JPH0546704B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to an optical thyristor device that drives an optical thyristor element by making light incident thereon.

[Prior art and its problems]

It is well known that light-emitting diodes are used as light sources to drive optical thyristors, and light-emitting diodes are reliable and have a wide light pulse width that allows them to fire even when there is a delay in voltage rise. It is excellent in that it can be removed. However, the delay time when the optical thyristor is turned on depends on the magnitude of light input to the light receiving section, as shown in FIG. It is very difficult to obtain high energy with light emitting diodes, and the delay time is quite long.
In order to shorten the delay time, it is effective to perform overdrive at turn-on, which is a known technique for electric thyristors, but this is difficult for light-emitting diodes. Therefore, if a laser diode with high light output and good directivity is used as a light source, it is possible to
As is clear from the figure, the delay time can be shortened. However, although laser diodes can ensure sufficient light emitting output, they cannot ensure a sufficient pulse width because if the pulse width is lengthened, heat is generated internally, and the temperature rise due to this heat may cause the laser oscillation to stop. There is a drawback.

[Purpose of the invention]

Except for the above-mentioned disadvantages, the present invention provides an optical thyristor element equipped with a driving light source capable of injecting light with a sufficiently high energy and a duration necessary for ignition, which can be overdriven for ignition of the optical thyristor element. The purpose is to provide equipment.

[Key points of the invention]

According to the invention, a first optical fiber is coupled to a laser diode that generates a light pulse with a high peak value necessary for overdrive, and a light emitting diode that generates a light pulse that has a longer width than said light pulse. a second optical fiber coupled;
The first and second optical fibers are each connected to an input section, and a light pulse obtained by combining the light pulse from the first optical fiber and the light pulse from the second optical fiber is transmitted through a third optical fiber. The above object is achieved by coupling the output optical splitter and the third optical fiber to the light receiving section of the optical thyristor element.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a driving light receiving section of an optical thyristor device, which includes a light emitting diode 1 and a laser diode 2 as light sources. The light emitting diode 1 is connected to an optical fiber 7 via an optical coupler 3 having a lens 5.
The laser diode 2 is coupled to an optical fiber 8 via an optical coupler 4 having a lens 6. Optical fibers 7 and 8 are connected to one optical fiber 10 via an optical splitter 9. The other end of the optical fiber 10 is coupled to a light receiving portion of an optical thyristor element (not shown). The light from the light emitting diode 1 and the laser diode 2 are focused by lenses 5 and 6 in the optical coupler, respectively, and then connected to the optical fibers 7 and 6.
The light reaches the optical splitter 9 through the optical fiber 10, and enters the light receiving section of the optical thyristor element through the optical fiber 10. Generally, light from a light emitting diode has poor directivity compared to light from a laser diode, so the diameter of the optical fiber 7 connected to the optical coupler 3 is smaller than the diameter of the optical fiber 8 connected to the optical coupler 4. For example, the optical fiber 7 has a diameter of 0.3 mm compared to the diameter of the optical fiber 8 of 0.1 mm. The diameter of the optical fiber 10 connected to the optical splitter 9 is even larger, 0.45 mm. FIG. 3 shows an example of a time chart when an optical thyristor is driven by a light emitting diode and a laser diode using the light source section as shown in FIG. 1 according to the present invention. FIG. 3a shows the driving current 11 of the laser diode 2, and FIG. 3b shows the optical output 12 obtained at the end face of the optical fiber 10 when this driving current 11 is passed through the laser diode 2.
FIG. 3c shows the driving current 13 of the light emitting diode 1, and d shows the optical output 14 obtained at the end face of the optical fiber 10 when this driving current is passed through the light emitting diode 1. In this way, when the laser diode 2 and the light emitting diode 1 are made to emit light during the same time period, the optical fiber 10 connected after the optical splitter 9
The optical output 15 at the end face is as shown in FIG. 3e, and an optical gate pulse having a peak value of 120 mW, which is necessary for overdrive, is obtained. In other words, as shown in FIG.
The delay time shown at 21 can be shortened to the value shown at point 22 by using the laser diode 2 in combination.

【Effect of the invention】

By simultaneously using both a light emitting diode and a laser diode to drive an optical thyristor element, the present invention generates an optical pulse having a sufficient width necessary for reliable turn-on of the optical thyristor and a high peak value necessary for overdrive. It can be made incident on the thyristor element, and the delay time at turn-on can be reduced by almost half compared to the case of using only a light-emitting diode, and a short turn-on time can be secured, so the effect obtained is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the light source section of an embodiment of the present invention, Fig. 2 is a relationship diagram between light input to the optical thyristor and delay time at turn-on, and Fig. 3 is the same as shown in Fig. 1. This is a time chart of the light source drive current and light output when the optical thyristor using the light source section is ignited. 1... Light emitting diode, 2... Laser diode, 3, 4... Optical coupler, 7, 8, 10... Optical fiber, 9... Optical splitter.

Claims (1)

[Claims] 1 A first optical fiber coupled to a laser diode that produces light pulses with a high peak value required for overdrive, and a second optical fiber coupled to a light emitting diode that produces light pulses with a longer width than said light pulses. and the first and second optical fibers are connected to the input section, respectively, and the optical pulse obtained by combining the optical pulse from the first optical fiber and the optical pulse from the second optical fiber is connected to the input section. 1. An optical thyristor device comprising: an optical splitter that outputs output through three optical fibers; and the third optical fiber is coupled to a light receiving section of an optical thyristor element.