Continuously wavelength-tunable monomode laser source

An external cavity, continuously wavelength-tunable monomode laser source comprising a resonant cavity, resonating at an emission wavelength λe, with:

• a spatially monomode, amplifying wave guide, located inside the resonant cavity, said wave guide having an intracavity face treated with an antireflection coat,
• collimation optics with a focus, the intracavity face of the wave guide being located at the focus of said optics,
• a partially reflecting output face on said wave guide,
• extraction means for extracting a portion of intracavity flux from said wave guide,
• a retroreflecting wavelength dispersing device, arranged with respect to the wave guide and to the collimation optics to produce a wavelength selectivity curve with a peak power wavelength λs,
• primary mechanical means for interrelating said wave guide and said retroreflecting wavelength dispersing device for substantially continuous tunability of said laser source, and
• additional fine-control means, for enabling from an approximate continuous tunability position, monitoring and controlling a deviation λe−λs so that during the variation of the emission wavelength λe, the deviation is prevented from reaching at least one of plural limits which would cause mode hopping of said laser source.