Method for integration of variable Bragg grating coupling coefficients

A method of manufacturing a photonic integrated circuit, comprising:

• forming a first laser including a first grating that is a first mirror along a first waveguide, wherein
• the first grating has first grooves formed substantially perpendicular to a direction that light travels in the first waveguide,
• the first grooves have a depth,
• the first grooves have a first non-etched gap with a first varying width chosen to achieve a specified first K of the first mirror, where K is the coupling coefficient of the grating wherein the value of the first k changes as the width of the first non-etched gap varies thereby achieving different first k changes and being formed in a single lithography and etch step by introducing the first non-etched gap in a central region along the length of the first grating;
• and
• forming a second laser including a second grating that is a second mirror and a third grating forming a third mirror along a second waveguide, wherein
• the second grating has second grooves formed substantially perpendicular to a direction that light travels in the second waveguide,
• the second grooves have a depth that is the same is the depth of the first grooves,
• the second grooves have a second non-etched gap with a second width chosen to achieve a specified second K of the second mirror with multiple reflectivity peaks formed, spaced apart in wavelength at a period inversely proportional to a period of a sampling of the second and third gratings whereby the second and third mirrors are sampled at different periods such that only one multiple reflection peak can coincide at a time;
• wherein the first laser and the second laser are different types of lasers, and wherein the first grating and the second grating are formed during the same lithographic and etching step.