Quantum coherence and interference effects in atomic and
molecular physics have been extensively studied because of
intriguing counterintuitive physics and potential important applications.
Here we present one such application, i.e. using
quantum coherence to generate and enhance gain in the extreme
ultra-violet (XUV)(@58.4nm in Helium) and infra-red
(@794.76nm in Rubidium) regimes of electromagnetic radiation.
We show that using moderate external coherent drive,
a substantial enhancement in the output energy on the lasing
transition can be achieved under optimal conditions. We also
discuss the role of coherence. The present paper is intended
to be pedagogical on this subject of coherence-enhanced