Segmented distributed feedback laser

A method of fabricating a semiconductor laser, comprising:

• forming a plurality of semiconductor layers on a substrate, a first one of the first plurality of semiconductor layers being a first cladding layer and a second one of the first plurality of semiconductor layer being a grating layer provided on the first cladding layer;
• forming first and second pluralities of segmented gratings in the grating layer, each of the first and second pluralities of segmented gratings including a non-grating portion and a grating portion, the first plurality of segmented gratings spaced from the second plurality of segmented gratings along a longitudinal axis of the grating layer to define a cavity, a length of the cavity being different than a length of each non-grating portion of each of the first and second pluralities of segmented gratings;
• forming first and second gratings in the grating layer, such that the first and second pluralities of segmented gratings are provided between the first and second gratings, the first grating extending to a first edge of the grating layer and the second grating extending to a second edge of the grating layer;
• forming a second cladding layer on the grating layer;
• forming an active layer on the second grating layer;
• forming a third cladding layer on the active layer;
• forming a contact layer on the third cladding layer;
• and
• forming a conductive layer on the contact layer.