Optical device with integrated semi-conductor laser source and integrated optical isolator
View Patent ↗The field of the invention is that of optical devices comprising an integrated semi-conductor laser and an integrated optical isolator. These devices are used mainly in the field of digital telecommunications. More particularly, the invention applies to so-called absorption isolators whose complex index is non-reciprocal and depends on the direction of propagation of the light. Generally, integrated optical isolators of this type fulfill two functions. On the one hand, they comprise a magneto-optical layer ensuring the non-reciprocal effect and on the other hand an active zone ensuring the amplification of the laser beam, the injection of the charge carriers into the active zone being ensured by an electrical contact layer. The invention proposes, so as to limit the disturbing effects of the contact layer on the propagation of the laser beam, that the contact layer be eliminated above the active zone and that the injection of the charge carriers be ensured via the lateral faces and the edges of the upper face of the active zone.
1. An opto-electronic device comprising: an amplifying structure of SOA type having an optical isolator, said structure comprising:
a substrate made of n-doped semi-conductor material;
a stripe-shaped buried active zone having a lower face in contact with the substrate, an upper face and two lateral faces;
a p-doped vertical confinement layer positioned to cover the active zone and the substrate;
an electrical contact layer positioned above the p-doped vertical confinement layer and having a gap spaced above the active zone; and
a magneto-optical material layer positioned above the electrical contact layer;
wherein the active zone is configured to receive a current injection from the electrical contact layer only from the two lateral faces and edges of the upper face of the active zone.
2. The opto-electronic device according to claim 1 , wherein the gap of the contact layer having a width of about 1.5 times the width of the active zone.
3. The opto-electronic device according to claim 1 , further comprising a conducting layer positioned above the magneto-optical material layer.
4. The opto-electronic device according to claim 1 , further comprising a section having an emission source with semi-conductor laser with a buried stripe of BRS type, said section having at least one substrate, an active layer and a p-doped vertical confinement layer that are common to those of the amplifying structure, in such a way that the optical isolator ensures the isolation of said laser.
5. The opto-electronic device according to claim 1 , wherein the active zone comprises at least one MQW multiple quantum well structure.
6. The opto-electronic device according to claim 1 , wherein the thickness of the confinement layer situated above the active zone in the zone of the optical isolator equals about 0.3 microns.
7. The opto-electronic device according to claim 2 , wherein the active zone comprises at least one MQW multiple quantum well structure.
8. The opto-electronic device according to claim 3 , wherein the active zone comprises at least one MQW multiple quantum well structure.
9. The opto-electronic device according to claim 4 , wherein the active zone comprises at least one MQW multiple quantum well structure.
10. The opto-electronic device according to claim 2 , wherein the thickness of the confinement layer situated above the active zone in the zone of the optical isolator equals about 0.3 microns.
11. The opto-electronic device according to claim 3 , wherein the thickness of the confinement layer situated above the active zone in the zone of the optical isolator equals about 0.3 microns.
12. The opto-electronic device according to claim 4 , wherein the thickness of the confinement layer situated above the active zone in the zone of the optical isolator equals about 0.3 microns.
13. The opto-electronic device according to claim 5 , wherein the thickness of the confinement layer situated above the active zone in the zone of the optical isolator equals about 0.3 microns.