Surface emitting semiconductor laser array and optical transmission system using the same

1. A surface emitting semiconductor laser array comprising

multiple light-emitting portions arranged in a one-dimensional or two-dimensional array, each of the light-emitting portions including, on a substrate, an active region and a current funneling portion between first and second reflection mirrors, and a light-emission aperture above the second reflection mirror, laser beams being simultaneously emitted from the multiple light-emitting portions,

at least one of the multiple light-emitting portions having a plurality of electrodes that define a light-emission aperture having a center that is displaced from a center of an oxidization-based aperture in the current funneling portion.

2. The surface emitting semiconductor laser array as claimed in claim 1 , wherein said at least one of the multiple light-emitting portions is located at an end of the array.

3. The surface emitting semiconductor laser array as claimed in claim 1 , wherein centers of light-emitting portions among the multiple light-emitting portions located at an end of the array is displaced from centers of oxidization-based apertures towards a center of the array.

4. The surface emitting semiconductor laser array as claimed in claim 1 , wherein:

the multiple light-emitting portions include posts formed on the substrate;

the light-emission aperture is formed on a top of each of the posts; and

an oxidization-based aperture is formed in the current funneling portion in each of the posts.

5. The surface emitting semiconductor laser array as claimed in claim 4 , wherein the current funneling portion includes an AlAs layer, and the oxidization-based aperture is formed by selective oxidization of the AlAs layer from a side surface of each of the posts.

6. The surface emitting semiconductor laser array as claimed in claim 1 , wherein the light-emission aperture is formed in an electrode layer via which current is injected to a corresponding one of the multiple light-emitting portions.

7. The surface emitting semiconductor laser array as claimed in claim 1 , wherein the light-emission aperture includes one of a single layer and a multi-layer reflection film.

8. The surface emitting semiconductor laser array as claimed in claim 1 , wherein the laser beams emitted from the multiple light-emitting portions are combined into a single light signal.

9. A module comprising:

a semiconductor chip on which a surface emitting semiconductor laser array is mounted,

the surface emitting semiconductor laser array including:

multiple light-emitting portions arranged in a one-dimensional or two-dimensional array, each of the light-emitting portions including, on a substrate, an active region and a current funneling portion between first and second reflection mirrors, and a light-emission aperture above the second reflection mirror, laser beams being simultaneously emitted from the multiple light-emitting portions,

at least one of the multiple light-emitting portions having a plurality electrodes that define a light-emission aperture having a center that is displaced from a center of an oxidization-based aperture in the current funneling portion.

10. A surface emitting semiconductor laser device comprising:

a module having a semiconductor chip on which a surface emitting semiconductor laser array is mounted; and

a driver circuit supplying the surface emitting semiconductor laser array with a drive signal,

the surface emitting semiconductor laser array including:

multiple light-emitting portions arranged in a one-dimensional or two-dimensional array, each of the light-emitting portions including, on a substrate, an active region and a current funneling portion between first and second reflection mirrors, and a light-emission aperture above the second reflection mirror, laser beams being simultaneously emitted from the multiple light-emitting portions,

at least one of the multiple light-emitting portions having a plurality of electrodes that a light-emission aperture having a center that is displaced from a center of an oxidization-based aperture in the current funneling portion.

11. An optical transmission apparatus comprising:

a module having a semiconductor chip on which a surface emitting semiconductor laser array is mounted; and

a transmission unit transmitting laser light emitted from the surface emitting semiconductor laser array,

the surface emitting semiconductor laser array including:

multiple light-emitting portions arranged in a one-dimensional or two-dimensional array, each of the light-emitting portions including, on a substrate, an active region and a current funneling portion between first and second reflection mirrors, and a light-emission aperture above the second reflection mirror, laser beams being simultaneously emitted from the multiple light-emitting portions,

at least one of the multiple light-emitting portions having a plurality of electrodes that define a light-emission aperture having a center that is displaced from a center of an oxidization-based aperture in the current funneling portion.

12. The optical transmission apparatus as claimed in claim 11 , wherein the transmission unit transmits the laser light using free space optical transmission.

13. An optical transmission system comprising:

a module having a semiconductor chip on which a surface emitting semiconductor laser array is mounted; and

a transmission unit transmitting laser light emitted from the surface emitting semiconductor laser array,

the surface emitting semiconductor laser array including:

multiple light-emitting portions arranged in a one-dimensional or two-dimensional array, each of the light-emitting portions including, on a substrate, an active region and a current funneling portion between first and second reflection mirrors, and a light-emission aperture above the second reflection mirror, laser beams being simultaneously emitted from the multiple light-emitting portions,

at least one of the multiple light-emitting portions having a plurality of electrodes that define a light-emission aperture having a center that is displaced from a center an oxidization-based aperture in the current funneling portion.

14. The optical transmission system as claimed in claim 13 , wherein the transmission unit transmits the laser light using free space optical transmission.