Method for making a Distributed Bragg Reflector, DBR, laser diode device with a distributed grating reflector (RT) in a planar section of a semiconductor laser with stabilized wavelength, comprising the steps of: - providing a diode formed by a substrate (S), at least one first cladding layer (CL1) arranged on the substrate (S), an active layer (A) arranged on the first cladding layer (CL1) and adapted to emit a radiation, and at least one second cladding layer (CL2) arranged on the active layer (A), said cladding layers (CL1, CL2) being adapted to form a heterojunction to allow for efficient injection of current into the active layer (A) and optical confinement, and a contact layer (C), - creating, on a first active portion (ZA) of the device, a waveguide (GO) configured to provide confinement of the optical radiation, - -creating, on the remaining passive portion (ZP) of the device, two different gratings for light reflection and confinement, wherein said two gratings are laterally adjacent to each other along an optical axis of said DBR laser diode and define two different zones (R1, R2), wherein the first zone (R1) comprises a grating of low order and is configured for reflection, wherein the second zone (R2) is laterally adjacent to the first zone (R1) on both sides of the first zone (R1) along the optical axis and comprises a grating of the same order, or a grating of a higher order than the previous one, wherein the duty cycle of the grating of the first zone (R1) is higher than the duty cycle of the grating of the second zone (R2), and wherein the reduced volume of the semiconductor material in the second zone (R2) is configured for lateral optical confinement by the lower effective refractive index of the second zone (R2) in comparison to the effective refractive index of the first zone (R1). - providing a diode formed by a substrate (S), at least one first cladding layer (CL1) arranged on the substrate (S), an active layer (A) arranged on the first cladding layer (CL1) and adapted to emit a radiation, and at least one second cladding layer (CL2) arranged on the active layer (A), said cladding layers (CL1, CL2) being adapted to form a heterojunction to allow for efficient injection of current into the active layer (A) and optical confinement, and a contact layer (C), - creating, on a first active portion (ZA) of the device, a waveguide (GO) configured to provide confinement of the optical radiation, - -creating, on the remaining passive portion (ZP) of the device, two different gratings for light reflection and confinement, wherein said two gratings are laterally adjacent to each other along an optical axis of said DBR laser diode and define two different zones (R1, R2), wherein the first zone (R1) comprises a grating of low order and is configured for reflection, wherein the second zone (R2) is laterally adjacent to the first zone (R1) on both sides of the first zone (R1) along the optical axis and comprises a grating of the same order, or a grating of a higher order than the previous one, wherein the duty cycle of the grating of the first zone (R1) is higher than the duty cycle of the grating of the second zone (R2), and wherein the reduced volume of the semiconductor material in the second zone (R2) is configured for lateral optical confinement by the lower effective refractive index of the second zone (R2) in comparison to the effective refractive index of the first zone (R1). <EOS>