Assertion: erbium | /r/ObjectUse | used as photographic filter
Facets:
value: as a fiber-optic amplifier
type: PURPOSE
Source sentences:
text: It is used as a photographic filter and also as a neutron absorber in nuclear technology.
text: Erbium is used in heat-absorbing glass, photographic filters, and as a fiber-optic amplifier.
text: Erbium is used as photographic filter.