 280 mW with a small die size of 0.64 x 1.04 mm.  The operation voltage is specified up to 3.3V.

The graphs shows the bandwidth simulation versus the actual measurement of the VCSEL driver IC at characteristic bias conditions. The -3dB modulation bandwidth is up to ~63 GHz.

The specification 56 Gbit/s NRZ for very short and ultra-short reach interconnects have recently be completed within the CEI-56G standard by the Optical Internet Working Forum (OIF).

Customer samples of the VCSEL driver and TIA chip are available now.

The developed was funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 666866.

VI Systems attended the FOE exhibtion in Japan with the support of the SME Instrument Overseas Trade Fair Participation program of the European Commission. The exhibition took place at the Big Sight exhibition grounds in Tokyo attracting a total of 67.615 visitors. The FOE is Asia’s leading show for optical communications. The latest equipment and technologies related to optical communications such as optical communication systems, devices, and optical fibers were presented from April 5-7, 2017.

VI Systems exhibts at the OFC 2017 exhibition from Mar 21 – 23, 2017. Visit VI Systems on the booth #3710

During the conference the following technical presentation is scheduled:
High Speed 160 Gb/s DMT VCSEL Transmission Using Pre-equalization,
Christoph Kottke, Christoph Caspar, Volker Jungnickel, Ronald Freund, Mikel Agustin, Nikolay Ledentsov

Photonics West 2017

VI Systems exhibited at the Photonics West 2017 in San Francisco, CA from  JAn 31 to Feb 2, 2107. During the conference the following technical paper have been presented:

Single-mode 850-nm vertical-cavity surface-emitting lasers with Zn-diffusion and oxide-relief apertures for > 50 Gbit/sec OOK and 4-PAM transmission (Invited Paper),
Jin-Wei Shi, Chia-Chien Wei, 
Jyehong Chen, Nikolay N. Ledentsov, Ying-Jay Yang
Proc. SPIE 10122, Vertical-Cavity Surface-Emitting Lasers XXI, 101220F (February 25, 2017); doi:10.1117/12.2256640

Resonant cavity light–emitting diodes based on dielectric passive cavity structures,
N. Ledentsov, Jr., V. A. Shchukin, J.-R. Kropp, L. Zschiedrich, Frank Schmidt, N. N. Ledentsov
Proc. SPIE 10124, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XXI, 101240O; doi:10.1117/12.2253089

Green, yellow and bright red (In,Ga,Al)P–GaP diode lasers grown on high–index GaAs substrates,
N. N. Ledentsov, V. A. Shchukin, Yu. M. Shernyakov, M. M. Kulagina, A. S. Payusov, N. Yu. Gordeev, M. V. Maximov, N. A. Cherkashin
Proc. SPIE. 10086, High-Power Diode Laser Technology XV, 100860L. (February 22, 2017) doi: 10.1117/12.2252957

Robustness versus thermal effects of single-mode operation of vertical-cavity surface-emitting lasers with engineered leakage of high-order transverse optical modes,
V. P. Kalosha, V. A. Shchukin, N. N. Ledentsov, Jr., J.-R. Kropp, N. N. Ledentsov
Proc. SPIE. 10122, Vertical-Cavity Surface-Emitting Lasers XXI, 101220K. (February 25, 2017) doi: 10.1117/12.2253021

Continuous wave and modulation performance of 1550nm band wafer-fused VCSELs with MBE-grown InP-based active region and GaAs-based DBRs,
A. V. Babichev, L. Y. Karachinsky, I. I. Novikov, A. G. Gladyshev, S. Mikhailov, V. Iakovlev, A. Sirbu, G. Stepniak, L. Chorchos, J. P. Turkiewicz, M. Agustin, N. N. Ledentsov, K. O. Voropaev, A. S. Ionov, A. Y. Egorov
Proc. SPIE 10122, Vertical-Cavity Surface-Emitting Lasers XXI, 1012208 (February 25, 2017); doi:10.1117/12.2250842

VI Systems attended the ECOC 2016 conference and exhibtion.  During the conference two technical presentation about the test results of VI Systems VCSEL were given:

Single Lane 150-Gb/s, 100-Gb/s and 70-Gb/s 4-PAM Transmission over 100-m, 300-m and 500-m MMF Using 25-G Class 850nm VCSEL
Tianjian Zuo, Liang Zhang, Jie Zhou, Qiang Zhang, Enbo Zhou, Gordon Ning Liu
Proceedings of ECOC 2016; 42nd European Conference on Optical Communication; ISBN: 978-3-8007-4274-5

112 Gb/s PAM-4 Optical Signal Transmission over 100-m OM4 Multimode Fiber for High-Capacity Data-Center Interconnects
Fotini Karinou, Nebojsa Stojanovic, Cristian Prodaniuc, Zhang Qiang, and Thomas Dippon
Proceedings of ECOC 2016; 42nd European Conference on Optical Communication; ISBN: 978-3-8007-4274-5

VI Systems attended in May 2016 the VCSEL day organized by the IEEE Photonics Society Sweden Chapter and the Fibre Optic Communications Research Centre (FORCE) at Chalmers University.

VI Systems attended the IFA as a visitor. At the IFA exhibition in Berlin several companies showed their 8K (7680 x 4320 pixel) TV protoypes. The data throughput for a compressed signal of 32 Gbit/s has been standardized in Displayport 1.4.

VI Systems attended the OFC 2016 conference & exhibition from March 22-23, 2016 in Anaheim, CA.

The company presented in their booth # 3763 a first 200 Gbit/s prototype of a 4 x 50 Gbit/s optical testboard for NRZ (non-return-to-zero modulation) or 4-PAM (pulsed amplitude modulation) which features for parallel optical channels over multi mode fiber.

optics testboard

Prototype of 4-channel parallel optics testboard for 4 x 50 Gbit/s transmission over 50/125 µm multimode ribbon fiber

PAM4 signal

Optical eye diagram of VCSEL at 50 Gbit/s 4-PAM

At the conference VI Systems presented one regular technical  paper:
54 Gbps OOK Transmission Using Single Mode VCSEL up to 1 km OM4 MMF
Grzegorz Stepniak, J.-R Kropp, N. N. Ledentsov, V. A. Shchukin, N. Ledentsov, G. Schaefer, and Jaroslaw P. Turkiewicz
OSA Technical Digest (online) (Optical Society of America, 2016), paper Th4D.5 DOI:

and one post-deadline paper in co-operation with two EU University partners:
107.5 Gb/s 850 nm multi- and single-mode VCSEL transmission over 10 and 100 m of multi-mode fiber
R. Puerta, M. Agustin, L. Chorchos, J. Tonski, J.-R. Kropp, N. Ledentsov Jr., V. A. Shchukin, N. N. Ledentsov, R. Henker, I. T. Monroy, J. J. Vegas Olmos, J. P. Turkiewicz
OSA Technical Digest (online) (Optical Society of America, 2016), paper Th5B.5

VI Systems attended Photonics West 2016. At the booth VIS presented for the first time the modeling and mapping services that the company now offers to it’s customers.

Following papers were published as part of the SPIE Proceedings Journals:

Close to 100 Gb/s Discrete Multitone Transmission over 100m of Multimode Fibre Using a Single Transverse Mode 850nm VCSEL
Bo Wu ; Xian Zhou ; Yanan Ma ; Jun Luo ; Kangping Zhong ; Shaofeng Qiu ; Zhiyong Feng ; Yazhi Luo ; Mikel Agustin ; Nikolay Ledentsov ; Joerg Kropp ; Vitaly Shchukin ; Nikolay N. Ledentsov ; Iain Eddie ; Lu Chao
Proc. SPIE 9766, Vertical-Cavity Surface-Emitting Lasers XX, 97660K (March 4, 2016); doi:10.1117/12.2208901

Direct Visualization of the In–Plane Leakageof High–Order Transverse Modes in VCSELs Mediated by Oxide–Aperture Engineering
N. Ledentsov Jr. ; V. A. Shchukin ; J.-R. Kropp ; S. Burger ; F. Schmidt ; N. N. Ledentsov
Proc. SPIE 9766, Vertical-Cavity Surface-Emitting Lasers XX, 976608 (March 4, 2016); doi:10.1117/12.2208909

Passive Cavity Surface–Emitting Lasers: Option of Temperature–Insensitive Lasing for Uncooled Dense Wavelength Division Multiplexing Systems
V. A. Shchukin ; N. N. Ledentsov ; T. Slight ; W. Meredith ; N. Y. Gordeev ; A. M. Nadtochy ; A. S. Payusov ; M. V. Maximov ; S. A. Blokhin ; A. A. Blokhin ; Yu. M. Zadiranov ; N. A. Maleev ; V. M. Ustinov ; K. D. Choquette
Proc. SPIE 9766, Vertical-Cavity Surface-Emitting Lasers XX, 976609 (March 4, 2016); doi:10.1117/12.2208915