Presentation of an external laser source for co-packaged optics at OFC2022

– Contribute to the realization of next-generation network switching servers in data centers –

March 7, 2022

For the first time in the world, Electric Furukawa will exhibit an external light source (ELS) for co-packaged optics (CPO) at OFC2022.

Sample shipment of QSFP Pigtail ELS will be initiated from April 2022.

Contribute to the realization of high-capacity data communication and a highly efficient energy society.

Furukawa Electric Co., Ltd. (Headquarters: 2-6-4 Otemachi, Chiyoda-ku, Tokyo; President: Keiichi Kobayashi) has developed for the first time in the world an ELS to be adopted for CPO required for next generation network switching servers in data centers (note 1) and will exhibit the ELS at OFC2022, the largest international conference on the optical communications market.


There has been a strong demand for bandwidth expansion for hyperscale data centers that process big data and edge data centers that achieve low latency for Beyond 5G. In line with this market trend, power saving has been a challenge for network switching servers. To date, the bandwidth of the ASIC (Application Specific Integrated Circuit) switch reaches 25.6 Tb/s. It is difficult for the existing server architecture using pluggable optical transceivers to support a higher bandwidth of 51.2 Tbps in the next generation. Therefore, it was planned to adopt CPO as a new server architecture.

The CPO has a unique packaging structure in which high-density silicon photonic transceivers are mounted with a switch ASIC on the same substrate. In order to expand the bandwidth of the switch ASIC, the power consumption is increased, resulting in higher heat. Therefore, if a light source, which is a compound semiconductor laser, is integrated with a silicon photonic optical transceiver, it will operate in a high temperature environment, which will deteriorate its characteristics and also affect its reliability. . An ELS can solve this problem because it is connected to a front panel where the ambient temperature is lower.


For the first time in the world, we will exhibit an ELS using the QSFP (Quad Small-Form Factor Pluggable) standard which has been widely used for pluggable optical transceivers in the optical communications market. The QSFP ELS supports hot-plug functionality that works automatically by inserting it into a cage located on a rack. The QSFP ELS has an 8 channel PMF (polarization maintaining fiber) cable to provide linearly polarized CW (continuous wave) laser outputs for a CPO transceiver and a standard MPO connector is attached to the end. fiber.

We have prepared two options for wavelength allocation: 1311 nm (O band) x 8 channels and 4-? CWDM (1271nm, 1291nm, 1311nm, 1331nm) x 2 channels. The operating box temperature range is as wide as 0 ºC to 55 ºC. The optical power coupled to the fiber is > 100 mW per channel.

QSFP ELS sample submission will be initiated from April 2022.

ELS utilizes high-power, wavelength-selected compound semiconductor laser technologies and optical conditioning technologies that Electric Furukawa built for 20 years.

Fig. 3 Photograph of a pigtailed QSFP ELS

Target specs

Specifying Parameters

Number of channels 8

Operating case temperature 0 ºC to 55 ºC

Wavelength allocation Option 1: 1311 nm (O band) x 8

Variation 2: 4-? CWDM x 2

Output power > 100 mW/channel

Polarization extinction ratio > 20 dB (slow axis)

(note 1) According to our research

Furukawa Electric Group efforts towards the SDGs

Based on “Sustainable Development Goals (SDGs)” adopted by the The United Nationsthe Furukawa Electric Group formulated the “Furukawa Electric Group Vision 2030” which sets the year 2030 as the goal and advances efforts to “Build a sustainable world and make people’s lives safe, peaceful and fulfilling, Furukawa Electric Group will create solutions for the next generation of global infrastructure combining information, energy and mobility. » Towards the achievement of our 2030 Vision, we will adopt open, agile and innovative approaches to promote ESG management which aims to increase the value of the company in the medium term. in the long term and will contribute to the achievement of the SDGs.


Shirlene J. Manley