D-Lightsys

**D-Lightsys**
Industry	Defence Space Telecommunication Transport
Founded	2002
Founder	Mathias Pez and François Quentel
Headquarters	Rosny-Sous-Bois, France
Owner	Radiall
Website	www.d-lightsys.com

D-Lightsys, a Radiall Company, designs and manufactures high performance optical interconnect solutions for severe environment applications. D-Lightsys products are based on optoelectronic components. Their transmitters are based on 850 nm Vertical Cavity Surface Emitting Lasers (VCSEL). The company headquarters are located in Rosny-Sous-Bois, near Paris, France. Products are manufactured in Isle d’Abeau, near Lyon, and are sold through the Radiall sales network under the D-Lightsys brand.

History

In 2002, D-Lightsys won the French award for the most innovative high-tech start-up. It was founded that year by Mathias Pez and François Quentel, two fiber optic interconnection specialists who previously worked for the Thales Group Advanced Research Center.

On April 15, 2005, Radiall announced its acquisition of a 40% stake in D-Lightsys, a company which specializes in electro-optical components for harsh environments.

On January 8, 2008, Radiall announced an increase in its shareholdings of the start-up D-Lightsys to 95 percent. This move is part of their strategy to reinforce their position as an innovative leader for electronic interconnection components. This integration will secure D-Lightsys financials and offer to their customers new guaranties with regards to their developments.

The combination of the two company's expertise will allow for the creation of an “Optical Center of Excellence” at Radiall Isle d’Abeau (near Lyon, France). This emergence of technology will enable Radiall to service the Aeronautic, Space and Defense markets with complete, end-to-end solutions that integrate Electrical/Optical signal conversion.

Research

Point to point VCSEL-based free space optical data link

D-Lightsys considers free space optical links for intermediate communication distances ranging from a few centimeters to one or two meters. In this paper,^[1] they present the initial simulations and the first experimental characterizations of a VCSEL-based point-to-point free space interconnect on distances ranging from 16 cm to 40 cm targeting bit rates up to 10 Gbit/s.

High-throughput optical interconnect technology

Alcatel Space and the CNES have investigated ^[2] optical interconnects as an enabling technology that may offer the high-throughput data communication capabilities required to the future on-board processors and digital equipment. D-Lightsys cooperated on this research with the development of the optoelectronic modules.

Spatiotemporal and thermal analysis of VCSEL

High-speed Optoelectronic Modules using Vertical Cavity Surface Emitting Lasers (VCSEL) coupled to Multi Mode Fibers (MMF) are a performing and low-cost solution for 10 Gigabit Ethernet (10 GbE) in short-distance optical links. A complete model of the spatiotemporal behavior of multimode VCSELs, through static and dynamic response, noise, thermal effects, and its coupling to MMF has been investigated. The two founders of D-Lightsys took part in this study.^[3]

Relative Intensity Noise shows modal dependence and can be affected by spatial filtering due to coupling and fiber propagation. Simulations permit to evaluate critical parameters, such as modulation formats, launching conditions, and operating temperature for global bandwidth and eye diagram optimization up to 10 Gbit/s. Simulation results are compared to measurements on prototype optoelectronic modules.

VHDL-AMS Model of a VCSEL Emission Module with Thermal Effects

In a 2004 study,^[4] in which Matthias Pez of D-Lightsys contributed, is presented a methodology based on VHDL-AMS modeling for taking into account the thermal effects of an optical emission module combined with electronic and optic behavior. The thermal transfer is due to the self-heating on one side and the interaction between the components of the other side. This methodology is implemented and simulated with ADVanceMS.