Assertion: laser's beam | /r/HasProperty | generated by single pass
Facets:
value: through the gain medium
type: MANNER
Source sentences:
text: Because of high gain in the lasing medium, short upper-state lifetimes (1–100 ps), and problems associated with construction of mirrors that could reflect X-rays, X-ray lasers usually operate without mirrors; the beam of X-rays is generated by a single pass through the gain medium.