Traditional optics can achieve the economic benefits common to silicon photonics with its use of equipment, processes and fabrication plants paid for by the chip industry. So argues Valery Tolstikhin, head of design consultancy Intengent and former founder and CTO of Canadian start-up OneChip Photonics.
Tolstikhin says the rise of silicon photonics has sparked a general interest in the economics of component making. At present, indium phosphide fabs use specialist processes to make relatively low volumes of optical components.
Tolstikhin wants traditional optical component designs to piggyback on higher-volume indium phosphide and gallium arsenide fabs that make electronic devices such as monolithic microwave integrated circuits (MMICs) for wireless.
“To take photonics out of boutique fabs, you need to do some standardisation and move to a fabless model, then you can load the fabs day and night with wafers,” said Tolstikhin. “That is the only way to make a process mature, reproducible and reliable.”
To use such MMIC fabs requires that optical devices are designed to be process compatible, requiring them to be manufacturable without using wafer regrowth stages. This is something that Intengent can do and what OneChip Photonics demonstrated with its optical designs.
Intengent acts as a bridge between OEMs building optical components and sub-systems, and III-V foundries that make photonic chips for them. “The aim is that you can go and design within existing fabs and processes something that meets the customer’s application and requirements,” he said.
One company Intengent is working with is ELPHiC, a Canadian start-up that is raising funding to make single-mode mid-board optics. The indium-phosphide design combines analogue electronic circuitry with the photonics.