Frequency-modulation spectroscopy with a multimode dye laser.
A multimode laser in frequency-modulation spectroscopy gives a signal that is broader than the absorption line by an amount that is determined by how sharp the edges of the laser profile are, not by the total bandwidth of the laser. We have experimentally demonstrated that one can therefore obtain frequency-modulation signals that are narrower than the total bandwidth of the laser.
Pattnaik
R K
RK
Supplee
J M
JM
Whittaker
E A
EA