I have been covering test and measurement companies as someone who came from that industry. These companies are winning today, and they will continue winning as the AI buildout accelerates.

VIAVI, Keysight, Anritsu (6754.T), FormFactor, Teradyne, Santec (6777), Aehr, and others will keep seeing orders flow in for their test equipment.

What most people here do not realize is that some of these companies also supply critical components to each other. Santec for example provides tunable lasers to at least one peer (without naming them) as part of an OEM agreement: the buyer packages their laser and resells them as its own standalone product.

You need all of these equipment manufacturers (and then some) to test your PICs and optical transceivers from subassembly through R&D all the way to final module. As for production, some other names might appear to lower the cost of production, but these companies will remain the reference moving forward.

Long all of these names. NFA. DYOR.