Active solid-state devices (e.g. – transistors – solid-state diode – Incoherent light emitter structure – With housing or contact structure
Reexamination Certificate
1999-03-25
2001-05-22
Jackson, Jr., Jerome (Department: 2815)
Active solid-state devices (e.g., transistors, solid-state diode
Incoherent light emitter structure
With housing or contact structure
C372S045013
Reexamination Certificate
active
06236066
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a light emitting element and a method of manufacturing the same.
2. Related Background Art
Various kinds of light emitting elements have heretofore been utilized in various kinds of optical apparatuses; for example, in a printer apparatus or the like for forming images by an electrophotographic method, a semiconductor laser is utilized as a light emitting element for exposure. The semiconductor laser is generally formed in a thin film laminated structure, and a laser beam is induced and emitted in a lengthwise direction from a rectangular parallelepipedic laser resonator (stripe).
Such a semiconductor laser will hereinafter be described as an example of the light emitting element according to the prior art with reference to
FIGS. 1 and 2
of the accompanying drawings.
FIG. 1
is a typical perspective view showing the appearances of the semiconductor laser, and
FIG. 2
is a longitudinal cross-sectional view taken along the line
2
—
2
of FIG.
1
. Herein, longitudinal, left to right and vertical directions will be referred to with reference to
FIG. 1
, but these are conveniently used to simplify the description.
The semiconductor laser
1
exemplified as a light emitting element is provided with a laser resonator (stripe)
2
as a rectangular parallelepipedic light emitting portion elongated in a longitudinal direction (front-rear direction), as shown, and this laser resonator (stripe)
2
is enclosed in laser diode chip
3
which is a rectangular parallelepipedic enclosing portion flat in a vertical direction.
First and second electrode layers
6
and
7
are formed on a cathode surface
4
and an anode surface
5
, respectively, which are the two vertically opposed surfaces of the laser diode chip
3
, and the first electrode layer
6
is connected to a stem
8
, and the second electrode layer
7
has a bonding wire
9
connected thereto.
The laser resonator (stripe)
2
comprises, for example, GaAs or the like, and when electric power is supplied thereto in a vertical direction, it induces and emits a laser beam in a longitudinal direction which is a lengthwise direction. The laser diode chip
3
comprises, for example, GaAlAs or the like, and has electrical conductivity and a light transmitting property, and satisfactorily transmits a light beam, and is capable of direct radiation for satisfactorily observing an electron beam.
The first and second electrode layers
6
and
7
are formed of a metal such as Au, and electric power for causing the laser resonator (stripe)
2
to emit light is supplied thereto through the laser diode chip
3
. The bonding wire
9
and the stem
8
are formed of a metal such as Au and supply electric power for causing the laser resonator (stripe)
2
to emit light to the electrode layers
6
and
7
.
The semiconductor laser
1
of such structure as described above actually is disposed in a cylindrical package (not shown) by the stem
8
, and a driving circuit (not shown) is connected to the stem
8
and the bonding wire
9
through the connection terminal or the like of the package.
When in such a state, electric power is supplied from the driving circuit to the first and second electrode layers
6
and
7
of the semiconductor laser
1
through the bonding wire
9
and the stem
8
, this electric power is supplied to the laser resonator (stripe)
2
through the laser diode chip
3
and thus, this laser resonator (stripe)
2
induces and emits a laser beam in the forward direction, i.e., in a lengthwise direction.
The semiconductor laser
1
as described above induces and emits a laser beam from the laser resonator (stripe)
2
by supplying electric power to the first and second electrode layers
6
and
7
.
However, the semiconductor laser
1
as described above may suffer from the occurrence of the destruction or abnormality of the crystal in the laser resonator (stripe)
2
due to electrical stress such as static electricity or an external serge voltage. Also, if the time for which the semiconductor laser
1
is used is accumulated, the destruction or abnormality of the crystal may occur in the laser resonator (stripe)
2
.
So, when the semiconductor laser
1
is to be developed as a product, it is important to observe the state of the destruction or abnormality of the crystal of the laser resonator (stripe)
2
as described above and clear up the cause thereof and take an effective countermeasure. In this case, it is useful to actually supply electric power to the electrode layers
6
and
7
of the semiconductor laser
1
to thereby cause the laser resonator (stripe)
2
to emit light, and observe the dynamic state thereof by an optical microscope or an electronic microscope.
In the prior art semiconductor laser
1
, however, the laser diode chip
3
enclosing the laser resonator (stripe)
2
therein physically transmits a light beam well and is capable of direct radiation, but the electrode layers
6
and
7
formed on the upper and lower surfaces do not satisfactorily transmit a visible ray of light or an electron beam. Therefore, it is difficult to observe the laser resonator (stripe)
2
emitting light from the outside of the semiconductor laser
1
.
If, for example, the upper electrode layer
7
is peeled off, it is possible to observe the laser resonator (stripe)
2
from the outside by an optical microscope or an electronic microscope, but when the electrode layer
7
is peeled off, electric power cannot be supplied to the semiconductor laser
1
and therefore, the laser resonator (stripe)
2
emitting light cannot be dynamically observed.
In
FIGS. 1 and 2
, both sides of the laser diode chip
3
are opened, but these both sides are actually extremely narrow in width as compared with the upper and lower surfaces. In addition, each layer is laminated in a vertical direction, and therefore, it is actually difficult to observe the laser resonator (stripe)
2
from the sides of the laser diode chip
3
.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-noted problems, and the object thereof is to provide a light emitting element permitting the light emitting state of the light emitting portion thereof to be easily observed and a method of manufacturing the same.
The light emitting element of the present invention is a light emitting element provided with a light emitting portion emitting light by the supply of electric power thereto, an enclosing portion having electrical conductivity and having the light emitting portion enclosed therein, and first and second electrode layers formed on the two opposed surfaces of the enclosing portion and to which electric power for causing the light emitting portion to emit light is supplied, at least one of the first and second electrode layers being formed with an opening hole permitting the light emitting portion to be observed through the enclosing portion from a direction which is not affected by a beam emitted from the light emitting portion.
Accordingly, in the light emitting element of the present invention, when electric power is supplied to the first and second electrode layers, this electric power is supplied to the light emitting portion through the enclosing portion, and therefore, this light emitting portion emits light. Since at least one of the first and second electrode layers is formed with an opening hole by which the light emitting portion can be observed through the enclosing portion from a direction which is not affected by the beam emitted from the light emitting portion, the light emitting portion emitting light is observed from the outside of the opening hole.
As another embodiment of the invention in the light emitting element as described above, the light emitting portion comprises a laser resonator (stripe) which induces and emits a laser beam in a direction orthogonal to a direction in which electric power is supplied. Accordingly, the light emitting portion comprising a laser resonator (stripe) induces and emits a laser beam in an orthogonal direction when
Baumeister B. W.
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Jackson, Jr. Jerome
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