放大镜是否可以聚焦红外线

当然可以了。因为红外线也是光，是光就会有光的属性。只是红外属于非可见光

YES.

If you are consider the kinds of macroscopic light,then it can, since i had satisfied all of the requirements of geometry optics.

But,when you are consider single photon, this do not work.Instead ,we must use quantum optics to seal with it.Anyway focusing do not work this time.

无法聚焦。因为周围物体辐射的红外线是散射光，而不是平行光，所以无法通过凸透镜聚焦。