A new concept, defined as spectral-gate injection seeding, is proposed
for coupling the master oscillator (MO) and the forced oscillator (FO
) in tunable injection-seeding laser systems. It is based on the use o
f a spectral selector as a tunable narrowband spectral gate between th
e partially coupled MO and FO cavities. The concept proposed enables o
ne to implement compact and efficient injection-seeded tunable lasers.
It is demonstrated experimentally on Nd:YAG-laser pumped dye lasers w
ith a Fizeau interferometer as a spectral gate. Full suppression of th
e FO's broadband spectral background is achieved even when the MO oper
ates near the threshold. (C) 1996 American Institute of Physics.