Hello, I'm going to be applying to grad schools this year (likely a Materials Science Program rather than Physics) and my interests are in semiconductors, opto-electronic materials, & photonics.
I'm what you might call a "non-traditional" applicant in that my undergrad was Mechanical Engineering, then I worked in a private R&D company as a thin-film semiconductor process engineer under 2 PhDs. One was the owner of the company, and the other was my direct supervisor. Now, about 3 years after, I am applying to graduate programs in that field.
One of my prospective LOR writers would be my professor in college who I did no research with, the other two would likely come from the 2 PhDs who I worked under in my first job.
They know me very well and I expect the LORs to be very good, but how much will it matter that they are in industry doing research instead of academia?