Optical device having partially butt-coupled light sensor
View Patent ↗An optical device includes a light-transmitting medium positioned on a base. The light-transmitting medium defines a waveguide. The optical device also includes a light sensor. The light sensor includes a light-absorbing medium positioned on the base. A portion of the waveguide ends at a facet such that a first portion of a light signal being guided by the wavegide passes through the facet and a second portion of the light signal bypasses the facet and remains in the light-transmitting medium. The light-absorbing medium is positioned on the light-transmitting medium such that the light-transmitting medium is between the light-absorbing medium and the base. Additionally, the light-absorbing medium is positioned on the light-transmitting medium such that the light-absorbing medium receives the first portion of the light signal that passes through the facet. Further, the light-absorbing medium is configured such that the second portion of the light signal is coupled into the light-absorbing medium from the light-transmitting medium.
1. An optical device, comprising:
a light-transmitting medium positioned on a base;
a light sensor positioned on the base, the light sensor including a continuous light-absorbing medium positioned on the base,
the light-transmitting medium defining a waveguide,
a portion of the waveguide ending at a facet such that a first portion of a light signal guided by the waveguide is received by the light-absorbing medium after exiting from the waveguide through the facet, and
a second portion of the light signal bypasses the facet when traveling from the waveguide into an underlying portion of the light-transmitting medium, the underlying portion of the light-transmitting medium being between the light-absorbing medium and the base, and
the light-absorbing medium configured such that the second portion of the light signal is coupled into the light-absorbing medium from the underlying portion of the light-transmitting medium.
2. The device of claim 1 , wherein the light-absorbing medium includes a second facet that contacts the facet of the waveguide.
3. The device of claim 1 , wherein a first doped region is positioned in a portion of the light-transmitting medium that is located between the light-absorbing medium and the base.
4. The device of claim 3 , wherein the first doped region contacts the light-absorbing medium.
5. The device of claim 4 , wherein the light-absorbing medium includes a second doped region.
6. The device of claim 5 , wherein the second doped region is arranged such that a portion of the light-absorbing medium is located between the second doped region and the first doped region.
7. The device of claim 6 , wherein the portion of the light-absorbing medium is between the second doped region and the light-transmitting medium.
8. The device of claim 7 , wherein the second doped region contacts the top of the light-absorbing medium.
9. The device of claim 1 , wherein the light absorbing medium includes a first doped region and a second region and the first doped region is located between the second region of the light absorbing medium and the base.
10. The device of claim 9 , wherein the first doped region contacts the light-transmitting medium.
11. The device of claim 10 , wherein the light-absorbing medium includes a second doped region and the second region of the light absorbing medium is between the first doped region and the second doped region.
12. The device of claim 11 , wherein the second doped region contacts the top of the light-absorbing medium.
13. The device of claim 1 , further comprising:
electronics configured to apply electrical energy to the light-absorbing medium in a reverse bias so as to form an electrical field in the light-absorbing medium.
14. The device of claim 1 , wherein the waveguide is not located between the light-absorbing medium and the base.
15. The device of claim 1 , wherein the second portion of the light signal bypasses the facet without traveling through the facet.
16. The device of claim 1 , wherein the portion of the light-transmitting medium that define the waveguide is continuous with the light-transmitting medium.
17. The device of claim 1 , wherein the facet of the waveguide is a facet of the light-transmitting medium and the second portion of the light signal travels between the facet of the light-transmitting medium and the base when bypassing the facet of the light-transmitting medium.