The 7 Layers of Photonics 1. Materials & Wafers: $AXT Inc(AXTI)$ $Aeluma, Inc.(ALMU)$ $Teck Resources Ltd(TECK)$ $IQE(IQE.UK)$ $Lightwave Logic, Inc.(LWLG)$ $SCHRODER ORIENT(SOI.UK)$ $Wolfspeed Inc.(WOLF)$ 2. Tools: $Aixia Group AB(AIXAF)$ $Veeco Instruments(VECO)$ $Lam Research(LRCX)$ $Applied Materials(AMAT)$