Integrated optoelectronic device including a semiconductor optical amplifier and a photodiode
The field of the invention is that of optoelectronic devices for receiving high bit rate digital optical signals for telecommunications applications, comprising an optical amplifier and a photoreceiver diode. Generally, the two optical amplification and optical-electrical conversion functions are integrated in a common component, resulting in lower production costs, smaller footprint and improved reliability. To optimize the conversion device as a whole, it is demonstrated that there must be an active area of small thickness in the amplifier part and greater thickness in the conversion part. The invention proposes to implement this function by means of a structure comprising a diluted multimode waveguide common to the two amplification and reception sections, the first active area and the second area being disposed so as to ensure a coupling by evanescent waves with said diluted multimode waveguide.
1. An optoelectronic photoreception device for an optical signal comprising at least a structure with:
an optical amplification section comprising a first active area and,
a photoreception section comprising a second active area,
characterized in that said structure includes a multimode diluted waveguide common to both sections, the amplification and photoreception sections being separate, one side of the active area of the amplification section and one side of the active area of the photoreception section being in direct contact with said multimode diluted waveguide, the first active area and the second area being disposed so as to ensure a coupling by evanescent waves with said multimode diluted waveguide.
2. The device according to claim 1 , wherein the first active area has a thickness less than that of the second active area.
3. The device according to claim 1 , wherein the optical amplification section is of SOA type.
4. The device according to claim 1 , wherein the multimode diluted waveguide includes at least one stack of 2N layers that are thin, flat and parallel to each other, regularly alternating and with index numbers C i , the layers with an even index number being made of InP, the layers with an odd index number being made of InGaAsP.
5. The device according to claim 4 , wherein the number N is 5.
6. The device according to claim 4 , wherein the layers made of InGaAsP all have a thickness of approximately 0.16 microns.
7. The device according to claim 4 , wherein the layers made of InP have a thickness of between 0.36 microns and 0.66 microns.
8. The device according to claim 1 , wherein the multimode diluted waveguide includes an index tuning layer partly located under the active areas.
9. The device according to claim 8 , wherein said layer is made of InGaAsP.
10. The device according to claim 1 , wherein the first active area of the amplification section comprises a layer of GaInAs.
11. The device according to claim 1 , wherein the second active area of the photoreception section comprises a layer of GaInAs.
12. The device according to claim 3 , wherein the structure of the SOA includes at least two separate confinement heterostructures known by the acronym SCH, that are identical and located above and below the first active area.
13. The device according to claim 12 , wherein the separate confinement heterostructure is made of InGaAsP and has a thickness of 30 nanometres.