Avstämbar laser jämte förfarande att avstämm densamma

摘要

A tuneable laser that includes a gain section (11; 34) and a tuneable wavelength-selective filter (12; 27). The invention is characterised in that a reflection filter in the form of an external reflector (13) is adapted to give a number of fixed reflection maxima, where each maximum corresponds to a given wavelength. The reflection filter is adapted to coact with the tuneable filter and the laser is adapted to be tuned to lase at any selected one of said wavelengths, by tuning the tuneable filter (12; 27). The invention also relates to a method.