This technology enables frequency counters for laser light.[1] Input a red laser, and you can directly measure its frequency in Hertz with 14 digits of precision.
[1] https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=11...
[1] https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=11...
Under "Measurement Wavelength" it says "Choose one in the 630-2000 nm range," and often that type of specification means you have to specify the nominal frequency up front when you order it. Either way, it seems to be a big step forward in commercializing this stuff. The comb hardware I've seen takes up a good chunk of an entire room.