An extended-cavity diode laser operating in the Littrow configuration emitting near 657 nm is stabilized through its injection current to a reference cavity with a finesse of more than 10<sup>5</sup> and a corresponding resonance linewidth of 14 kHz. The laser linewidth is reduced from a few megahertz to a value below 30 Hz. The compact and robust setup appears ideal as a portable optical frequency standard that uses the calcium intercombination line.
© 2001 Optical Society of America
(020.0020) Atomic and molecular physics : Atomic and molecular physics
(120.3940) Instrumentation, measurement, and metrology : Metrology
(300.6260) Spectroscopy : Spectroscopy, diode lasers
(300.6360) Spectroscopy : Spectroscopy, laser
A. Schoof, J. Grünert, S. Ritter, and A. Hemmerich, "Reducing the linewidth of a diode laser below 30 Hz by stabilization to a reference cavity with a finesse above 105," Opt. Lett. 26, 1562-1564 (2001)