JPH0455833A - Optical switching device and method for driving optical switching device - Google Patents

Abstract

PURPOSE:To speed up operations by admitting address light, control signal light and information signal light as input signals in time series and generating a voltage by a driving synchronizing circuit when an address light detecting circuit detects the address light. CONSTITUTION:The voltage is generated from the driving synchronizing circuit 103 through a driving system 106 and a set pulse is impressed to a pnpn semiconductor element 201 when the address light detecting circuit 102 detects the address light 300. The voltage is generated from the driving synchronizing circuit 103 through the driving system 106 and a reset pulse is impressed to the pnpn semiconductor element 201 when the address light detecting circuit 102 detects the reset light 310. The problem that the operating speed cannot be increased to the on-off speed of the element or above, the problem that a power consumption increases and further the problem that the driving circuit is complicated in order to select as to whether the information signal is sent to the ensuing stage or not are solved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical switching device necessary for optical information processing and optical switching, and a method for driving the optical switching device.

(Prior art) Semiconductor elements that have the ability to change their internal state in response to minute trigger light and start emitting light, and continue to emit light even after the trigger light has disappeared, will be used in the construction of future optical information processing and optical switching systems. (indispensable) basic element. Figure 8 shows
Applied Physics.

Applied Physics Letts
ers) Magazine, Volume 54, Pages 329-331, 198
1 is a schematic diagram of a semiconductor optical device described in 1999. This element has a pnpn structure. The anode region and cathode region are each p-AI. ,4GaO,6A
Consisting of s8 etc., n-Alo, 4GaO, 6As2 etc.
These are n-Al0,25GaO,7A with narrow forbidden band width.
s7 n gate layer and p-Al0,25Ga□,75A
s3.1-AIo, 25GaO, 75As4.1-Ga
It has a structure sandwiching a p-gate layer made of As5, 1-Alo, 25GaO, and 75As6. This pnpn
The semiconductor element turns on, transitions from a high impedance state to a low impedance state, and as a result of carriers being confined in the gate region, light emission occurs. Furthermore, by setting the current flowing in this on state to a threshold value (100 mA in this device, 1 or more), this device emits stimulated emission light at a wavelength of 870 nm.The current-light output characteristics at that time are shown in Figure 9. The spectrum is shown in Figure 10. Figure 11 shows this p
A driving circuit diagram of an npn semiconductor element is shown. As shown in Fig. 11, a load resistor 30 and a power supply 31 are connected in series to the pnpn semiconductor element.
Connect. FIG. 12 shows a method for creating such a pnpn conductor element. As shown in FIG. 12(a), a positive voltage Vb (holding voltages vh, vb, switching voltage Vs) is applied from the power supply 31 to the anode electrode side.
A set pulse 60) and a negative voltage of Vr (reset pulse 66) are applied alternately. At this time, since Vb<■S, the pnpn semiconductor element cannot be turned on by voltage alone. In synchronization with this set pulse 60, an information signal light 62 is made incident as shown in FIG. 12(b). When the incident light is greater than the energy Ps required for switching, the pnpn semiconductor element turns on and emits light. Therefore, output signal light 63 corresponding to input signal light 62 was obtained. At this time, the load resistor 30 shown in FIG. 11 was selected so that the current flowing in the on state was equal to or higher than the threshold current. The element used here is Vs=5V, vh=1.5V, threshold current 100
mA, Ps=10pJ, Vb=4.5V, Vr
= -0.5V, and the load resistance was 27Ω.

Approximately 110 mA flows through the pnpn semiconductor element in the on state, and the optical output of the pnpn semiconductor element at that time is approximately 3 mW.
Met. Since the human power signal light 10 pJ was 1010n5X1, the amount of light was amplified nearly three times compared to the information signal light. While the set pulse 60 of FIG. 12(a) is being applied, optical output is obtained, and it functions as an optical memory and a switch.Furthermore, by using a plurality of manual light amounts, calculations such as AND operations can be performed. Furthermore, since the output light can be larger than the input light, an amplifier is not required when passing the signal to the next stage.

(Problem to be Solved by the Invention) In such a driving method, since the output is turned on and off by turning on and off the element, the on/off speed of the element (about several hundred Mb/s) or higher is Unable to increase operating speed. Furthermore, since it is necessary to switch the element each time, the optical energy Ps necessary for writing is required, which increases power consumption. Furthermore, in order to select whether or not to send the information signal to the next stage, it is necessary to change the power supply voltage or the signal strength depending on the input signal, resulting in the problem that the drive circuit etc. become complicated.

An object of the present invention is to provide a driving device and method for a pnpn semiconductor element that can operate at high speed, consumes low power, has a simple driving circuit, and has a large transmission capacity.

(Means for Solving the Problems) An optical switching device of the present invention branches an optical information transmission input line into a plurality of lines, and connects an address optical detection circuit to at least one of the plurality of optical information transmission input lines. connect and
A pnpn semiconductor element is connected to a line that is not connected to the address photodetection circuit among the plurality of branched optical information transmission input lines, and the address photodetection circuit and the drive synchronization circuit are connected through the first drive system. connecting the drive synchronization circuit and the pnpn semiconductor element through a second drive system, connecting an optical information transmission output line to the pnpn semiconductor element, and driving the pnpn semiconductor element with the drive synchronization circuit. It is characterized by

Alternatively, the optical switching device of the present invention is the optical switching device described above, in which the drive synchronization circuit and a plurality of p
The present invention is characterized in that the npn semiconductor elements are connected through a second drive system, and the plurality of pnpn semiconductor elements are driven in time series by the one drive synchronization circuit.

Alternatively, the optical switching device of the present invention may include the pnp
The n semiconductor element has an anode region made of a p-type semiconductor and an n
A cathode region made of a type semiconductor sandwiches a gate region made of a plurality of semiconductor layers narrower than the forbidden band width of the anode region and cathode region, and emits stimulated emission light in a low impedance state.

A method for driving an optical switching device according to the present invention includes a step of irradiating address light having timing information for applying a voltage to the pnpn semiconductor element of the optical switching device, and a control signal for setting the operating state of the pnpn semiconductor element. a step of irradiating light, a step of irradiating information signal light, a step of irradiating reset light, a step of detecting the address light by the address light detection circuit, and a step of detecting the address light by the drive synchronization circuit. a step of applying a positive voltage between the anode and cathode of the pnpn semiconductor layer at a timing according to the information contained in the pnpn semiconductor layer; a step of detecting the reset light; and a step of detecting the reset light by the synchronous drive circuit. The method is characterized by comprising a step of applying a negative voltage between the anode and cathode of the pnpn semiconductor element at a timing corresponding to the pnpn semiconductor element.

Alternatively, the method for driving an optical switching device of the present invention includes:
A step of irradiating address light having information on the timing of applying a voltage to the pn and pn semiconductor layers of the optical switching device and the magnitude of the applied voltage, and a step of irradiating a control signal light that sets the operating state of the pnpn semiconductor element. a step of irradiating wavelength-multiplexed information signal light; a step of irradiating reset light; a step of detecting the address light by the address light detection circuit; A step of applying a positive voltage between an anode and a cathode in accordance with the information contained in the address light to the element; a step of selecting only the information signal light of the wavelength; a step of detecting the reset light; The method is characterized by comprising a step of applying a negative voltage.

Alternatively, the method for driving an optical switching device of the present invention includes:
The method for driving the optical switching device is characterized in that the intensity of the voltage generated by the drive synchronization circuit in synchronization with the control signal light is greater than the voltage generated by the drive synchronization circuit in response to the information signal first input. Features.

(Function) In the off state, the pnpn semiconductor element only absorbs light,
In the on state, light is amplified by intracavity gain.

Utilizing this, it outputs light while amplifying light in the on state, but absorbs light in the off state, making it possible to not generate high power.

If a voltage higher than the holding voltage is applied while the pnpn semiconductor element is turned on by inputting the control signal light, a current flows through the pnpn semiconductor element, and the value of this current can be controlled by the applied voltage. FIG. 15 is a diagram showing current-voltage characteristics of a pnpn semiconductor element. It can be seen that the current flowing through the element when the element is turned on changes depending on the applied voltage. If the voltage is set so that this current has a value below the oscillation threshold, the pnpn semiconductor element functions as an optical amplifier. By arranging multiple such elements,
By adjusting the timing of the voltage applied to each pnpn semiconductor element, it is possible to select from which pnpn semiconductor element output light is extracted, and a self-routing switch or a spatial modulator can be configured. At this time, if there is reflection on both end faces of the element, it operates as a resonant optical amplifier that selectively amplifies light only at the resonant wavelength, and the resonant wavelength is determined by the isolateral refractive index of the element and the resonator length. It's decided. Since the isolateral refractive index of the element changes according to the current value due to the plasma effect, the resonance wavelength can be controlled by the current (voltage). FIG. 16 is a diagram showing a change in resonance wavelength due to a current flowing through a pnpn semiconductor element. The resonance wavelength changes to the shorter wavelength side as the current increases at a rate of about 1 person/mA due to the plasma effect. From the above, pnp
irradiating the n semiconductor element with wavelength-multiplexed information signal light,
If only the information signal light of a desired wavelength is selected by the applied voltage, it is possible to identify even when a plurality of signals of different wavelengths are incident simultaneously, and the degree of signal multiplexing is determined by the number of selected wavelengths. Therefore, the degree of multiplexing of signals is not limited by the switching speed of the elements, which not only increases the amount of transmitted information, but also eliminates the need for a device for timing adjustment between signal units, simplifying the device. Also, Fig. 13(a)
Even when time-division multiplexing transmission is performed using the pnpn element driving method shown in ~(e), the multiplicity of the system is determined by the product of the time multiplicity and the wavelength multiplicity, so it is necessary to increase the transmission capacity. Leads to.

In order to realize the above functions, it is necessary to apply a voltage to the pnpn semiconductor element in synchronization with the control signal light.

One possible method for this purpose is to prepare one transmission line for transmitting information for voltage generation to the drive circuit and arrange it in parallel with the optical information transmission input line, as shown in FIG. This method naturally requires two transmission lines: one for transmitting optical information and one for transmitting information for generating voltage. Since the optical information and the information for voltage generation are transmitted through separate transmission lines, a problem arises in that the circuit for adjusting the timing of the optical signal and the electrical signal (voltage) becomes complicated. Therefore, in the optical switching device and driving method of the present invention, address light is placed before the control signal light, and when the address light detection circuit detects the address light, a voltage is generated by the drive synchronization circuit. As a result, only one signal line for transmitting optical information is required as a transmission line, and the circuit for timing adjustment is simplified. Furthermore, by providing the address light with information on the shape and magnitude of the applied voltage, it is possible to easily select only the information signal light of a desired wavelength from among the wavelength-multiplexed information signal lights.

(Example) Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an embodiment of an optical switching device of the present invention. FIG. 2 is a diagram showing another embodiment of the optical switching device of the present invention.

The present invention will be explained using FIG. 1, but the basic operation is the same in the case of FIG.

As shown in FIG. 1, address light 300 and control signal light 40
0, information signal light 410, and reset light 310 are sequentially pnp
The n-semiconductor element 201 was irradiated. pnpn used in the experiment
The semiconductor element 201 was the same as that used in the conventional example (FIG. 8). The address light detection circuit 102 detects the address light 30
0 is detected, the drive synchronization circuit 1 is activated through the drive system 106.
A voltage is generated from 03 and pnpn is generated through the drive system 107.
A set pulse was applied to the semiconductor element 201. Further, when the address light detection circuit 102 detects the reset light 310, a voltage is generated from the drive synchronization circuit 103 through the drive system 106, and the voltage is generated through the drive system 107 to the pnpn semiconductor element 2.
A reset pulse was applied to 01. In this case, the pnpn semiconductor element 201 does not turn on with only the applied voltage, and the control signal light 400 (wavelength 870 nm, optical energy of Ps or higher) is applied to the pnpn semiconductor element 201 at the same timing as the set pulse.
Only when the light was incident on the npn semiconductor device, the device was turned on, and a current accordingly flowed through the device. While applying the set pulse to the device, the pnpn semiconductor device has a
A current of mA flows, and since the current is below the oscillation threshold current of the element, oscillation does not occur, and the light emitted from the element itself is very small. When the element in the on state was irradiated with information signal light 410 having a wavelength λ□=870.0 nm, the information signal light was emitted. Here, the intensity of the information signal light is made smaller than the intensity of the control signal light, which is a necessary condition for turning on the element with the control signal light but not turning on the element with the information signal light.

FIG. 3 shows a first embodiment of the method for driving the optical switching device of FIG. 1. In FIG. As shown in FIG. 3(a), address light 300, control signal light 400, information signal light 410, and reset light 310 were sequentially irradiated onto pnpn semiconductor element 201. PNPN semiconductor device 2 used in the experiment
01 was the same as the element shown in FIG. When the address light detection circuit 102 detects the address light 300, the drive system 106
A voltage is generated from the drive synchronization circuit 103 through the drive system 107, and a set pulse (voltage Vl = 4.0V) is applied to the pnpn semiconductor element 201 through the drive system 107, as shown in FIG.
)70 was applied.

Further, when the address light detection circuit 102 detects the reset light 310, the drive synchronization circuit 103 passes through the drive system 106.
A reset pulse (voltage Vr=-0,5V
)90 was applied. In this case, with only applied voltage, pnp
The control signal light 400 (
A wavelength of 870 nm, a light energy of Ps or more) is applied to the pn and pn semiconductor elements 2 at the same timing as the set pulse.
01, the element was turned on, and accordingly, a current flowed through the element 201 as shown in FIG. 3(C).

While a set pulse is being applied to the device, a current of 90 mA flows through the pnpn semiconductor device, and since the current is below the oscillation threshold current of the device, no oscillation occurs, and the light emitted from the device itself is very small. Wavelength λ1 = 870.0 for the element in the on state
When irradiated with information signal light 410 nm, the wavelength λ1 == which matches the resonant wavelength is generated by an operation similar to that of a laser amplifier.
870. Onm information signal light 510 was emitted as shown in FIG. 3(d). Here, the intensity of the information signal light is /J) lower than the intensity of the control signal light, and this is a necessary condition in order to turn on the element with the control signal light, but not with the information signal light. .

Figure 4 shows the second method of driving the optical switching device shown in Figure 1.
It is a figure showing an example of. As shown in FIG. 4(a), address light 300, control signal light 400, information signal light 4
10. The reset light 310 is sequentially applied to the pnpn semiconductor device 20
1 was irradiated. PNPN semiconductor device 201 used in the experiment
was the same as the element shown in FIG. Address light detection circuit 10
2 detects the address light 300, a voltage is generated from the drive synchronization circuit 103 through the drive system 106, and the drive system 107
Set pulse 71 to the pnpn semiconductor element 201 through
was applied. Here, the address light 300 has information on the magnitude and shape of the applied voltage, and as shown in FIG. 4(b), the voltage at the beginning of the set pulse 71 (corresponding to when the control light is incident) is higher than at the later part. That's what I do. Furthermore, when the address light detection circuit 102 detects the reset light 310,
A voltage is generated from the drive synchronization circuit 103 through the drive system 106, and the pnpn semiconductor element 201 is generated through the drive system 107.
A reset pulse (voltage Vr = -0.5V) 90 was applied to.

In this case, the pnpn semiconductor element does not turn on with only the applied voltage, and the control signal light 400 (wavelength 870 nm, light energy of Ps or higher) is used as a set pulse as shown in FIGS. 4(a) and (b). pnp at the right time
By entering the H semiconductor element, the element was turned on, and accordingly, a current of 110 mA flowed through the element. At this time, the cent pulse 71 changes the applied voltage when the control signal light is incident to 4
, 5V, and the applied voltage (4, OV) when the information signal light is incident.
It was set to be higher than that. As a result, Figure 4 (
As shown in e), a threshold current of 100 is applied to the pn and pn semiconductor elements.
Because a current larger than mA flows through it, it oscillates and begins to emit light on its own. As shown in FIG. 4(d), a control signal light 500 having an optical output of approximately 3 mW was obtained. When the information signal light is incident, only 90 mA of current flows through the pnpn semiconductor element, and since it is below the oscillation threshold current of the element, oscillation does not occur, and the wavelength λ1 matching the oscillation wavelength is generated by the same operation as a laser amplifier.
=870. Onm output information signal light 510 was emitted.

Figure 5 shows the third method of driving the optical switching device shown in Figure 1.
It is a figure showing an example of. As shown in FIG. 5(a), address light 300, control signal light 400, information signal light 4
11 (wavelength λ1 = 87 (10 nm), information signal light 4
12 (wavelength λ2 = 870.2 nm), reset light 3
10. The pnpn semiconductor element 201 was sequentially irradiated with address light 301, control signal light 400, and information signal light 411 and 412. The pnpn semiconductor element 201 used in the experiment was the eighth
It was the same as the element shown in the figure. Information on the magnitude of the applied voltage is given to the address light itself, and when the address light detection circuit 102 detects the address light 300, a voltage is generated from the drive synchronization circuit 103 through the drive system 106, and the voltage is generated through the drive system 107 to the pnpn semiconductor element. A set pulse 80 (voltage 4.OV) was applied to 201 as shown in FIG. 5(b).

Further, when the address light detection circuit 102 detects the reset light 310, the drive synchronization circuit 103 passes through the drive system 106.
A reset pulse (voltage Vr=-0,5
V) 90 was applied. Next, address light detection circuit 1
02 detects the address light 301, a voltage is generated from the drive synchronization circuit 103 through the drive system 106, and the drive system 1
A set pulse 81 (voltage 3.9 V) was applied to the pnpn semiconductor element 201 through 07. Here, since the information of the address lights 300 and 301 is different, the voltage values of the set pulse voltages 80 and 81 are different. In this case, the pnpn semiconductor element cannot be turned on by only the applied voltage, and as shown in FIG.
The device was turned on by entering the pnpn semiconductor device with light energy of more than m, Ps at the same timing as the set pulse, and a current flowed through the device as shown in FIG. 5(C). When the information signal light is input, when a set pulse of 80 is applied to the pnpn semiconductor element, only a current of 90 mA flows, and since it is below the oscillation threshold current of the element, oscillation does not occur, and the operation similar to that of a laser amplifier matches the resonant wavelength. Wavelength Sue=870. Only the On, m output information signal light 511 was emitted as shown in FIG. 5(d). Furthermore, when the set pulse 81 is applied to the pnpn semiconductor device, only a current of 88 mA flows, which is below the oscillation threshold current of the device, so oscillation does not occur, and the wavelength λ2 = matching the resonance wavelength due to the same operation as a laser amplifier. 87
Only the 0.2 nm output information signal light 512 was selectively amplified.

FIG. 6 shows the fourth method of driving the optical switching device shown in FIG.
It is a figure showing an example of. As shown in FIG. 6(a), address light 300, control signal light 400, information signal light 4
11 (wavelength 870.On'm), information signal light 412 (wavelength 870.2 nm), reset light 310, address light 3
01, control signal light 400, and information signal light 411 and 412 were sequentially irradiated onto the pnpn semiconductor element 201. The pnpn semiconductor device 201 used in the experiment was similar to the device shown in FIG. Information on the magnitude of the applied voltage is given to the address light itself, and when the address light detection circuit 102 detects the address light 300, the address light is sent to the drive synchronization circuit 103 through the drive system 106.
A set pulse 82 (4.5V when the control signal light is incident, 4.OV when the information signal light is incident) is generated from
) was applied. Furthermore, when the address light detection circuit 102 detects the reset light 310, a voltage is generated from the drive synchronization circuit 103 through the drive system 106, and a reset pulse (voltage Vr=-0,5V )90 was applied. Subsequently, when the address light detection circuit 102 detects the address light 301,
A voltage is generated from the drive synchronization circuit 103 through the drive system 106, and the pnpn semiconductor element 201 is generated through the drive system 107.
A set pulse 83 (4.5 V when the control signal light is incident, 3.9 V when the information signal light is incident) was applied to the. In this case, the pnpn semiconductor element cannot be turned on only by the applied voltage, and as shown in FIG.
By injecting a light energy of 0 nm, Ps or more into the pnpn semiconductor element at the same timing as the cent pulse, the element was turned on, and a current accordingly flowed through the element. Set pulse 82 as shown in FIG. 6(C)
．． By setting the voltage applied when the control signal light of 83 is 4.5V, which is higher than the voltage applied when the information signal light enters, a current of 110mA, which is larger than the threshold current of 100mA, flows through the pnpn semiconductor element, causing oscillation. Then, it began to emit light on its own. As shown in FIG. 6(d), a control signal light 500 with an optical output of about 3 mA was obtained at this time. When the set pulse 82 is applied to the pnpn semiconductor element when the information signal light is incident, only a current of 90 mA flows, and since it is below the oscillation threshold current of the element, oscillation does not occur, and the resonant wavelength is matched by an operation similar to that of a laser amplifier. Wavelength λ□=870. Only Onm output information signal light 511 was emitted. In addition, when the set pulse 83 is applied to a pnpn semiconductor element, only a current of 88 mA flows when the information signal light is incident, and oscillation does not occur because the oscillation threshold current of the element is lower than the oscillation threshold current, and resonance occurs due to the same operation as a laser amplifier. Wavelength λ2 that matches the wavelength = 870
．． Only the 2 nm output information signal light 512 was selectively amplified.

FIG. 2 is a diagram showing another embodiment of the optical switching device of the present invention. The basic function and operating principle of the device is the same as the device 3' in FIG. 1, except that FIG. 2 has two pn and pn elements and associated wiring.

A fifth embodiment of the present invention will be described using FIGS. 2 and 7. Figure 7 is a diagram for explaining the driving method.
In the case of the pnpn element 201, a) to (d) are (e) to (
h) shows the case of element 202. Address light 300, control signal light 400, information signal light 410, reset light 310
were sequentially irradiated onto the pnpn semiconductor elements 201 and 202.

The pnpn semiconductor elements 201 and 202 used in the experiment were the 8th
When the address light detection circuit 102, which is similar to that shown in the figure, detects the address light 300, a voltage is generated from the drive synchronization circuit 103 through the drive system 106, and set pulses are applied to the pnpn semiconductor elements 201 and 202 in time series through the drive system 107 and 108. , voltage Vl = 4.0V) 72.73 were applied, respectively. Further, when the address light detection circuit 102 detects the reset light 310, a voltage is generated from the drive synchronization circuit 103 through the drive system 106, and a reset pulse (voltage V
r = −0,5 V) 90 was applied.

The timing of the applied voltage and the incident light is determined by the pnpn element 201.
The case of the pnpn element 202 is shown in FIGS. 7(a) and 7(b), and the case of the pnpn element 202 is shown in FIG. Only the pnpn semiconductor element 201 to which the control signal light 400 (wavelength: 870 nm, light energy of Ps or higher) is incident in accordance with the information of the address light 300 and is timed to the set pulse is turned on, and accordingly, as shown in FIG.
), a current flowed as shown in In the pnpn element 202, as shown in FIG. 7(0), the set pulse 73 is delayed in time compared to the set pulse 72 due to the information of the address light, so the timing does not match with the control signal light 400, No current flows as shown in g), therefore, as shown in Fig. 7 (h)
(No light is emitted twice. While a set pulse is applied to the pnpn element 201 that is in the on state, a current of 90 mA flows through the element, and since this is less than the oscillation threshold current of the element, no oscillation occurs. , the light emission from the element itself is very l'
·shellfish.

Wavelength λ1=870 for pnpn semiconductor elements 201 and 202
．． When the information signal light 410 of 0 nm was irradiated, the information signal light 510 was emitted only from the element 201 which was in the on state as shown in FIG. 7(d). In this way, the address light causes only a specific element to emit light, thereby making it possible to transmit information.

Although this embodiment shows an example using two pnpn semiconductor elements, by further increasing the number of elements, a larger amount of information can be transmitted.

In the first and third embodiments of the method for driving an optical switching element, the control signal light is absorbed into the element and disappears, or the amount of light is insufficient to switch the next stage element, and the information is lost. Before passing the signal over many stages, it is necessary to add a control signal light by some method each time.
In the second and fourth embodiments, the control signal can be generated by the light emission of the element itself. The reason why the set pulse applied to the element is applied in two stages is a necessary condition so that even in the same on state, oscillation occurs when the control signal light is incident, and oscillation does not occur when the information signal light is incident.

By using the optical switching device and its driving method shown in this example, high-speed transmission of IGb/s can be achieved with a simple driving circuit and low power consumption. Furthermore, the capacity can be further increased by using wavelength multiplexing. For example, if 10 wavelengths are multiplexed, transmission of 10 Gb/s is possible.

(Effects of the Invention) This invention relates to an optical switching device and a method for driving an optical switching device that can be applied to optical information processing and optical switching, in which address light, control signal light, and information signal light are input in time series as human signals, and address light is By configuring the drive synchronization circuit to generate a voltage when the photodetector circuit detects the address light, it solves the problem of not being able to increase the operating speed beyond the on/off speed of the element, and the problem of increased power consumption. This solves the problem of complicating the drive circuit in order to select whether or not to send the information signal to the next stage.Also, by irradiating the PNPN semiconductor element with wavelength-multiplexed information signal light, the address light can be By controlling the applied voltage based on the information held and selecting only the information signal light of the desired wavelength,
Transmission capacity could be easily increased.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of an optical switching device of the present invention. FIG. 2 is a diagram showing another embodiment of the optical switching device of the present invention. FIGS. 3(a) to 3(d) are diagrams showing a first embodiment of the method for driving an optical switching device of the present invention. FIGS. 4(a) to 4(d) are diagrams showing a second embodiment of the method for causing trouble in an optical switching device according to the present invention. FIGS. 5(a) to 5(d) are diagrams showing a third embodiment of the method for driving an optical switching device of the present invention. Figure 6 (
a) to (d) are diagrams showing a fourth embodiment of the method for driving an optical switching device of the present invention. Figure 7 (a) to (h)
) is a diagram showing a fifth embodiment of the method for driving an optical switching device of the present invention. FIG. 8 is a perspective view of the device, FIG. 9 is a current-light output characteristic diagram of the device, FIG. 10 is a diagram showing an oscillation spectrum, and FIG. 11 is a diagram showing a conventional device and circuit.
12(a) to (C) and FIG. 13(a) to (C) are diagrams each showing a conventional driving method, FIG. 14 is a diagram showing an example of a driving method, and FIG. 15 is a diagram showing a conventional driving method. The current-voltage characteristic diagram of the element, FIG. 16, is a diagram showing the relationship between current and resonance wavelength. 1 is n-GaAs substrate, 2 is n-Al□, 4Ga□, 6
As, 3 is p-Al0,25Ga□, 75As, 4 and 6 are 1-AIo, 25Gao, 75As15 is 1-G
aAs, 7 is n-A1.0, 25Ga□, 75As, 8
is p-AI□, 4Ga□, 6As, 9 is p-GaAs,
10 is a p-type electrode, 11 is an n-type electrode, 12 is a pnpn semiconductor element, 30 is a load resistor, 31 is a power source, 32 is input light, 33 is output light, 60 and 70.71.72.73.
80.81.82.83 are set pulses, 66 and 90
is a reset pulse, 101 is an optical information input transmission line, 102
103 is an address light detection circuit, 103 is a drive synchronization circuit, and 104 is an address light detection circuit.
105 is a branch optical signal line, 105 is an optical information output transmission line, and 106.
107.108 is a drive system, 201.202 is a pnpn semiconductor element, 300.301 is an address light, 310 is a reset light, 400 is a control signal light, 62 and 410.411
．． 412 is information signal light, 6;l is output signal light, 500 is control signal (output) light, and 510.511.512 is information signal (output) light.

Claims (6)

[Claims] (1) An optical information transmission input line branched into a plurality of lines, an address photodetection circuit connected to at least one of the optical information transmission input lines, and an optical information transmission input line branched into the plurality of lines. Among them, a pnpn semiconductor element connected to a line not connected to the address photodetection circuit, a drive synchronization circuit connected to the address photodetection circuit via a first drive system, and the drive synchronization circuit. An optical switching device comprising: a second drive system connecting the pnpn semiconductor element; and an optical information transmission output line connected to the pnpn semiconductor element. (2) The optical switching device according to claim 1, wherein the drive synchronization circuit and a plurality of pnpn semiconductor elements are connected via a second drive system, and the one drive synchronization circuit connects the plurality of pnpn semiconductor elements. An optical switching device characterized in that elements are driven in time series. (3) The optical switching device according to claim 1 or 2, wherein the pnpn semiconductor element has an anode region made of a p-type semiconductor and a cathode region made of an n-type semiconductor in a forbidden band of the anode region and the cathode region. An optical switching device sandwiching a gate region made of a plurality of semiconductor layers narrower than the width, and emitting stimulated emission light in a low impedance state. (4) irradiating the pnpn semiconductor element with address light having timing information for applying voltage;
A step of irradiating a control signal light that sets the operating state of the pn semiconductor element, a step of irradiating an information signal light, a step of irradiating a reset light, a step of detecting the address light by an address light detection circuit, and a step of driving. A synchronous circuit detects the pnp at a timing according to information contained in the address light.
a step of applying a positive voltage between the anode and cathode of the n-semiconductor element; a step of detecting the reset light; A method for driving an optical switching device, comprising: applying a negative voltage between an anode and a cathode. (5) a step of irradiating the pnpn semiconductor element with address light having information on the timing of applying a voltage and the magnitude of the applied voltage; and a step of irradiating a control signal light that sets the operating state of the pnpn semiconductor element; A step of irradiating wavelength-multiplexed information signal light, a step of irradiating reset light, a step of detecting the address light by an address light detection circuit, and a step of detecting the address light by a drive synchronization circuit. a step of applying a positive voltage between the anode and cathode of the pnpn semiconductor element accordingly; and applying the positive voltage to only the information signal light of a desired wavelength from the wavelength-multiplexed information signal light. a step of selecting the reset light, a step of detecting the reset light, and a step of the drive synchronization circuit detecting the p
A method for driving an optical switching device, comprising the step of applying a negative voltage between an anode and a cathode of an npn semiconductor element. (6) The method for driving an optical switching device according to claim 4 or 5, wherein the intensity of the voltage generated by the drive synchronization circuit in synchronization with the control signal light is such that the intensity of the voltage generated by the drive synchronization circuit when the information signal light is incident is A method for driving an optical switching device, characterized in that the voltage is higher than the voltage generated by a synchronous circuit.