Integrated high-speed high-channel-count optical transceivers

An optical link, comprising:

• an optical transceiver comprising:
• an optical-emitter chip having multiple light sources configured to emit first optical signals in parallel, wherein the multiple light sources are arranged in a two-dimensional array;
• an optical-receiver chip having multiple photodetectors configured to detect second optical signals in parallel, wherein the multiple photodetectors are arranged in a two-dimensional array;
• and
• a circuitry chip having circuitry configured to control the optical-emitter chip and the optical-receiver chip,
• wherein the optical-receiver chip is stacked between the optical-emitter chip and the circuitry chip, and
• wherein each of the multiple photodetectors comprises:
• a silicon layer having a first surface and a second surface, the silicon layer comprising:
• a trench formed along the first surface;
• an n-doped region;
• a p-doped region formed along the second surface;
• and
• a first absorption region formed between the n-doped region and the p-doped region;
• and
• a second absorption region formed in the trench, wherein the second absorption region comprises germanium, and
• wherein the n-doped region and the p-doped region are biased to form an amplification region in the first absorption region.

An optical link, comprising:

• an optical transceiver comprising:
• an optical-emitter chip having multiple light sources configured to emit first optical signals in parallel, wherein the multiple light sources are arranged in a two-dimensional array;
• an optical-receiver chip having multiple photodetectors configured to detect second optical signals in parallel, wherein the multiple photodetectors are arranged in a two-dimensional array;
• and
• a circuitry chip having circuitry configured to control the optical-emitter chip and the optical-receiver chip,
• wherein the optical-receiver chip is stacked between the optical-emitter chip and the circuitry chip, and
• wherein each of the multiple photodetectors comprises:
• a high-conductivity region that is p-doped;
• a high-field region that is n-doped;
• and
• an absorption region arranged between the high-conductivity region and the high-field region,
• wherein the absorption region is configured to receive an optical signal of the second optical signals and to generate electrons and holes,
• wherein the high-conductivity region is configured to collect at least a portion of the holes,
• wherein the high-field region is configured to collect at least a portion of the electrons,
• wherein a peak doping concentration of the absorption region is lower than a peak doping concentration of the high-conductivity region, and
• wherein a thickness of the high-field region is smaller than an absorption length associated with a wavelength of the optical signal.