OPTICAL TRANSMITTER AND METHOD OF MANUFACTURING THE SAME

1 . An optical transmitter comprising:

a substrate;

a light emitting element provided over said substrate; and

a temperature sensing element which measures temperature of said light emitting element, provided over said substrate,

said substrate having a recess provided in a surficial portion thereof, and

said light emitting element and said temperature sensing element being provided inside said recess.

2 . The optical transmitter as claimed in claim 1 ,

wherein said substrate has a plurality of said recesses provided in the surficial portion thereof.

3 . The optical transmitter as claimed in claim 1 ,

wherein said light emitting element and said temperature sensing element are provided inside the same recess.

4 . The optical transmitter as claimed in claim 2 ,

wherein said light emitting element and said temperature sensing element are provided inside the different recesses.

5 . The optical transmitter as claimed in claim 1 ,

wherein said recess has a bottom surface configured by a flat surface, and has side faces configured by a plurality of inclined surfaces inclined by a predetermined angle away from said flat surface.

6 . The optical transmitter as claimed in claim 1 , further comprising:

a trench provided in a surficial portion of said substrate in adjacent to said recess;

and a coupling lens which guides light output from said light emitting element to an optical fiber, provided to said trench.

7 . The optical transmitter as claimed in claim 6 ,

wherein said coupling lens has a cylindrical portion,

said trench has a bottom surface configured by a flat surface, and has side faces configured by a plurality of inclined surfaces inclined by a predetermined angle away from said flat surface,

said cylindrical portion being fixed between said inclined surfaces of said trench.

8 . The optical transmitter as claimed in claim 1 ,

wherein said substrate has the same thickness at a position where said light emitting element is disposed, and at a position where said temperature sensing element is disposed.

9 . The optical transmitter as claimed in claim 1 ,

wherein said light emitting element and said temperature sensing element are disposed so as to overlap with each other when viewed in the direction orthogonal to the optical axis of light.

10 . The optical transmitter as claimed in claim 1 ,

further comprising a monitoring photo diode inside said recess having said light emitting element disposed therein.

11 . The optical transmitter as claimed in claim 1 ,

further comprising an electronic cooling element which controls temperature of said light emitting element, provided over the lower surface of said substrate.

12 . The optical transmitter as claimed in claim 1 ,

wherein said recess is covered with a cover component, at the opening on the top surface of said substrate.

13 . The optical transmitter as claimed in claim 12 ,

wherein said cover component is composed of the same material with said substrate.

14 . The optical transmitter as claimed in claim 1 , further comprising an etalon provided inside said recess having said light emitting element disposed therein.

15 . The optical transmitter as claimed in claim 1 ,

wherein said substrate is composed of silicon.

16 . The optical transmitter as claimed in claim 1 ,

wherein said substrate has the top surface with (000) surface orientation.

17 . A method of manufacturing an optical transmitter comprising:

forming a mask layer over the top surface of a substrate, and forming, in said mask layer, an opening in which a part of the top surface of said substrate exposes;

removing, in said opening of said mask layer, said substrate by a predetermined depth, to thereby form a recess; and

providing, inside said recess, a light emitting element and a temperature sensing element.

18 . The method of manufacturing an optical transmitter as claimed in claim 17 ,

wherein in said forming said opening, a first opening and a second opening are formed side-by-side in said mask layer;

in said forming said recess, said substrate is anisotropically etched in said first opening to a predetermined depth D 1 to thereby form said recess, and said substrate is anisotropically etched in said second opening to a predetermined depth D 2 to thereby form a trench,

and the method further comprising providing a coupling lens inside said trench.

19 . The method of manufacturing an optical transmitter as claimed in claim 17 ,

wherein in said forming said opening, a plurality of said first openings are formed, to thereby form a plurality of said recesses.

20 . The method of manufacturing an optical transmitter as claimed in claim 18 ,

wherein said predetermined depth D 2 is made larger than said predetermined depth D 1 , by setting the dimension of said second opening larger than that of said first opening.

21 . The method of manufacturing an optical transmitter as claimed in claim 18 ,

wherein in said forming said opening(s), said mask layer is formed over the top surface of said substrate with (000) surface orientation, and forming, side-by-side in said mask layer, said first opening(s) and said second opening in which a part of the top surface of said substrate exposes, and

in said forming said recess(es), said substrate is anisotropically etched in said first opening(s) to a predetermined depth D 1 to thereby form said recess(es) having walls with (111) surface orientation and having a bottom with (000) surface orientation, and said substrate is anisotropically etched in said second opening to a predetermined depth D 2 to thereby form a trench having walls with (111) surface orientation, and having a bottom with (000) surface orientation.

22 . The method of manufacturing an optical transmitter as claimed in claim 17 ,

further providing an etalon inside said recess having said light emitting element disposed therein.

23 . The method of manufacturing an optical transmitter as claimed in claim 17 ,

further providing a monitoring photo diode inside said recess having said light emitting element disposed therein.

24 . The method of manufacturing an optical transmitter as claimed in claim 17 ,

wherein said recess are covered with cover component, at the opening on the top surface of said substrate.