Source of beam installed in Agricola's era (5)
I believe the answer is:
laser
'source of beam' is the definition.
'laser' can be an answer for 'beam' (laser beam is a kind of beam). I am not sure about the 'source of' bit.
'installed in agricola's era' is the wordplay.
'installed in' says the answer is hidden in the clue.
'LASER' is hidden in the letters of 'agricolas era'.
Can you help me to learn more?
(Other definitions for laser that I've seen before include "type of surgery" , "Source of intense beam" , "scientific device" , "Coherent light-beam" , "Device producing thin beam of light" .)