Integrated grating coupler system

An integrated grating coupler system comprising:

• a first chip having a first substrate, a first grating structure formed by first grating curves arranged on the first substrate and a cladding layer formed to cover the first grating structure, wherein the first chip include a first waveguide configured to receive a light beam from a first end via the first waveguide and transmit the light beam through a second end;
• and
• a second chip having a second substrate and a second grating structure formed by second grating curves arranged on the second substrate, wherein the second chip is configured to receive the light beam from the second end of the first chip and transmit the light beam from an end of the second chip, wherein a part of the second chip includes a concave area such that the first chip is disposed on the concave area of the second chip, wherein a depth of the concave area is formed to achieve a height difference between a top of the first chip and a top of the second chip such that the light beam from the second end of the first chip is received at a top of the second chip.