JPH0797194B2 - Optical signal shift circuit - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical signal shift system which is used as a logical operation device in an optical computer or the like and shifts an optical data signal according to an electric clock signal.

(Prior art and its problems) Conventionally, as a device for performing a logical operation of an electric signal at high speed, a current mode logic having a current switch as a basic block is known, and more recently, a GaAs FET, a Josephson coupling element, etc. Research on ultra-high-speed logic operation devices using IPS is ongoing.

However, there is a limit in terms of calculation speed, power consumption, and the like for performing high-speed digital information processing of a large amount of two-dimensional data such as image information using electric signals. Therefore, it is desired to realize an optical logic operation device capable of digitally processing an optical signal as it is, which has an affinity for parallel processing of two-dimensional information at high speed. An optical shift register that can shift information is indeterminate.

Therefore, an object of the present invention is to provide an optical signal shift system capable of shifting an optical data signal according to an electric clock signal.

(Means for Solving the Problems) According to the present invention, the first and second electrodes are arranged apart from each other in the resonance axis direction and are supplied from the first electrode.
Of the first injection current and the amount of emitted light, and between the second injection current supplied from the second electrode and the amount of emitted light, and first and second hysteresis characteristics, respectively, and
Between the first incident light amount and the outgoing light amount from the electrode side active layer end face and between the second incident light amount and the outgoing light amount from the second electrode side active layer end face. A bistable semiconductor laser having hysteresis characteristics and thresholds of the third and fourth hysteresis characteristics controllable by the first and second injection currents respectively; A first current source that supplies an injection current to the first electrode, the injection current having a large threshold value of the third hysteresis characteristic with respect to a predetermined first incident light amount; A second injection current is supplied to the second electrode, which is in the second hysteresis loop and has a large threshold value of the fourth hysteresis characteristic with respect to a predetermined second incident light amount. From the current source That the optical memory (n is a positive integer) 2n wherein pieces, these optical memory Yes in light cascaded in contact with each other the end surfaces of the active layer of the semiconductor laser, 2i-1 (i =
The current value of the first current source of the 1,2 ... n) th optical memory is in the first hysteresis loop,
And a first electric signal for generating a pulse having a current value showing a small threshold value of the third hysteresis characteristic with respect to a predetermined first incident light quantity, and the 2i-th optical memory of the first electric signal. A current value in which the current value of the first current source is within the first hysteresis loop, and the threshold value of the third hysteresis characteristic is small with respect to a predetermined first incident light amount. An optical signal shift circuit is provided, which is provided with injection current control means for alternately generating the second electric signal for generating the pulse.

Further, according to the present invention, the first and second electrodes are arranged apart from each other in the resonance axis direction, and the first injection current and the emitted light amount supplied from the first electrode and the second electrode are provided. Has the first and second hysteresis characteristics between the second injected current and the emitted light amount, respectively, and has the first incident light amount and the emitted light from the end face of the active layer on the side of the first electrode. The third and fourth hysteresis characteristics between the second incident light quantity and the second incident light quantity from the end face of the active layer on the second electrode side. A bistable semiconductor laser whose threshold value is controllable by the first and second injection currents respectively; and a first bistable semiconductor laser in the first hysteresis loop, which is set for the predetermined first incident light quantity. The threshold value of the hysteresis characteristic of 3 is large A first current source that supplies an injection current to the first electrode, which is in the second hysteresis loop, and the fourth hysteresis characteristic with respect to a predetermined second incident light amount. A second injection electrode that supplies an injection current showing a large threshold value of
2n (n is a positive integer) optical memories each of which is composed of a current source, and these optical memories are connected in cascade with the end faces of the active layers of the semiconductor lasers contacting each other, and 2i-1 (i = 1, i = 1,
The current value of the first current source of the 2nd ... n) th optical memory is within the first hysteresis loop, and the third value is set for the first incident light amount determined in advance. A first electric signal for generating a pulse having a current value showing a small threshold value of the hysteresis characteristic and a current value of the first current source of the 2i-th optical memory are included in the first hysteresis loop. And an injection current for alternately generating a second electric signal for generating a pulse having a current value showing a small threshold value of the third hysteresis characteristic with respect to a predetermined first incident light amount. The current value of the control means and the second current source of the 2i-1 (i = 1,2 ... N) th optical memory is within the second hysteresis loop and is predetermined. With respect to the second incident light amount, A third electric signal for generating a pulse of a current value having a small threshold value of the hysteresis characteristic of, and a current value of the second current source of the 2i-th optical memory in the second hysteresis loop. Yes, and
For the second incident light amount determined in advance, the fourth
A second injection current control means for alternately generating a fourth electric signal for generating a pulse of a current value having a small threshold value of the hysteresis characteristic of 1. Is obtained.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 9 is a sectional view showing a specific example of a bistable semiconductor laser used in the present invention. The structure is almost the same as that of a commonly used current injection type semiconductor laser, for example, GaAlAs.
This is a double-heterojunction structure laser made of / GaAs or InGaAsP / InP. However, this is different from a normal semiconductor laser in that the electrode is divided into two parts, an electrode 901 and an electrode 902, sandwiching a groove in the resonance axis direction.

An example of such a bistable semiconductor laser is the Proceedings of the Annual Conference of the Institute of Electronics, Communication and Communications, Division of Light and Radio (1982) 27.
The one mentioned in number 2 is known.

The electrode 901 of the bistable semiconductor laser 900 shown in FIG.
The injection currents i ₁ and i ₂ are supplied to the 902, respectively, so that the values of either one of the two optical signals P ₁ and P ₂ incident on the one end 904 and the other end 905 of the active layer 903, respectively. And the optical signal P ₀ from both ends of the active layer 903.
Is emitted.

FIG. 10 is a diagram showing characteristics of the bistable semiconductor laser 900 shown in FIG. Figure 10 bistable semiconductor laser 900 shown in FIG. 9, as shown in (a) is the amount of incident light P ₁ = 0, the injection current i ₂ = injected current i ₁ and the exit light quantity P ₀ when the i _2b In between 1
It has a hysteresis characteristic indicated by 000, and the injection current i ₁
Two stable points A and B are shown by setting to _1b . FIG. 10 (b) is a diagram showing the relationship between the incident light quantity P ₁ and the emitted light quantity P ₀ when the injection current i ₂ = i _2b . The bistable semiconductor laser 900 shown in FIG. The characteristic shown by 1001 is obtained by setting the value of i _{1 to} the value of i _1b shown in FIG. Here, the value of the injection current i ₁ is shown in FIG. 10 (b).
When set to i _1w as shown in, the bistable laser diode 900 is 1002
The characteristics shown by are shown.

On the other hand, as shown in FIG. 10 (c), the bistable semiconductor laser 900 shown in FIG. 9 also has an incident light amount P ₂ = 0 and an injection current i ₁ = i _1b.
At this time, there is a hysteresis characteristic indicated by 1003 between the injection current i ₂ and the emitted light amount P _0, and two stable points A and B are shown by setting the value of the injection current i ₂ to i _2b . FIG. 10 (d) is a diagram showing the relationship between the incident light quantity P ₂ and the outgoing light quantity P ₀ when the injection current i ₁ = i _1b . The bistable semiconductor laser 900 shown in FIG. The characteristic shown by 1004 is obtained by setting the value of i _{2 to} the value of i _2b shown in FIG. 10 (c). Here, the value of the injection current i ₂ is i _2w shown in FIG. 10 (e).
When set to, the bistable semiconductor laser 900 exhibits the characteristics shown by 1003. Points A and B in FIG. 10A represent the same points as points A and B in FIGS. 10B to 10D, respectively.

FIG. 11 is a diagram showing the relationship between the injection current i ₂ and the voltage V of the electrode 902 when the incident light quantities P ₁ and P ₂ = 0 and the injection current i ₁ = i _1b . In the bistable semiconductor laser shown in FIG. 9, when the injection current i ₂ is increased from i _2c , the voltage V increases along the path of H → F → I, and conversely the injection current i ₂ is changed from a value of i _2t or more. When it is decreased, the voltage V exhibits a hysteresis such that it decreases in the path of I → G → H. Therefore, assuming that the injection current i ₂ = i _2b , the bistable semiconductor laser shown in FIG. 9 has the electrode voltage at the stable point A in FIGS. 10 (a), (b), (c), and (d). v ₀ is shown in FIGS. 10 (a), (b), (c), (d)
The electrode voltage V ₁ is shown at the stable point B of FIG.

Further, the bistable semiconductor laser 900 shown in FIG. 9 has no difference between the injection current i ₁ and the voltage of the electrode 901 when the incident light amounts P ₁ and P ₂ = 0 and the injection current i ₂ = i _2b. Have a similar relationship.

FIG. 1 is a diagram showing an embodiment of the first invention of the present application.

According to FIG. 1, in this embodiment, a bistable semiconductor laser 10 is used.
0 to 105 are arranged in cascade with the end faces of the active layers being in contact with each other, and the first electrodes 106 to 111 of the respective bistable semiconductor lasers are respectively connected by current sources 112 to 117 and the second electrodes 118 to 1 are connected.
An injection current is supplied to each of 23 by current sources 124 to 129.

Bistable semiconductor lasers 100 and 101, 102 and 103, shown in FIG.
104 and 105 respectively constitute an optical master-slave flip-flop circuit, which is added to one end of the active layer of the bistable semiconductor laser 100 in response to a set of clock electric signals φ ₂ and φ ₁ applied to the terminals 130 and 131. The optical signal 132 thus obtained is sequentially shifted to the bistable semiconductor lasers 100-101-102-103-104-105.

FIG. 2 shows the bistable semiconductor lasers 100 and 101 shown in FIG.
2 shows an optical master-slave flip-flop circuit configured by. In FIG. 2, the same reference numerals as those in FIG. 1 denote the same components as those in FIG.

FIG. 3 is a time chart for explaining the operation of the optical master slave flip-flop circuit shown in FIG.

According to FIG. 3, the optical signal D ₁ is applied to the input of the optical master-slave flip-flop circuit shown in FIG. 2, and the optical signal D ₁ is latched by controlling the variable current sources 112 and 113. Output as optical signal Q ₂ .

The electrode 106 of the bistable semiconductor laser 100 shown in FIG.
The injection currents T ₁ and T ₁ ′ having the electrode values i _1b are supplied to the variable current source 112 and the constant current source 124, respectively, and the electrodes 107 and 119 of the bistable semiconductor laser 101 are supplied to the variable current source 113. The injection currents T ₂ and T ₂ ′ are supplied by the constant current source 125 and the constant current source 125, respectively.

The bistable semiconductor lasers 100 and 101 shown in FIG.
As shown in FIG. 3, the variable current sources 112 and 113 respectively supply the injection current having the current value i _1b shown in FIG. 10 (a). Thus, the bistable semiconductor lasers 100 and 101 are supposed to store the optical information of X _n by holding either one of the stable points A or B shown in FIG. 10 (a).

Here, when the value of the injection current T ₁ is reduced to i _1c shown in FIG. 10 (a), the bistable semiconductor laser 100 becomes A, B in FIG. 10 (a).
The emitted light quantity Q ₂ becomes 0 at any stable point. On the other hand, in this bistable semiconductor laser 100, the input optical signal D ₁ having the optical information X _{n + 1 is applied} to one end 200 of the active layer and the other end 201 of the active layer.
An output optical signal Q ₂ of the bistable semiconductor laser 101 having optical information X _n is added to each of them. Injection current T ₁ and T ₁ ′
The values of i _1w and i _2b are shown in FIGS. 10 (a) and 10 (c), respectively.
By setting the light quantities of the optical signals D ₁ and Q ₂ to P _1b and P _2h shown in FIGS. 10 (c) and 10 (d), respectively, only the input optical signal D ₁ having the optical information X _{n + 1} is set. Can be latched.

Next, when the injection current T ₂ of the bistable semiconductor laser 101 is reduced to i _1c shown in FIG.
₂ becomes 0. Then, the injection currents T ₂ and T ₂ ′ are set to the first value.
0 Figure (a), is set to i _{1 w,} 1 _2b shown in (c). Then, since the optical information X _{n + 1} is at one end 202 of the active layer that are stored in the bistable semiconductor laser 100 of the bistable semiconductor laser 101 is added as an optical signal Q _1, the optical signal Q ₁ light amount P By selecting _0h as the light amount P _1h shown in FIG. 10 (b), the optical information X
_{n + 1} is stored in the bistable semiconductor laser 101 and is stored at one end 20 of the active layer.
2 and 203 output as an optical signal Q ₂ . Such optical master-slave flip-flop circuit in FIG. 2 in the latches optical information X _{n + 1} applied to the input by controlling the injection current T ₁ to the bistable semiconductor laser 100, the injection current T ₂ Bistable semiconductor laser 100 by controlling
The optical information X _{n + 1} stored in the memory is transferred to the bistable semiconductor laser 101.

That is, the embodiment of the first invention of the present application shown in FIG. 1 is stored in the bistable semiconductor lasers 101, 103 by controlling the current sources 113, 115 and 117 according to the clock electric signal φ ₂ applied to the terminal 130. Existing optical information is transferred to the bistable semiconductor lasers 102 and 104, respectively, and the input optical signal 132 is stored in the bistable semiconductor laser 100, and the current sources 112 and 11 are responsive to the clock electric signal φ ₁ applied to the terminal 131.
Bistable semiconductor laser 100,1 by controlling 4,116
The optical information stored in 02,104 is used for bistable semiconductor lasers 101,10.
Latch at 3,105. Further, by repeating the same operation, the optical signal 132 applied to the input can be sequentially shifted toward the output.

FIG. 4 is a diagram showing an embodiment of the second invention of the present application.
In this figure, the same reference numerals as those in FIG. 1 denote the same components as in FIG.

Bistable semiconductor lasers 100 and 101, 102 and 103, shown in FIG.
104 and 105 respectively constitute an optical master-slave flip-flop circuit.

FIG. 5 shows an optical master-slave flip-flop circuit composed of the bistable semiconductor lasers 100 and 101 shown in FIG. In FIG. 5, the same reference numerals as those in FIG. 4 denote the same components as those in FIG.

FIG. 6 is a time chart for explaining the operation of the optical master slave flip-flop circuit shown in FIG.

According to FIG. 6, in the optical master-slave flip-flop circuit shown in FIG. 5, the injection currents T ₁ and T ₂ are controlled similarly to the optical master-slave flip-flop circuit shown in FIG. The input optical signal X _{n + 1} applied to one end 200 of the active layer of the laser 100 is latched in the bistable semiconductor laser 100, and the optical information X _{n + 1} latched in the bistable semiconductor laser 100 is transferred to the bistable semiconductor laser 101. Can be memorized.

The optical master-slave flip-flop circuit shown in FIG. 5 further sets the injection currents T ₁ and T ₂ to the constant value i _1b shown in FIG. 10 (b) as shown in FIG. Source 1
By controlling the injection currents T ₂ ′ and T ₁ ′ by 24 and 125, the input optical signal X ′ _{n + 1} applied to one end 500 of the active layer of the bistable semiconductor laser 101 is transferred to the bistable semiconductor laser 101.
The optical information X ′ _{n + 1} latched in the bistable semiconductor laser 101 can be stored in the bistable semiconductor laser 100.

That is, in the embodiment of the second invention of the present application shown in FIG. 4, the clock electrical signal φ ₂ , applied to the terminals 130 and 131,
The input optical signal 132 is shifted to the right according to φ ₁ , and the terminals 133, 1
The input optical signal 135 can be shifted to the left in response to clock electrical signals φ ₂ ′ and φ ₁ ′ applied to 34.

FIG. 7 is a diagram showing an example of an optical signal shift circuit related to the present invention. In this figure, the same reference numerals as those in FIG. 1 denote the same components as in FIG.

The bistable semiconductor laser 101, as described in FIG. 11,
The light quantities P ₁ and P _{2 of the} optical signals applied to both ends of the active layer are 0, and the injection currents applied to the electrodes 107 and 119 are i _1b and i _2b , respectively.
If so, the voltage v ₀ or v ₁ appears at the electrode 119 depending on which of the two stable points A and B shown in FIG. 10 the bistable semiconductor laser 101 is at.

In the optical signal shift circuit shown in FIG.
Current sources 112, 114, 116 depending on the electrical signal φ ₁ applied to
By controlling the bistable laser diode 100, 102,
Move all 104 to stable point A shown in FIG. As a result, the light quantity of the optical signal applied by the bistable semiconductor lasers 100, 102 to the end faces 202, 203 of the active layer of the bistable semiconductor laser 101 becomes zero, and therefore the electrode 119 is responsive to the optical information stored in the bistable semiconductor laser 101. As a result, either _one of the voltages V ₀ and V ₁ is obtained. The comparator 700 uses this voltage as the reference voltage V
_By comparing it with _th , the optical information stored in the bistable semiconductor laser 101 is output to the terminal 703 as an electric signal.

In this way, in the optical signal shift circuit shown in FIG. 7, bistable semiconductor lasers 101 and 10 are provided as optical signals, respectively.
The optical information input in series to the 3,105 is compared with the comparators 700,701,702.
Can be output in parallel to the terminals 703, 704, 705 as an electric signal.

FIG. 8 is a diagram showing another example of the optical signal shift circuit related to the present application. In FIG. 8, the same reference numerals as those in FIG. 1 denote the same components as those in the first embodiment.

In the optical signal shift circuit shown in FIG. 8, the bistable semiconductor lasers 100, 102, 10 are controlled by controlling the current sources 112, 114, 116 according to the electric signal φ ₁ applied to the terminal 131.
Move all 4 to stable point A shown in FIG. As a result, the bistable semiconductor laser 101 is made
Since the light amount of the optical signal applied to the end face 203 of the active layer becomes ₀ , the relationship between the injection current i ₂ of the electrode 119 and the emitted light amount P ₀ of the end face 203 corresponds to the characteristic shown in FIG. 10 (c). To do. Here, once the injection current i ₂ of i _2t or more is added by controlling the current source 125 according to the electric signal input to the terminal 800, the bistable semiconductor laser 101 moves to the stable point B and the injection current i ₂ Is lowered to i _2c , it moves to stable point A.

That is, in the optical signal shift circuit shown in FIG. 8, optical signals corresponding to the electric signals applied to the terminals 800, 801, 802 can be input in parallel to the bistable semiconductor lasers 101, 103, 105, respectively.

(Effects of the Invention) As described above, according to the invention of the present application, an optical signal shift circuit capable of shifting a data optical signal to the left or right according to a clock electrical signal can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the first invention of the present application, FIG. 2 is a diagram showing an optical master slave flip-flop circuit constituted by the bistable semiconductor lasers 100 and 101 shown in FIG. 1, and FIG. Is a time chart for explaining the operation of the optical master-slave flip-flop circuit shown in FIG.
FIG. 4 is a diagram showing an embodiment of the second invention of the present application, FIG. 5 is a diagram showing an optical master slave flip-flop circuit constituted by the bistable semiconductor lasers 100 and 101 shown in FIG. 4, and FIG. Is a time chart for explaining the operation of the optical master-slave flip-flop circuit shown in FIG. 5, FIG. 7 is a diagram showing an example of an optical signal shift circuit relevant to the present invention, and FIG. 8 is relevant to the present invention. Showing another example of the optical signal shift circuit for performing the above, FIG. 9 is a sectional view showing a specific example of the bistable semiconductor laser used in the present invention, and FIG.
(D) and FIG. 11 are diagrams showing the characteristics of the bistable semiconductor laser shown in FIG. In the figure, 100, 101, 102, 103, 104, 105 and 900 are bistable semiconductor lasers, 112, 113, 114, 115, 116, 117, 124, 125, 126,
127, 128 and 129 represent current sources, and 700, 701 and 702 represent comparators, respectively.

Claims (2)

[Claims] 1. A first electrode and a second electrode are arranged apart from each other in a resonance axis direction, and are provided between a first injection current and an emitted light amount supplied from the first electrode and from the second electrode. The first and second hysteresis characteristics between the second injected current and the emitted light amount, and the first incident light amount and the emitted light amount from the end face of the active layer on the side of the first electrode. Between the second incident light quantity and the second incident light quantity from the end face of the active layer on the second electrode side, and third and fourth hysteresis characteristics, respectively, of the third and fourth hysteresis characteristics. A bistable semiconductor laser whose threshold value is controllable by the first and second injection currents respectively; and a first bistable semiconductor laser in the first hysteresis loop, which is set for the predetermined first incident light quantity. The threshold value of the hysteresis characteristic of 3 is large A first current source that supplies an injection current indicating a value to the first electrode, and a fourth hysteresis characteristic that is in the second hysteresis loop and that corresponds to a predetermined second incident light amount. A second injection electrode that supplies an injection current showing a large threshold value of
2n (n is a positive integer) optical memories each of which is composed of a current source, and these optical memories are connected in cascade with the end faces of the active layers of the semiconductor lasers contacting each other, and 2i-1 (i = 1, i = 1, The current value of the first current source of the 2nd ... n) th optical memory is within the first hysteresis loop, and the third value is set for the first incident light amount determined in advance. A first electric signal for generating a pulse having a current value showing a small threshold value of the hysteresis characteristic and a current value of the first current source of the 2i-th optical memory are included in the first hysteresis loop. And an injection current for alternately generating a second electric signal for generating a pulse having a current value showing a small threshold value of the third hysteresis characteristic with respect to a predetermined first incident light amount. That the control means are equipped Optical signal shifting circuit to symptoms. 2. A first electrode and a second electrode are arranged apart from each other in a resonance axis direction and are provided between a first injection current and an emitted light amount supplied from the first electrode and supplied from the second electrode. The first and second hysteresis characteristics between the second injected current and the emitted light amount, and the first incident light amount and the emitted light amount from the end face of the active layer on the side of the first electrode. The third and fourth hysteresis characteristics between the second incident light amount and the second incident light amount from the end face of the active layer on the second electrode side. A bistable semiconductor laser whose threshold values are controllable by the first and second injection currents respectively; and a third bistable semiconductor laser which is in the first hysteresis loop and which has a predetermined first incident light amount. Shows a large threshold value A first current source that supplies an injection current to the first electrode and a threshold value of the fourth hysteresis characteristic that is in the second hysteresis loop and that is predetermined for a second incident light amount. 2n (n is a positive integer) optical memories including a second current source for supplying an injection current having a large value to the second electrode, and these optical memories include an end face of the active layer of the semiconductor laser. Are connected to each other in cascade, and the current value of the first current source of the 2i-1 (i = 1,2 ... N) th optical memory is in the first hysteresis loop. And a first electric signal for generating a pulse having a current value showing a small threshold value of the third hysteresis characteristic with respect to a predetermined first incident light amount, and a 2i-th optical memory The current value of the first current source is A second electric signal which is in a hysteresis loop of No. 1 and which generates a pulse of a current value showing a small threshold value of the third hysteresis characteristic with respect to a predetermined first incident light amount; And the injection current control means for alternately generating the current value of the second current source of the 2i-1 (i = 1,2 ...
A third electric signal which is in a hysteresis loop and which generates a pulse of a current value showing a small threshold value of the fourth hysteresis characteristic with respect to a predetermined second incident light amount, A current value of the second current source of the 2i-th optical memory is within the second hysteresis loop, and a threshold value of the fourth hysteresis characteristic with respect to a predetermined second incident light amount. Is provided with a second injection current control means for alternately generating a fourth electric signal for generating a pulse of a current value exhibiting a small value.