This may help :

“Over the past two years, we have established redundancy for critical activities in Singapore, Shenzhen and Allentown, Pennsylvania, both to accelerate development and to cope with COVID-19 lockdowns,” reported Dr. Suresh Venkatesan, CEO of POET Technologies. “On Sunday, March 13, 2022, our operation in Shenzhen, China was notified that it would be shut down until at least March 20, 2022, due to a COVID-19 outbreak in that city. We promptly tasked both Singapore and our joint venture, Super Photonics Xiamen, with the task of continuing to build samples for customers. Because we have been well-prepared for such a contingency, we do not believe this temporary lockdown will have any effect on our planned delivery schedule to customers, prospective customers or business partners.”

https://www.globenewswire.com/news-release/2022/03/15/2403821/0/en/POET-Technologies-Responds-to-Shenzhen-Lockdown.html