The application discloses a preparation method and structure of an electro-absorption modulated
laser, and the method comprises the following steps: a substrate is symmetrically divided into a double-end modulation area, a
gain area, a
grating area and a phase area; a first
mask pattern is made on the surface of the
gain area; a selective
epitaxy technology is used to grow an
active layer containing a
quantum well structure in the
mask gap, so that the
band gap of the
gain area is red-shifted; then, a
mask covering the gain area and the modulation area is made, and a non-functional area is etched to
expose the substrate; a passive material with a wider
band gap is grown on the exposed substrate area, so as to form a
photon confinement structure; a sampling
grating is made by
electron beam
direct writing, a cladding layer and a
contact layer are grown, and an inverted mesa shallow
ridge waveguide is etched; finally, an electrically isolated groove is etched, and double-sided electrodes are made to complete device integration. By using the selective
epitaxy growth technology, the active materials with two kinds of
band gap widths of the gain area and the modulation area are realized by one-time
epitaxy growth, so that an extremely low-cost solution is provided for a
wavelength tunable electro-absorption modulated
laser.