Display devices with bridge emitters and sensors

An electronic device comprising:

• a projector configured to generate first light;
• a first waveguide having a first optical coupler configured to couple the first light into the first waveguide, having a second optical coupler configured to couple the first light out of the first waveguide, having a partial reflector overlapping the projector and the first optical coupler, and having a third optical coupler;
• a second waveguide having a fourth optical coupler;
• a light source configured to emit second light into the second waveguide, wherein
• the fourth optical coupler is configured to couple the second light out of the second waveguide and towards the first waveguide,
• the third optical coupler is configured to couple a portion of the second light into the waveguide,
• the partial reflector is configured redirect the portion of the second light back towards the third optical coupler as reflected light,
• the third optical coupler is configured to couple the reflected light out of the first waveguide and towards the second waveguide, and
• the fourth optical coupler is configured to couple the reflected light into the second waveguide;
• and
• an optical sensor configured to receive the reflected light through the second waveguide and configured to generate optical sensor data based on the reflected light.

An electronic device comprising:

• a first waveguide configured to propagate first light;
• a first optical coupler on the first waveguide and configured to couple the first light out of the first waveguide;
• a second waveguide;
• one or more vertical-cavity surface-emitting lasers (VCSELs) configured to emit second light;
• a second optical coupler on the second waveguide and configured to couple the second light into the second waveguide;
• a third optical coupler on the second waveguide and configured to couple the second light out of the waveguide and towards the first waveguide;
• a fourth optical coupler on the first waveguide and overlapping the second waveguide, wherein the fourth optical coupler is configured to reflect at least some of the second light back towards the third optical coupler as reflected light, the third optical coupler is configured to couple the reflected light into the second waveguide, and the second optical coupler is configured to couple the reflected light out of the waveguide;
• and
• an array of photodiodes configured to generate electrical signals based on the reflected light coupled out of the waveguide by the fourth optical coupler.