A laser in which two beams are made to travel in opposite directions around a closed path by means of mirrors, typically used in aircraft, missiles, etc., in order to detect rotation; frequently attributive, as "ring laser gyroscope", etc.; (also) any of various other lasers in which the light is made to travel around a ring.
Origin
1960s.
Definition of ring laser in US English:
ring laser
noun
Physics
A laser in which two beams are made to travel in opposite directions around a closed path by means of mirrors, typically used in aircraft, missiles, etc., in order to detect rotation; frequently attributive, as "ring laser gyroscope", etc.; (also) any of various other lasers in which the light is made to travel around a ring.