JPH02232615A - Light wavelength selector - Google Patents

Abstract

PURPOSE:To reduce the size and power consumption of the light wavelength selector by arranging a movable plate and a plane plate adjacently almost in parallel, using an insulator layer as a base, and providing a light deflection part where one end of the movable plate is supported on the plane plate and a diffraction grating where the projection light of the light deflection part is made incident. CONSTITUTION:When a voltage is applied between the movable plate 10 and plane plate 11, an electrostatic force operates between them and the movable plate 10 is displaced. By this displacement, the movable plate 10 reflects wavelength multiplex light in a different direction from that when no voltage is applied. Then a light signal having different single wavelength according to the displacement of the movable plate 10 is made incident on an output port part 9. For the purpose, a power source 13 controls the applied voltage to vary the quantity of displacement of the movable plate 10 and thus the incidence/projection conditions of the diffraction grating 8 are changed to control the wavelength of the light signal which is made incident on the output port part 9. Consequently, the size is reducible and the power consumption is made low.

Description

[Detailed Description of the Invention] <Industrial Application> The present invention provides a method for decoupling a desired channel (
The present invention relates to an optical wavelength selector for extracting optical signals of wavelengths), and is designed to be smaller and consume less power.

2. Description of the Related Art As an optical communication system, there is a wavelength division multiplexing system (WDM) that multiplexes and transmits a large number of optical signals having different wavelengths.

In the wavelength division multiplexing optical communication system, an optical wavelength selector is required at the terminal to extract an optical signal of a desired channel from a wavelength multiplexed optical signal.

It is desirable for an optical wavelength selector to be small and to have low power consumption.

Conventional optical wavelength selectors include (a) a method using a wavelength filter, (b) an ultrasonic scratch direction @ (AO
There is a method in which (D) is combined with a diffraction grating, and (C) a method in which the diffraction grating is rotated by a step motor.

(a) Method using a wavelength filter: In this type of optical wavelength selector, a multiple number of wavelength filters that allow only optical signals of individual wavelengths to pass are prepared, and by selecting a wavelength filter, light of a desired wavelength can be detected. Extract only the signal.

However, increasing the number of wavelengths multiplexed requires a correspondingly large number of wavelength filters, resulting in an increase in the size of the optical wavelength selector, which has the disadvantage that it cannot be miniaturized. Furthermore, when the number of wavelengths multiplexed is increased, a large number of wavelength filters are also required, which has the disadvantage of increasing the cost of the optical wavelength selector.

(bl A method of combining ultrasonic scratch folds and a diffraction grating: An example of the structure of this type of optical wavelength selector is shown in Figure 3. In the figure, 1-1 to 1 to N are lasers with different wavelengths, respectively. λ1 to λ8 from each laser diode.
The optical signals are multiplexed by the IXN coupler 2 and input into one end of the optical fiber 3. The other end of the optical fiber 3 is fixed to the input port section 4 of the optical wavelength selector 14. The optical wavelength selector 14 includes an input port section 4, a lens 5-1# ultrasonic damage direction (AOD) 6, and its driving section? , @ folded lattice 8,
There is a lens 5-2, an output boat section 9, and an output boat section 9.
An optical fiber or a photoelectric conversion element such as a photodiode is fixed to.

The wavelength-multiplexed light from the optical fiber 3 passes through the input port 4 and the lens 5-1 and enters the ultrasonic deflector 6.
The wavelength-multiplexed light emitted from #6 enters the diffraction grating 8. In the diffraction grating 8, the direction of light emission differs depending on the wavelength, so
A single wavelength optical signal passes through the lens 5-2 and is output to the output boat section 9.
incident on .

The third control of the wavelength of incidence on the output boat section 9 is ultrasonic deflection! ! This is done by changing the frequency of the applied voltage #6 to change the directing angle of the wavelength-multiplexed light from the ultrasonic deflector 6, that is, the conditions of incidence and output on the diffraction grating 8. By controlling the frequency of the voltage applied to the ultrasonic layer deflector 6 in this manner, it is possible to extract an optical signal of a desired channel.

However, because the extinction gt power of ultrasonic deflection l#6 is large,
The drawback is that it is difficult to reduce the power consumption of the optical wavelength selector.

(C) A method in which the diffraction grating is rotated by a step motor: In this type of optical wavelength selector, the ultrasonic deflection @S shown in Fig. 3 is
Instead, by rotating the diffraction grating itself using a step motor, the direction of incidence is changed, and an optical signal of a desired channel is extracted.

However, since a step motor is used to control the incident direction of the diffraction grating with high precision, the step motor and the drive mechanism are large in size, making it difficult to downsize.

Problems to be Solved by the Invention In view of the above-mentioned conventional technology, an object of the present invention is to provide an optical wavelength selector that can be downsized and reduce power consumption.

Means for Solving the Problems> An optical wavelength selector according to the present invention includes an optical deflection section and a diffraction grating into which light emitted from the optical deflection section is incident, and the optical deflection section comprises:
A movable plate that partially includes a conductive material that has a surface that reflects incident light and is supported by an insulator or semiconductor at both ends or one end, and a flat plate that partially includes a conductive material are approximately parallel to each other. It is adjacent to.

Effect> When voltage is applied between the conductive material of the movable plate and the flat plate, an electrostatic force acts between the movable plate and the flat plate, causing the movable plate to displace. This displacement changes the exit direction of the light reflected by the movable plate, changes the incident and exit conditions at the diffraction grating, and changes the direction of the light exiting from the diffraction grating.

The amount of displacement of the movable plate increases as it moves away from the support point, and increases as the applied voltage increases.

Therefore, by appropriately determining the input position of light to the surface of the movable plate in advance and controlling the applied voltage, it is possible to emit a desired single-wavelength optical signal from the diffraction grating toward a specific position. Operates as a wavelength selector.

In this case, the optical deflection section operates using electrostatic force and is not driven by current, so that the optical deflection section can be driven with low power.

Furthermore, since the light deflection section is composed of a flat plate, a movable plate, and its support, the structure is simple and can be manufactured in a small size.

Example 1 The present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which a base (not shown) of an optical wavelength selector includes an input port 4, a lens 5-1,
Diffraction grating 8, lens 5-2, output boat part 9, movable plate 1
0, a flat plate 11, a movable plate support 12-1,
A DC voltage is applied between the conductive portions of the movable plate 10 and the flat plate 11 by a variable voltage g4 source 13.

The input port section 4 fixes an optical fiber that transmits wavelength-multiplexed light, and inputs the wavelength-multiplexed light onto the surface of the movable plate 10 through a lens 5-1. The output port section 9 is an optical fiber or a photoelectric conversion element (for example, a photodiode)
are fixed, and the wavelength is separated by a diffraction grating 8, and a lens 5-2
This is where the optical signal that has passed through is input.

The light deflection unit has a movable plate 10 and a flat plate 11 adjacent to each other in substantially parallel,
One end of the movable plate 10 is supported by the flat plate 11 using the insulating layer as a support 12-1.

The surface of the movable plate 10 (at least the part on which the wavelength-multiplexed light is incident) has a function of reflecting the incident light. Also, when a voltage is applied between the movable plate 10 and the flat plate 11, both 10.11 At least a portion of both the movable plate 10 and the flat plate 11 is made conductive so that an electrostatic force acts between them.For example, both the movable plate 10 and the flat plate 11 are made entirely of metal, and the incident surface of the movable plate 10 is mirror-finished. Alternatively, both movable plates 10 and 11 use a semiconductor or !el, si body as a base material, and a metal film is deposited on this.

The diffraction grating is arranged so that it can receive the reflected light from the movable plate 10 and input the light into the output port section 9 through the lens 5-2.

The operation is as follows.

When no voltage is applied between the movable temporary 10 and the flat plate 11, the movable temporary 10 is not displaced, and the movable plate 10 reflects and diffracts the wavelength-multiplexed light (λ1 to λN), as shown by the solid line in FIG. Lattice 8
incident on .

The diffraction grating 8 demultiplexes the wavelength-multiplexed light, and inputs an optical signal of a single wavelength, for example, λ3, into the output boat section 9.

On the other hand, when a voltage is applied between the movable plate 10 and the flat plate 11, the voltage between them! #Electric power is applied, and the movable plate 10 is displaced as shown by the tightening in FIG. Due to this displacement, the movable plate 10 reflects the wavelength-multiplexed light in a direction different from that when no voltage is applied, as shown in the graph, and changes the incident condition on the diffraction grating 8.

This also changes the emission conditions of the diffraction grating 8, and an optical signal of another single wavelength, for example λ, of the wavelength multiplexed light enters the output boat section 9.

In this way, optical signals of different single wavelengths are incident on the output port section 9 according to the displacement of the movable plate 10.

The amount of displacement of the movable plate 10 of the optical deflection section is larger closer to its free end, and larger as the applied voltage is higher. Therefore, by controlling the applied voltage with the RI source 13 and changing the amount of displacement of the movable plate 10,
By changing the input and output conditions at the diffraction grating 8, the wavelength of the optical signal input to the output boat section 9 is controlled.

As described above, the optical deflection section is driven by electrostatic force and not driven by current, so it can be driven with low power.

Regarding the production of the optical wavelength selector, the optical deflection section consists of a movable plate 10, a flat plate 11, a support (insulator layer) 12-
1 and has a simple structure, as described in Reference 1 (K.
E. Petersen. “Dynamic Miero
mechanism on silieon;Te
chniques and devices
．． IEEE Transactions on ele
ctron deviees. vol. ED-25.
klO. By using etching technology, as shown in (1979), small-sized devices can be manufactured. Therefore, it is possible to produce an optical wavelength selector that is small and driven with low power.

Note that the support 12-1 may be a semiconductor layer since it is sufficient to support the movable plate 10 so as not to short-circuit between the conductive materials of the movable plate 10 and the flat plate 11. In this case as well, a small optical deflection section can be manufactured using etching technology as in the above-mentioned document 1.

Embodiment 2 FIG. 2 shows another embodiment of the present invention, which differs from FIG. 1 in the support structure of the movable plate 10 in the light deflection section.

In FIG. 2, the movable plate 10 is supported at both ends by supports 12-2 and 12-3 with an appropriate tension applied thereto, and the movable plate 10 is adjacent to and substantially parallel to the flat plate l1. The supports 12-2 and 12-3 are the supports 12-1 in the embodiment shown in FIG.
Similarly, it is an insulator layer or a semiconductor layer.

Except for the optical deflection section, the other structure is the same as that in FIG. 1, and an input port section 4,
Lens 5-1, diffraction grating 8, lens 5-2, output port section 9, movable plate 10, flat plate 11, movable plate support 12-2
．． 12-3, and DC voltage is applied between the movable plate 10 and the flat plate 11 by a voltage variable power source 13.

In addition, the input boat section 4 fixes an optical fiber that transmits wavelength-multiplexed light, and attaches a lens 5-1 to the surface of the movable 1ijlO.
The output port section 9 fixes an optical fiber or a photoelectric conversion element (for example, a photodiode), and receives the optical signal split by the diffraction grating 8 and passed through the lens 5-2. It is made incident. Of course, the surface of the movable plate 10 (at least the part on which the wavelength-multiplexed light is incident) has a function of reflecting the incident light.

The operation is as follows.

When a voltage is applied between the movable plate 10 and the flat plate 11, an electrostatic force acts therebetween, and the movable plate io is displaced as shown by the broken line of the second rgi. Due to the displacement of B, the movable plate 10 reflects the wavelength-multiplexed light in a direction different from that when no voltage is applied, as shown by the broken line, and changes the incident condition on the diffraction grating 8. As a result, the emission conditions of the diffraction grating 8 also change, and an optical signal of a single wavelength, for example, λ, which is different from that when no voltage is applied among the wavelength-multiplexed light, enters the output port section 9.

``In this way, optical signals of different single wavelengths are incident on the output port section 9 according to the displacement of the movable plate 10.

The amount of displacement of the movable plate 10 of the optical deflection unit shown in FIG. 2 is larger nearer to the center between the supporting points, and larger as the applied voltage is higher. Therefore, in the case of this embodiment as well, by controlling the applied voltage with the fl source 13 to change the amount of displacement of the movable plate 10 and changing the incident and output conditions at the diffraction grating 8, the light incident on the output port section 9 is Controls the wavelength of the signal.

The optical deflection section of this embodiment is also driven by electrostatic force and not driven by current, so it can be driven with low power.

Regarding the fabrication of the optical wavelength selector, the optical deflection section has a simple structure, consisting of a movable plate 10, a flat plate 11, and a support (insulator layer or semiconductor layer) 12-2, 12-3. The light deflection section of this embodiment also uses etching technology, etc., as described in the literature (J.A. van raalte.
^new Schliersnlight valve
for television project
n″.APPLIED OFrlCS.vol. 9.
HIL10. 1970), a small-sized one can be manufactured. Therefore, it is possible to produce a small optical wavelength selector that is driven by low power.

Effects of the Invention> As described above, in the optical wavelength selector of the present invention, the optical signal of the desired wavelength (channel) is controlled by controlling the direction of the light incident on the diffraction grating using the optical deflection section using electrostatic force. Since it is extracted from wavelength multiplexed light, it is not a current drive type, so it can be driven with low power, and has the advantage that component parts do not deteriorate due to heat generation.

Furthermore, by reflecting the incident light on the movable plate of the light deflecting section, the conditions of incidence on the diffraction grating can be controlled, so that the size can be reduced. Therefore, the optical wavelength selector of the present invention has the great advantages of being able to have low aS extinction and miniaturization.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing optical wavelength selectors according to embodiments of the present invention, respectively, and FIG. 3 is a diagram showing a conventional technique. In the drawing, 4 is an input boat part, 5-1 to 5-2 are lenses,
8 is a diffraction grating, 9 is an output boat part, 10 is a movable plate, 11
1 is a flat plate, 12-1 to 12-3 are supports, and 13 is a power source. Patent applicant Japan! Representative of Shindenwa Co., Ltd.

Claims (1)

[Claims] A movable plate that has a portion that reflects incident light on its surface and that is partially made of a conductive material and whose both ends or one end is supported by an insulator or semiconductor; It is composed of a light deflection section in which flat plates having a movable surface are arranged adjacent to each other in parallel with each other, and a diffraction grating into which the light emitted from the light deflection section is incident, and the voltage applied between the movable plate of the light deflection section and the flat plate is changed. An optical wavelength selector configured to take out an optical signal of a desired wavelength by controlling the incident and output conditions on the diffraction grating.