News: Optoelectronics
3 December 2020
POET releases multi-product mask set to production
POET Technologies Inc of Toronto, Ontario, Canada — designer and developer of the POET Optical Interposer and photonic integrated circuits (PICs) for the data-center and telecom markets — has launched its first multi-product wafer (MPW) mask set for production. The MPW comprises multiple products, including custom designs for specific applications and customers.
The MPW tape-out, which commits product designs to manufacturing, incorporates all the new features of the Optical Interposer announced in late October and is largely in-line with the product roadmap presented at the firm’s Annual General Meeting in August. Included are designs for two variants of 100G CWDM4 optical engines for two different customers, a 100G design for an LR4 transmit optical sub-assembly (TOSA), a 400G receive optical sub-assembly (ROSA) and a 400G FR4 externally modulated laser (EML)-based optical engine, and three different designs for light engines, including two operating in the O-band for datacoms applications and another in the C-band for sensing and computing applications. The tape-out also includes various test structures for evaluation and incorporation in future product designs.
New features announced previously and now incorporated into the Optical Interposer enhance critical performance, manufacturability and versatility of the platform.
To improve the overall performance of the Optical Interposer in transmitting light without significant losses, POET produced waveguide designs that minimized or eliminated reflections of light at the interface of the laser and the waveguide, a problem that is common in photonic device integration. In addition, the firm incorporated several features that minimize losses as light travels through the device, including its latest generation of Mach-Zehnder interferometry (MZI)-based multiplexers, which reduce the loss of signal from this device to less than 20% (<1.0dB), which is believed to be industry-leading performance for this type of device. Improved spot-size converters, able to match different diameters (modes) of light beams (for more efficient coupling between devices), were implemented with losses of less than 10% (<0.5dB), far exceeding best-in-class, it is claimed. To connect efficiently to off-the-shelf components, such as top-entry photodetectors and vertical-cavity surface-emitting lasers (VCSELs), POET incorporated improved vertical mirrors into the Optical Interposer, expanding the overall versatility of the platform. The firm designed unique fiber-attach-units (FAUs) with matching passive alignment structures on the Optical Interposer that facilitates alignment while providing a low-loss attachment of POET’s optical engines in customers’ transceivers. Finally, new designs of fiducials on both the Optical Interposer and POET-designed lasers better enable sub-micron accuracy for mechanical pick-and-place assembly of components.
“The tape-out that we sent to our silicon fabrication foundry today represents the culmination of many months of design and development work by our team of highly experienced and dedicated engineers and consultants,” says chairman & CEO Dr Suresh Venkatesan. “We have made tremendous progress in the past few months, refining designs, calibrating our simulation models and preparing for the fabrication of prototype designs of optical engines and sub-assemblies,” he adds. “Once fabricated, the Optical Interposer wafers will be sent to POET Singapore or Super Photonics Xiamen (our joint venture with Sanan IC) for component assembly, test and packaging of alpha prototypes. We intend to use these prototypes to sample prospective customers and to collect additional data that will conclusively demonstrate to customers the superior performance of POET’s optical engines. We look forward to announcing specific products over the course of the next several weeks as we continue on our path to the commercialization of POET’s Optical Interposer platform.”
POET readies Optical Interposer for production
POET and Sanan IC to form Super Photonics Xiamen
