Light-emitting module
View Patent ↗A light-emitting module outputting laser beam emitted from a semiconductor light-emitting element via a lens, the light-emitting module includes a first main plane, a mount portion on the first main plane that mounts the semiconductor light-emitting element, a lens holding portion that holds the lens so that a light axis of the lens corresponds to a reference line crossed at right angles to the first main plane, a semiconductor light-receiving element that receives the laser beam reflected by the lens out of the laser beam emitted from the semiconductor light-emitting element. The semiconductor light-receiving element is positioned on the light axis of the lens and the semiconductor light-emitting element is provided away from the light axis of the lens.
1. A light-emitting module outputting laser beam emitted from a semiconductor light-emitting element via a lens, the light-emitting module comprising:
a first main plane;
a mount portion on the first main plane that mounts the semiconductor light-emitting element;
a lens holding portion that holds the lens so that a light axis of the lens corresponds to a reference line crossed at right angles to the first main plane;
a semiconductor light-receiving element that receives the laser beam reflected by the lens out of the laser beam emitted from the semiconductor light-emitting element;
wherein the semiconductor light-receiving element is positioned on the light axis of the lens and the semiconductor light-emitting element is provided away from the light axis of the lens such that an intensity of the laser beam emitted from the semiconductor light-emitting element is controlled based on the reflected laser beam received by the semiconductor light-receiving element.
2. The light-emitting module as claimed in claim 1 , wherein the semiconductor light-emitting element is deposited adjacently to the semiconductor light-receiving element on the first main plane of the mount portion.
3. The light-emitting module as claimed in claim 1 , wherein the lens is a ball lens.
4. The light-emitting module as claimed in claim 3 , wherein the semiconductor light-emitting element is provided within a range that does not exceed a radius of the ball lens from the light axis of the ball lens.
5. The light-emitting module as claimed in claim 1 , wherein the semiconductor light-receiving element is disposed on a second plane provided for mounting a member, on the first main plane of the mount portion.
6. The light-emitting module as claimed in claim 5 , wherein a distance from the first main plane to a light-receiving plane of the semiconductor light-receiving element is greater than that from the first main plane to a light-emitting plane of the semiconductor light-emitting element.
7. The light-emitting module as claimed in claim 1 , wherein the lens is capable of partially reflecting and partially transmitting the laser beam emitted from the semiconductor light-emitting element.
8. The light-emitting module as claimed in claim 7 , wherein a relationship of approximately A:B:C=7:7.5:2 is satisfied, where A is a distance from a lowermost face of the ball lens, B is a radius of the ball lens, and C is another distance from a center of a luminous point of the semiconductor light-emitting element.
9. The light-emitting module as claimed in claim 1 , wherein the semiconductor light-emitting element has a light-emitting profile showing a peak intensity at an angle tilted from the light axis of the lens.
10. The light-emitting module as claimed in claim 1 , wherein the semiconductor light-emitting element emits a multimode light.
11. The light-emitting module as claimed in claim 1 , wherein the semiconductor light-emitting element is a vertical cavity surface emitting laser diode.
12. An optical transmission apparatus comprising:
a light-emitting module; and
a transmission portion that transmits laser beam output from the light-emitting module through an optical fiber,
the light-emitting module outputting the laser beam emitted from a semiconductor light-emitting element via a lens, the light-emitting module including:
a first main plane;
a mount portion on the first main plane that mounts the semiconductor light-emitting element;
a lens holding portion that holds the lens so that a light axis of the lens corresponds to a reference line crossed at right angles to the first main plane;
a semiconductor light-receiving element that receives the laser beam reflected by the lens out of the laser beam emitted from the semiconductor light-emitting element;
wherein the semiconductor light-receiving element is positioned on the light axis of the lens and the semiconductor light-emitting element is provided away from the light axis of the lens such that an intensity of the laser beam emitted from the semiconductor light-emitting element is controlled based on the reflected laser beam received by the semiconductor light-receiving element.
13. The optical transmission apparatus as claimed in claim 12 , a light axis of the optical fiber is not aligned to that of the lens.
14. The optical transmission apparatus as claimed in claim 13 , the light axis of the optical fiber corresponds to a given angle showing a peak intensity of the semiconductor light-emitting element.
15. The optical transmission apparatus as claimed in claim 12 , further comprising a drive control portion that controls an output from the semiconductor light-emitting element on the basis of the output from the semiconductor light-receiving element.
16. A free space optical transmission apparatus comprising:
a light-emitting module; and
a transmission portion that transmits laser beam transmitted from the light-emitting module through free space,
the light-emitting module outputting the laser beam emitted from a semiconductor light-emitting element via a lens, the light-emitting module including:
a first main plane;
a mount portion on the first main plane that mounts the semiconductor light-emitting element;
a lens holding portion that holds the lens so that a light axis of the lens corresponds to a reference line crossed at right angles to the first main plane;
a semiconductor light-receiving element that receives the laser beam reflected by the lens out of the laser beam emitted from the semiconductor light-emitting element;
wherein the semiconductor light-receiving element is positioned on the light axis of the lens and the semiconductor light-emitting element is provided away from the light axis of the lens such that an intensity of the laser beam emitted from the semiconductor light-emitting element is controlled based on the reflected laser beam received by the semiconductor light-receiving element.
17. An optical transmission system comprising:
a light-emitting module; and
a transmission portion that transmits laser beam transmitted from the light-emitting module,
the light-emitting module outputting the laser beam emitted from a semiconductor light-emitting element via a lens, the light-emitting module including:
a first main plane;
a mount portion on the first main plane that mounts the semiconductor light-emitting element;
a lens holding portion that holds the lens so that a light axis of the lens corresponds to a reference line crossed at right angles to the first main plane;
a semiconductor light-receiving element that receives the laser beam reflected by the lens out of the laser beam emitted from the semiconductor light-emitting element;
wherein the semiconductor light-receiving element is positioned on the light axis of the lens and the semiconductor light-emitting element is provided away from the light axis of the lens such that an intensity of the laser beam emitted from the semiconductor light-emitting element is controlled based on the reflected laser beam received by the semiconductor light-receiving element.
18. A free space optical transmission system comprising:
a light-emitting module; and
a transmission portion that transmits laser beam transmitted from the light-emitting module through free space,
the light-emitting module outputting the laser beam emitted from a semiconductor light-emitting element via a lens, the light-emitting module including:
a first main plane;
a mount portion on the first main plane that mounts the semiconductor light-emitting element;
a lens holding portion that holds the lens so that a light axis of the lens corresponds to a reference line crossed at right angles to the first main plane;
a semiconductor light-receiving element that receives the laser beam reflected by the lens out of the laser beam emitted from the semiconductor light-emitting element;
wherein the semiconductor light-receiving element is positioned on the light axis of the lens and the semiconductor light-emitting element is provided away from the light axis of the lens such that an intensity of the laser beam emitted from the semiconductor light-emitting element is controlled based on the reflected laser beam received by the semiconductor light-receiving element.