The hypothesis of the moving comb in frequency shifted feedback lasers

H. Guillet de Chatellus (1) , E. Lacot (1) , W. Glastre (1) , O. Jacquin (1) , O. Hugon (1)

1 OPTIMA-LIPhy - OPTique et IMAgeries [Grenoble]

The use of frequency-shifted feedback (FSF) lasers in optical metrology is based on a unique coherence property: the appearance of beats in the noise spectrum at the output of a two-beam interferometer, whose frequencies vary linearly with the path delay of the interferometer. A description of the output of a FSF laser as a moving comb of optical frequencies is generally admitted to explain these specific coherence properties. Here starting from the model of a passive FSF cavity seeded by spontaneous emission we give a rigorous description of the time-spectrum properties of FSF lasers and show that the moving comb exists only in the limit of small frequency shift.

Mots clés: Frequency shifted feedback laser; Laser coherence; Time-frequency spectrum; Gauss sums; Talbot effect

Domaines: Optique [physics.optics]

H. Guillet de Chatellus, E. Lacot, W. Glastre, O. Jacquin, O. Hugon. The hypothesis of the moving comb in frequency shifted feedback lasers. Optics Communications, 2011, 284, pp.4965-4970. ⟨10.1016/J.OPTCOM.2011.06.042⟩. ⟨hal-00951867⟩