Distributed feedback lasers and methods for fabricating such lasers

A method for fabricating a DFB laser, comprising:

• providing a planar substrate, an active layer substantially parallel to the planar substrate but not coplanar with said planar substrate, and a grating layer arranged in a planar layer substantially parallel to said active layer but not coplanar with said active layer and arranged on a side of the active layer opposite to the planar substrate;
• covering with a mask a first section of an ensemble made of said planar substrate, said active layer and said grating layer, wherein said first section is intended to produce a laser section;
• removing at least the grating layer in a second section of said ensemble made of said planar substrate, said active layer and said grating layer, wherein said second section is intended to produce a mirror section;
• providing, in a single step, a grating mask covering at least partially the first section and at least partially the second section;
• such grating mask being configured to define a first Bragg grating in the first section and a second Bragg grating in the second section;
• and
• producing, using said grating mask, the first Bragg grating in the grating layer of the first section and the second Bragg grating in a planar layer of the second section that is coplanar with the active layer.