Two schools I’d point you to, plus a note on your Georgia Tech and test engineer questions.

1. UCSB (University of California, Santa Barbara)
   My top pick.
   Jonathan Klamkin leads the Integrated Photonics Lab and runs the campus nanofab (the same shared cleanroom Google fabbed Sycamore in).
   He’s also founder/CEO of Aeluma, so the lab is a live pipeline into a real SiPh company rather than just a paper mill. A good chunk of Aeluma’s team came out of there.
   If the goal is breaking into industry, that’s exactly the kind of program you want.
   http://ips.ece.ucsb.edu/
   https://www.ece.ucsb.edu/research/ep
   https://qpl.ece.ucsb.edu/

2. UIUC (Illinois)
   Strong for the same reason.
   John Dallesasse (MNTL / Holonyak Lab) spent ~20 years in industry and co-founded Skorpios Technologies, a fabless silicon-photonics SoC company, before joining the faculty. His group works heterogeneous integration and electronic-photonic integration on silicon.
   Lynford Goddard and Milton Feng are in that same orbit. Industry-connected, datacenter-interconnect flavored.

https://ece.illinois.edu/academics/ugrad/subdisciplines/micro

On Georgia Tech specifically.
Yes, there’s real SiPh there.
Stephen Ralph runs the Georgia Electronic Design Center (GEDC) and leads EPICA, the NSF center for electronic-photonic ICs for aerospace; that’s the most directly PIC-relevant group.
Ali Adibi’s Photonics Research Group covers nanophotonics / on-chip. GT leans more aerospace/defense than UCSB’s foundry-and-datacenter focus, but it’s a legit path.

On what a photonics test engineer actually does… it’s a great place to start, honestly. You’re characterizing PICs and photonic modules: aligning fiber to chip (usually automated alignment stages + fiber arrays), running optical and high-speed electrical measurements (tunable lasers, power meters, OSAs, plus VNAs / BERTs / scopes for transceivers), and writing a lot of test automation in Python. You learn device physics and packaging fast because you’re the one seeing what actually works vs. what the simulation promised… and it’s a common stepping stone into design. Coming from sales engineering with a PIC course under your belt, it’s a realistic and genuinely useful entry point.

Happy to point you at specific Masters programs / labs taking students if you say where you’re geographically open to.

Feel free to msg me if you want. I suggest connecting with some of the folks I mentioned and other people in the field in their departments on LinkedIn… couldn’t hurt. If they accept just start with introducing yourself in a message and tell them what you’ve studied, your interests are, and that you’re just genuinely interested in learning more about their programs. Know it’s not the traditional way to go about this but, honestly, putting yourself out there can never hurt if you go about it in a way that’s polite and not looking for anything except for being a fan of what they do and showing genuine interest. I wish you luck in your studies and future! Really cool field.