HR reach out first Hiring Manager Interview with 1 hr. No question related to your resume or experience but all about the job descrition even though they know you lack of some of the experience. It seems they want someone can directly fit in,

First is phone screen. Passed; Then, video interview with HR, asked detail questions. It is a fair interview process. Ask questions based on Job description. I don't know much about optical simulation with FRED software, which they care most.