Let's about the optics that go into your router.  We're going to talk about ZR and ZR+ and open XR and stuff like that. 
So this is what you need to know about optics coming through the router: longer reach, leaner infrastructure, and lockout or the non lock in nonproprietary open system that allows to choose different vendors for your infrastructure.  
Watch CloudNets https://drivenets.com/resources/cloud-nets/season-2-ep-1-optics/