Two-segment DBR laser and monolithically integrated array light source chip

A monolithically integrated array light source chip, comprising N integrated monolithics, wherein each of the N integrated monolithics comprises a second bottom liner and a four-channel laser array integrated on the second bottom liner, and N is an integer greater than or equal to 1, wherein:

• the four-channel laser array comprises four two-segment DBR lasers, each of which is configured to generate a light wave of a wavelength, and wherein each two-segment DBR laser comprises:
• a grating region for selecting the light wave of the wavelength, a gain region, and a broadband reflector for reflecting light waves, wherein:
• the grating region and the broadband reflector are respectively disposed at two ends of the gain region;
• the grating region comprises a first bottom liner, a first support structure, a first ridge waveguide structure, and a first heater;
• the first ridge waveguide structure comprises a first ridge portion, a first trench portion, a second trench portion, a first protection structure, and a second protection structure, and wherein a height of the first ridge portion over the first bottom liner is the same as a height of the first protection structure over the first bottom liner, the height of the first ridge portion over the first bottom liner is a distance from a surface of the first ridge portion that is closest to the first bottom liner to a surface of the first ridge portion that is farthest from the first bottom liner, and the height of the first protection structure is a distance from a surface of the first protection structure that is closest to the first bottom liner to a surface of the first protection structure that is farthest from the first bottom liner;
• the first ridge waveguide structure is fastened by the first support structure and suspended in midair above the first bottom liner, and the first bottom liner, the first support structure and the first ridge waveguide structure jointly form a cavity;
• in a plan view of the first ridge waveguide structure, the first support structure does not extend beyond a periphery of the first protection structure and the second protection structure;
• a distance between two opposite side walls of the first support structure is greater than a distance between two opposite side walls of the first protection structure and the second protection structure;
• a reflectivity of the broadband reflector is greater than 80 percent, and a coverage range with respect to a center wavelength of the broadband reflector is greater than 50 nanometers (nm);
• and
• the first heater is located on a surface that is of the first ridge waveguide structure and that faces away from the cavity;
• and
• each of the first protection structure, the second protection structure, and the first ridge portion have a same number of layers, and each of the first protection structure, the second protection structure, and the first ridge portion have more than one layer.

A two-segment distributed bragg reflector (DBR) laser, comprising:

• a grating region for outputting a light wave of a selected wavelength;
• a gain region;
• and
• a broadband reflector for reflecting light waves of wavelengths, the broadband reflector comprising a film deposited on a surface, wherein a reflectivity of the broadband reflector is greater than 80 percent, and a coverage range of with respect to center wavelength of the broadband reflector is greater than 50 nanometers (nm);
• and
• wherein:
• the grating region and the broadband reflector are respectively disposed at two ends of the gain region;
• the grating region comprises a first bottom liner, a first support structure, a first ridge waveguide structure, and a first heater;
• the first ridge waveguide structure comprises a first ridge portion, a first trench portion, a second trench portion, a first protection structure, and a second protection structure, and wherein a height of the first ridge portion over the first bottom liner is the same as a height of the first protection structure over the first bottom liner, the height of the first ridge portion over the first bottom liner is a distance from a surface of the first ridge portion that is closest to the first bottom liner to a surface of the first ridge portion that is farthest from the first bottom liner, the height of the first protection structure is a distance from a surface of the first protection structure that is closest to the first bottom liner to a surface of the first protection structure that is farthest from the first bottom liner;
• the first ridge waveguide structure is fastened by the first support structure and suspended in midair above the first bottom liner, and the first bottom liner, the first support structure and the first ridge waveguide structure jointly form a cavity;
• in a plan view of the first ridge waveguide structure, the first support structure does not extend beyond a periphery of the first protection structure and the second protection structure;
• a distance between two opposite side walls of the first support structure is greater than a distance between two opposite side walls of the first protection structure and the second protection structure;
• the first heater is located on a surface that is of the first ridge portion and that faces away from the cavity;
• and
• the surface of the broadband reflector on which the film is deposited comprises a first surface and a second surface, and the second surface is recessed compared to the first surface.