JPH02245722A - Optical shutter array device - Google Patents

Abstract

PURPOSE:To make a shutter operation to a data signal at a high speed and by a light signal by combining plural pieces of optical bistable elements. CONSTITUTION:The light signal for a control signal is inputted to a groove 107 of a 1st bistable semiconductor laser 10 and the light signal for another control signal is inputted to a groove 107 of a 2nd bistable semiconductor laser 11. The lasers 10, 11 oscillate if the inputted control signals are above the threshold. A semiconductor optical shutter 13 has the characteristics similar to the characteristics of the lasers 10, 11 and acts to attain the oscillation state only when both the lasers 10, 11 attain the oscillation sate. The data signal light is inputted from the groove 139 of the semiconductor optical shutter 13, is guided in an active layer 133, is reflected by the 45 deg. angle face of the groove 140, and is emitted from a window 141. The active layer 133 has a large absorption and the signal light is not emitted unless the semiconductor optical shutter 13 is in the oscillation state. The control of the shutter operation by the light control signals is enabled in this way and the switch time of several nanoseconds is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical shutter array device that controls the operating state of a semiconductor laser using external light and performs an optical shutter operation.

[Conventional technology]

Conventionally, an optical shutter array device uses a multilayer polarization splitting element as a polarizer and an analyzer, and a PLZT (strong It had a structure in which a polarization rotator (made of dielectric transparent ceramic) was inserted. The PLZT
The polarization rotator is divided into 16 4×4 parts, each part has an electrode, and the polarization plane of input light can be rotated by 90'' by applying a voltage.

Further, the polarization planes of the polarizer and analyzer are shifted by 90°.

With the above configuration, the input light input from the polarization plane side passes through the polarizer and the polarization plane is aligned in one direction, and when no voltage is applied to the PLZT polarization rotator, the polarization plane does not change and the polarization plane is aligned in one direction. The light passes through the PLZT polarization rotator and reaches the analyzer, but since the polarization planes of the light and the analyzer are shifted by 90 degrees, the light does not pass through the analyzer at all. On the other hand, when a voltage is applied to the PLZT polarization rotator, the polarization plane of the light is rotated by 90 degrees and can pass through the analyzer. Therefore, in the above configuration example, the shutter can be opened and closed depending on the voltage application state of the PLZT polarization rotator.

In this conventional example, the voltage is 500V when on and -50V when off.
By applying a voltage of 30 dB or more, characteristics of an extinction ratio of 30 dB or more and a switching time of 5 μs were obtained.

[Problem that the invention seeks to solve] However,
In the above conventional example, the PLZT polarization rotator has, for example, 500 cm.
Because it operates by applying a moderately high voltage and rotating the polarization plane of the light to adjust the amount of transmitted light, it has the following drawbacks.

(1) Even when a high voltage is applied to the ferroelectric transparent ceramic PLZT, it takes a considerable amount of time until the polarization angle is stably determined, and the switching time is long.

(2) Since the opening and closing of the shutter is controlled electrically, electrical signals are transmitted separately to each shutter in the shutter array.
A control electrode is required for each shutter, and when the number of shutter arrays increases, the electrode arrangement becomes complicated.

[Means for Solving the Problems] According to the present invention, by using the characteristics of an optical bistable element and an integrated element that combines optical bistable elements, it is possible to control the shutter operation with an optical control signal, and the semiconductor Based on this basic idea, a switch time of several nanoseconds was obtained.

[Operation] Characteristics of an optical bistable element can be changed at high speed (
G) Iz level) control.

[Example] Figure 1 is a diagram that best represents the features of the present invention. In the figure, 1 is a semiconductor shutter array, 2 is a branching device, and 3
is a combiner, 4.41.71.7 is an optical fiber for data signals, 5.51.6.61 is an optical fiber for control signals,
Reference numeral 8 denotes a lens attached to the tip of each optical fiber in order to focus the light emitted from the optical fiber onto the semiconductor shutter array l or to collect the light input from the semiconductor shutter array 1 to the optical fiber, and 9 is the semiconductor shutter array. 1 in l
two semiconductor optical shutters (optical shutter elements).

Here, the semiconductor optical shutter 9 is shown in FIGS. 2 and 3.

The structure is shown in FIGS. 4 and 5.

FIG. 2 specifically shows the semiconductor optical shutter 9. As shown in FIG. , 10.11 is a 1.2 bistable semiconductor laser for decoding control signals, 12 is an optical waveguide having a merging function, and 13 is a semiconductor optical shutter. Broken lines AI and A in Figure 2
FIG. 3 is a block diagram taken at point 2.

In FIG. 3, +01 is, for example, n-type Alo3Gao,
? A semiconductor substrate made of AS and approximately 100 μm thick, 102
103 is an active layer of about 0.1 μm thick and made of, for example, GaAs, and 104 is a p-type A, for example.
The second layer is made of I0.3 Gao and 7 As and has a thickness of approximately 2 μm.
A crat layer 105 is a cap layer made of, for example, p-type GaAs, +06 is a second electrode made of, for example, an alloy of gold and zinc formed on a part of the cap layer 105, and 107 is at an angle of 45° with respect to the substrate 101. A first groove with a 90° plane, 108 a second groove with four planes perpendicular to the substrate 101, and 109 a 5iOz, Ti substrate with a reflectance of 50%, for example.
The first reflecting mirror is a dielectric multilayer Bragg reflecting mirror made of O□, the saturable absorption region 110 into which electrons and holes are not injected, and the first electrode 111 made of, for example, an alloy of gold and germanium. First and second bistable semiconductor lasers 10
．． 11 is different in the size of the second electrode 106 of each bistable semiconductor laser 10, 11, and the saturable absorption region 110 is different.
are different in size. With this configuration, the optical input/output characteristics of the bistable semiconductor lasers 10 and 11 have different optical thresholds as shown by lines A and B shown in FIG.

FIG. 4 is a configuration diagram of the semiconductor optical shutter 13 taken along the broken line A3 in FIG.

In FIG. 4, 101 is, for example, n-type Alo, 3Gao
, a semiconductor substrate made of tAa and approximately 100 μm thick, 1
32 is a first cladding layer made of, for example, n-type Alo, 5Gao, or 7AS and has a thickness of about 3 μm; 133 is made of, for example, Ga.
The active layer is made of As and has a thickness of about 0.1 μm; [34 is, for example, p-type Alo or sGa. ,, made of As and about 2μ thick
+35 is a cap layer made of, for example, p-type GaAs; 136 is a second electrode made of, for example, an alloy of gold and zinc formed on a part of the cap layer 135; 1;
Reference numerals 37 and 138 indicate first and second grooves formed of four planes perpendicular to the substrate 101, and 111 indicates a first electrode made of, for example, an alloy of gold and germanium. Also, 150 is an electron.

This is a saturable absorption region where holes are not injected.

In addition, 12 in FIG. 4 is an optical waveguide, for example, Alo, 5G
A first layer 121 made of Alo, sAs and about 3 μm thick; a waveguide layer 122 made of Alo, 5Gao, and 7AS and about 0.1 μm thick;
The second cladding station is made of , 5 Gao, and sAs and has a thickness of about 2 μm! Consists of 23.

FIG. 5 is a configuration diagram of the semiconductor optical shutter 13 taken along the broken line B1 in FIG.

In FIG. 5, parts with the same numbers as in FIG. 4 represent the same parts as in FIG. 4. 139 and 140 are the first planes formed by two planes having angles of 90° and 45° with respect to the substrate 101. The second groove 141 is a window provided in the first electrode, and the second groove 141 is a window provided in the first electrode.
It is formed in a portion corresponding to the groove 140.

Using the configuration described above, the operation of the present invention will be described with reference to FIG. Here, as an example to explain the operation shown in FIG. 1, a case will be described in which communication (data exchange) is performed between processors in a three-processor system. Each processor generates a data signal to communicate and a signal (control signal) indicating the party to communicate with, converts this signal into an optical signal, and inputs the data signal to optical fiber 4 and the control signal to optical fibers 5 and 6. do. The data signal and control signal output from each processor are branched into three by the splitter 2, and inputted through the optical fibers 41, 51, and 61 to the three optical shutters 9 arranged horizontally in the optical shutter array l by the rod lens 8. Ru.

In each optical shutter 9, a control signal is inputted to each first groove 107 of an optical bistable semiconductor laser 10.11.
The optical signal from the optical fiber 51 for control signals is input into the first groove 107 of the second bistable semiconductor laser 11, and the optical signal from the optical fiber 6! Input the optical signal from. If the control signal input to each bistable semiconductor laser 10.11 is equal to or greater than the optical threshold of each bistable semiconductor laser 10.11, each bistable semiconductor laser 10.11 shifts to a laser oscillation state. Therefore, it is possible to create several different intensities of the light input to the semiconductor optical shutter 13 of the optical waveguide 12 depending on how the control signal light is applied. The semiconductor optical shutter 13 is the first. Second bistable semiconductor laser 10.11
It has similar characteristics, and an arbitrary light threshold can be set.

For example, each semiconductor optical shutter 9 of the optical shutter array 1 is numbered as shown in FIG. Second bistable semiconductor laser 10. , ll light threshold Pthllll.

Pth2 Eyes will be displayed 0 In this example, 1
For example, if the data and control signals from two processors are
11), (12), and (13). Here (11), (12), (13)
Each of the first . The optical threshold of the second bistable semiconductor laser is set as Pthll<Pthll□<Pth++5th Ptha>Pth2+i>Pthz+3. Also,
The semiconductor optical shutter 13 is the first one of each optical shutter 9. The oscillation state is set only when the second bistable semiconductor lasers 10 and 11 are both in the oscillation state. For example, (12)
In order to bring only the semiconductor optical shutter 13 of the semiconductor optical shutter 9 into the oscillation state, the power (P,) of the control signal light input to the first bistable semiconductor laser lO is set such that Pt1ll+2≦
P+<Pth++s, and the second bistable semiconductor laser 11
The power (P2) of the control signal light input to Pth212
By setting ≦Pi<Pthz++, the first degree second bistable semiconductor laser 1 in the semiconductor optical shutter 9 in (12)
Only the semiconductor optical shutters 13 of the semiconductor optical shutters 9 of (12) are in the oscillating state.

In addition, by inputting a control signal for the power of P1≧Pth++s+ h≧P211, (11), (12)
, (13) The semiconductor optical shutter 13 of the semiconductor optical shutter 9 enters the oscillation state.

On the other hand, the semiconductor optical shutter 13 receives the data signal light from its first groove 139 by reflection from a 45° angle surface.
The light is guided through the active layer 133, is reflected by the 45° angle surface of the second groove 140, and is emitted through the window 141 in the first electrode 111. Here, if the semiconductor optical shutter 13 is not in the oscillation state, the active layer 133 has a large absorption and the signal light is absorbed during the waveguide, and the signal light is not emitted from the window 141. To turn off the semiconductor optical shutter 9 in the state, the semiconductor shutter array 1
This is done by reducing all bias current flowing to zero.

As described above, the signal light transmitted through the optical shutter array 1 is inputted using the optical fibers 71 and the Herrod lens 8, which are installed perpendicularly on the input side as a set of three, and
The optical fibers are combined into one optical fiber 7 and connected to each processor.

In addition, current injection electrodes (11), (21), (
31) and (+2) , (22) , (32) and (1
By classifying into three categories (3), (23), and (33), when communication between any two processors ends, the bias applied to the electrode containing the optical shutter 9 used for the communication By reducing the current to zero, it is also possible to communicate with other processors.

bloodbath l FIG. 8 shows another embodiment of the invention.

FIG. 8 shows that the semiconductor optical shutter 13 in the semiconductor optical shutter 9 of the first embodiment is realized by a surface-emitting semiconductor bistable laser.

In FIG. 8, 201 is, for example, n-type Ala, 3Ga
o, a semiconductor substrate made of 7As and approximately 100 μm thick;
202 is high resistance Alo, 5Gao, sAs, for example.
The embedded stone 203 is, for example, n-type Alo, 3
Gao? The first cladding layer 204 made of AS and having a thickness of about 3 μm is made of, for example, p-type GaAs and has a thickness of about 3 μm.
, the active layer 205 with a diameter of about IO μmφ is made of, for example, p-type Al.
The second layer is made of O, 3Gao, and 7AS and has a thickness of approximately 1 μm.
The cladding layer 206 is made of, for example, p-type GaAs and has a thickness of about 1 μm, and the saturable absorption layer 210 is made of, for example, p-type Ala,
The cap layer is made of IGao, 9AS and has a thickness of about 1 μm, and only a portion corresponding to the region of the active layer 204 is formed on the saturable absorber 920G.

Reference numeral 207 denotes an insulating film made of, for example, λ, Sio, and the insulating film 207 formed on the cap layer 210 has a ring-shaped portion without an insulating film. 211 is a second electrode made of, for example, an alloy of gold and zinc, and the cap layer 210 and the ring-shaped insulating film 2
They touch at the part without 08. 215 is a communicating hole that communicates from one main surface to the other main surface of the substrate 201 and has a diameter of about 200 μmφ; 212 is a first hole made of, for example, an alloy of gold and germanium;
The electrode 213 is made of, for example, a vapor-deposited gold film with a reflectance of 90%.
The first reflecting mirror 214 is a first groove formed of a plane perpendicular to the substrate 201. 12 is an optical waveguide similar to the first embodiment.

The semiconductor optical shutter 13 configured as described above provides the optical input/output characteristics shown in FIG. 7. Therefore, the first . Only when both of the second bistable semiconductor lasers enter the oscillation state and the oscillated light is guided through the optical waveguide 12 and enters the saturable absorber N206, the amount of light exceeds the optical threshold of the semiconductor optical shutter 13. The light threshold must be adjusted so that Using the surface-emitting semiconductor bistable laser adjusted in this way, it is possible to input the input data signal light from the upper side (second electrode 211) side in FIG. 6 and take it out from the first reflecting mirror 213 side. It becomes possible. Of course, even if the input/output direction is reversed, the same operation will occur. The detailed operation is the same as in the first embodiment.

A third embodiment of the present invention is shown in Figures 10 and 11. FIG. 11 corresponds to one semiconductor optical shutter 9 in the optical shutter array 1 in FIG. FIG. 10 is a cross-sectional configuration diagram taken along broken line A5 in FIG. 11.

In FIG. 10, 301 is, for example, Alo, 4Gao
, 302 is a semiconductor substrate made of aAs, for example, GaA.
The saturable absorbing layers 303 and 305 are made of A1, for example.
0.5 Gao, ? A Bragg reflector consisting of 40 pairs of alternating AS and AlAs, for example, with a center wavelength of 880 nm.
first and second reflectors with a reflectance of about 90% at 30
4 is, for example, a first medium layer made of GaAs with a thickness of 2.5 μm; 306.308 is, for example, Alo, 5Gao,
Third and fourth Bragg reflectors each having 40 pairs of alternating layers of As and AlAs, the layer thickness of which is adjusted to have a reflectance of about 90% at a center wavelength of 850 nm, for example;
307 is, for example, Alo, asGao with a thickness of 2.5 μm.
, 9? A second medium layer made of AS, 309 is the substrate 301
The first groove, 310, is composed of a 45° plane and a vertical plane.
This is a second groove having the same configuration as No. 09.

In this embodiment, the first and second reflecting mirrors 303 and 305, the first medium 304, and the third and fourth reflecting mirrors 306°3
08 and the second medium 307, each of which forms an optical bistable element, and will be referred to as a first and a second optical bistable element, respectively. The first and second optically bistable elements exhibit optical bistability for light with wavelengths of 880 nm and 850 nm, respectively.

In this embodiment, the wavelengths of the two control lights (lights coming to the optical shutter array 1 through the optical fibers 5 and 6 in FIG. 1) are set to 850 nm and 880 nm.

In addition, the entire optical shutter array has wavelengths of 850 nm and 88 nm.
By irradiating with 0 nm excitation light and excitation with a power below the optical threshold, the first and second optical bistable elements transitioned to the on state by the control light. The excitation light that is irradiated from the outside reaches the saturable absorption layer 302, and absorption of the excitation light saturates the absorption of the saturable absorption layer 302, making it transparent. In this state, the signal light incident from the first groove 309 can pass through the saturable absorption layer 302 without being absorbed.
The light is reflected by the second groove, passes through the substrate 301, and is emitted.

The shutter is closed by stopping the excitation light irradiation, and the operation of the optical shutter array is the same as in the first embodiment.

〔Effect of the invention〕

As explained above, by combining multiple optical bistable elements, an arbitrary optical shutter can be opened and closed at high speed of several tens of nanoseconds using control signal light, and shutter operation in response to data signals can be performed at high speed and optical There is an effect that can be done with.

Furthermore, there is no need to form electrodes on each semiconductor optical shutter 9 individually, and there is an effect of avoiding complexity in electrode arrangement that would be caused by an increase in the number of shutter arrays.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention, and FIG. 2 is a perspective view of a first embodiment of the present invention.
FIG. 3 is a perspective view of the semiconductor optical shutter element constituting FIG. 1, and FIG. 3 is a perspective view of the semiconductor optical shutter element constituting FIG. FIGS. 4 and 5 are cross-sectional views of the structure of the second bistable semiconductor laser, respectively. FIG. 6 is a cross-sectional view of the semiconductor optical shutter element in FIG. 7 is a schematic plan view of the shutter array, FIG. 8 is a sectional view of the second embodiment of the present invention, and FIG. 9 is the semiconductor optical shutter of FIG. 8. 10 and 11 are a cross-sectional view and a perspective view of a third embodiment of the present invention, respectively. 1... Optical shutter array, 9...
...One semiconductor optical shutter in the optical shutter array, 10, 11...The first and second bistable semiconductor lasers in the semiconductor optical shutter 9, 12......Having a merging function Optical waveguide, 13
......It is a semiconductor optical shutter element.

Claims (1)

[Claims] 1) An optical shutter array device formed by integrating a plurality of optical shutter elements, wherein the optical shutter elements have low light transmittance when the light intensity of input light exceeds a predetermined value. An optical switch element that transitions from a first stable state to a second stable state with high light transmittance, and the passage or non-passage of optical data is determined by this state change; and controlling the state change of the optical switch element. a plurality of optical bistable elements whose internal state changes according to the intensity of the optical control signal and whose optical output changes accordingly; the plurality of optical bistable elements and the optical switch; 1. An optical shutter array element, characterized in that it has an optical path that connects the element. 2) The optical shutter array device according to claim 1, wherein a semiconductor laser having a non-excitation region is used as the optical switch element and the optical bistable element. 3) The optical shutter array device according to claim 1, wherein a surface emitting type optical threshold element is used as the optical switch element, and a semiconductor laser having a non-excitation region is used as the optical bistable element. 4) The optical shutter array device according to claim 1, wherein a saturable absorber is used as the optical switch element, and a semiconductor Fabry-Perot etalon is used as the optical bistable element.