Method for stabilizing a diode laser

A method for stabilizing a diode laser with a semiconductor laser diode, a laser diode facet at an end of the semiconductor laser diode, and an external resonator, wherein the external resonator comprises at least one angle-dispersive, frequency-selective element,

• wherein the frequency of the diode laser is essentially determined by the length of the external resonator and by the position of the angle-dispersive, frequency-selective element,
• wherein these two frequency-selective elements or one element thereof can be detuned by way of a correction device,
• wherein a portion of the light reflected from the external resonator with the angle-dispersive, frequency-selective element back to the laser diode facet at the end of the semiconductor laser diode and not optically coupled by the laser diode facet into the semiconductor laser diode, or part thereof, is scattered by the laser diode facet in dependence on a focus position of the light reflected on the laser diode facet, falling past the semiconductor laser diode and directed by a collimation lens positioned on a front side of the semiconductor diode laser onto a detector arrangement without entering into the semiconductor laser diode, and is measured for controlling the diode laser, and
• wherein from the relevant measuring values, after comparison with a reference value, a fault signal is generated which as a control variable activates the correction device for synchronization of the frequency-selective elements.