LESSENGERS: The Right Wiring for Datacenters

Chongcook Kim, Founder, and CEO, LESSENGERSChongcook Kim, Founder, and CEO
The exponential rise of optical interconnects, succeeding their electrical counterparts, has led to a drastic surge in internet traffic and the consequential balancing act played out by data center solution providers in attaining desired performance and cost levels. While the significance and cost portion of data center interconnects (DCI) continue to increase, optical connection alignment by joining multiple lenses is easier said than done. From a technical aspect, the problem in optical coupling is the decreasing dimension of optical ports and increasing number of channels and interfaces that govern internet data traffic.

Soaring above and beyond these optical coupling challenges, fiber optic solutions and services specialist, LESSENGERS Inc.’s (“LESSENGERS”) unique direct optical wiring (DOW) technology is an excellent conduit to resolve three key objectives of low cost, small size, and lower power consumption in the data center interconnects.



“Many of the challenges in the photonics space, specifically in the optical interconnects, originate from interfaces where the conventional electronics and photonics technologies meet to create highperformance optical signal transmissions,” says Chongcook Kim, founder, and CEO at LESSENGERS.

The DOW will be a promising solution to the migration toward the pulse amplitude modulation 4-level (PAM4)- based era of 800G/1.6T. LESSENGERS’ DOW-based optical coupling technology can eliminate pain points such as optical reflection, channel-to-channel crosstalk, or scattering that are inevitable in lens optics-based optical interconnects, by individually and seamlessly locking components into place.

The difficulty in lens-based optical alignment results in the growing demand for high-performance and costly optical coupling mechanism to overcome such challenges, preventing the increase in the number of optical channels. On the other hand, the DOW is well-poised to allow optical alignment of 8, 16, 32, 64 channels, or above. Designed with less than a millimeter dimension connection and no active alignment approach, LESSENGERS avoids multichannel lens assembly to ensure near-zero optical crosstalk.
Little to no air gap between optical ports also assures minimal reflection noise. These advantages will reflect more prominently as data signals become complex, transmission capacity increases, and emitter and receiver window sizes of optical chips become smaller.

Perfect for simple and highly integrated data center structures, the DOW uses polymer wires, very similar to metal wires in electronics, as a substitute for the commonly used lens optics. An arch-shaped polymer wire is drawn from end to end between components, and LESSENGERS’ patent technology automatically builds the wire from a polymer solution that solidifies in the air during wiring.

Many of the challenges in the photonics space, specifically in the optical interconnects, originate from interfaces, where the conventional electronics and photonics meet to create highperformance optical signal transmissions

As temperature conditions are key factors affecting interconnectivity stability, polymer wire offers more thermal resistance and sustenance from cold (-77°C) and hot (250°C) extremes. This flexibility makes it less vulnerable to mechanical or thermal stress.

“The environmental and mechanical performance of LESSENGERS’ DOW-based optical interconnects is excellent and surpasses the specified reliability performance requirements in the industry,” says Kim.

In the applicatory phase, component wiring is automated based on pattern recognition that adjusts efficiently to variations in the position of parts that form a transceiver. Applicable for single-mode and multi-mode system configurations, the optical signal path of polymer wire can be easily controlled anywhere between 100 nm to 100 μm.

Working alongside the Consortium for On-Board Optics (COBO), the high integration capabilities of the DOW technology are valued in the creation of an ultra-small optical module required for a multi-mode waveguide interconnect system (MWIS). The 56G signaling-based optical module comprises a 4-channel transmitter and 4-channel receiver, with an aggregate data rate of 224 Gbps and a small footprint of 10 × 30 mm2. LESSENGERS’ ultra-small sized optical module with an additional great degree of freedom to optical waveguides will enable efficient and effective replacement of the traditional long electrical traces to deliver and receive information at faster speeds with minimum energy. The DOW technology and non-requirement of active optical alignment also allow smaller module sizes, taking up less floor space than conventional coupling technologies.
To unleash higher power efficiency and faster transfer rates, the fiber optics interconnectivity solution and services provider is currently working on 112G signaling-based optical interconnects. “Once the upgrade is done on our existing module, a new module with the maximum aggregate data rate of 448 Gbps can be achieved,” adds Kim. As multiple components come into play in an optical interconnect, LESSENGERS will further develop these applicatory techniques in improving photonic integrated circuits for multiple optical links to interact more freely within a single board.
  • The environmental and mechanical performance of LESSENGERS’ DOW-based optical interconnects is excellent and surpasses the specified reliability performance requirements in the industry


As optical interconnect technologies become more critical to enterprise operations, LESSENGERS will create a balance between high performance and low cost. To make the solution a standard technology in the photonics space, the company is also set to start customer sampling of 800G optical transceivers such as 800G QSFP-DD or OSFP optical transceivers and active optical cables. With datacenter optical interconnects costing enterprises a fortune in implementation charges, LESSENGERS will promote cost-effective next-generation optical interconnects and act as an enabler in 800G and 1.6T integrated optical engines and modules. Enabling small and mid-sized companies to ride the data center wave with ease, LESSENGERS’ transceivers and cables will provide the best cost-effectiveness with better performance.

To advance the future of optical interconnects coupling, LESSENGERS will continue to focus on multimode-based optical interconnects while maintaining a keen eye on single-mode-based applications such as silicon photonics. The data center fiber optics solutions and services provider has made quick strides in the high integration of light source chips and optical fibers into silicon photonics chips. Recently, LESSENGERS demonstrated intra-chip and interchip multiple optical links in silicon photonics. Established in 2017, LESSENGERS continues to create an innovation in the optical interconnect space aggregating more than 35 granted and pending patents. The company will deliver more innovations in the coming years through its high-performance manufacturing-oriented DOW technology.
Share this Article:
LESSENGERS

Company
LESSENGERS

Headquarters
Pohang, South Korea

Management
Chongcook Kim, Founder, and CEO

Description
LESSENGERS has demonstrated an ultra-small optical module required for multi-mode waveguide interconnect system (MWIS) Working Group in the Consortium for On-Board Optics (COBO) with the advantage of high integration of DOW technology. The 56G signaling-based optical module comprises a 4-channel transmitter and 4-channel receiver, with an aggregate data rate of 224 Gbps and a small footprint of 10 × 30 mm2.

"Many of the challenges in the photonics space, specifically in the optical interconnects, originate from interfaces, where the conventional electronics and photonics meet to create highperformance optical signal transmissions"

- Chongcook Kim, Founder, and CEO