ALMU
Aeluma, Inc. Common Stock
stock NASDAQ

Here's a couple that fit into the "advanced materials" sector but also fit into today's push into photonics.
ALMU - currently transitioning from R&D to commercialization, their quantum dot photo detectors utilize III-V semiconductor materials made of Indium and gallium arsenide grown on a Si substrate.
LWLG - These people have a proprietary polymer that achieves extremely high electro-optic (EO) coefficients that can "modulate" light (sort of like modulating RF) at very high speeds with very low energy consumption. Not quite as far along commercialization-wise as ALMU but certainly worth checking out.

DAMN, missed ALMU morning dip opportunity

ALMU dip opportunity