A method of frequency and mode stabilizing a tuneable laser, wherein one or more
measurable magnitudes is/are measured, wherein the laser has been characterized
with respect to a number of operation points, and wherein the values of the measurable
magnitude or magnitudes are stored in a microprocessor or corresponding device.
The invention is characterized by causing the values of one or more of the measurable
magnitudes to be non-extreme values; storing the values of such non-extreme values
as a quotient where the numerator is the derivative of a measurable magnitude Y
with respect to a control current I to one laser section, and where the
denominator is the derivative of another measurable magnitude Z with respect
to said control current I; and using the stored values to control the laser
to a desired operation point.
