KR20220116842A - Multi-channel wavelength selective switching device for optical communication - Google Patents

Abstract

The present invention discloses a multi-wavelength selective switching device for optical communication, which selects phase Modulation. The multi-wavelength selective switching device includes: an optical fiber array including a plurality of optical fibers forming multiple channels and transmitting an optical signal for adding or dropping data for each optical fiber of each channel; and a reflective panel formed with an array of liquid crystal pixels which reflect a light signal. Therefore, it is possible to overcome manufacturing difficulties and produce devices for switching large amounts of data at a low cost.

Description

MULTI-CHANNEL WAVELENGTH SELECTIVE SWITCHING DEVICE FOR OPTICAL COMMUNICATION

The present invention relates to optical communication, and more particularly, to a multi-wavelength selective switching device for optical communication employing phase modulation.

An optical switch is used for high-speed and large-capacity data transmission over 5G, and the optical switch is configured to transmit information combined by wavelength division multiplexing to an optical fiber.

The above-described optical switch performs a function of taking data through a Reconfigurable Optical Add Drop Multiplexer (ROADM) or loading data through an optical fiber in a connection between networks or a backbone connection. At this time, taking data is expressed as "Drop", and loading data is expressed as "Add".

In this case, a channel switching technology is required, and a Wavelength Selective Switch (hereinafter, referred to as "WSS") is used as a core component of the ROADM.

WSS can use various light sources and needs to be designed to suit the needs of a large-capacity communication network that requires multiple inputs to multiple outputs.

A general WSS is configured to have a complex optical structure in order to transmit large-capacity data. Therefore, the WSS has a problem in that the economic burden is increased due to the difficulty in manufacturing.

And, the general WSS is configured such that one pixel and one optical fiber form a channel. The WSS of this structure has a problem in that the error rate increases due to insufficient light quantity for Add or loss occurring in the alignment of optical signals.

An object of the present invention is to provide a multi-wavelength selective switching device for optical communication suitable for the needs of a large-capacity communication network that requires connecting multiple inputs to multiple outputs by adopting phase modulation.

Another object of the present invention is to provide a multi-wavelength selective switching device for optical communication that can use various light sources and has a simple optical structure.

Another object of the present invention is to provide a multi-wavelength selective switching device for optical communication capable of reducing an error rate by having a switching structure corresponding to an optical signal of one channel and a plurality of pixels.

The multi-wavelength selective switching device for optical communication of the present invention includes a plurality of optical fibers forming a multi-channel, and transmits an optical signal for adding or dropping data for each optical fiber of each channel. fiber optic array; and a reflective panel having an array of liquid crystal pixels that reflect the light signal, wherein the liquid crystal pixels are configured such that S liquid crystal pixels are included in the irradiation region of the light signal, wherein S is a plurality of natural numbers, and The S liquid crystal pixels in the irradiation area have a reflection phase controlled to reflect the optical signal incident in a first channel formed by a first optical fiber to a second channel formed by a second optical fiber, The signal is reflected to the second channel by the S liquid crystal pixels.

In addition, the multi-wavelength selective switching device for optical communication of the present invention includes: a light source system for providing an optical signal; an optical fiber array including a plurality of optical fibers forming a multi-channel, and transmitting the optical signal for adding or dropping data for each optical fiber of each channel; a reflective panel having an array of liquid crystal pixels reflecting the light signal; and a polarization lens system configured between the optical fiber array and the reflective panel to transmit the optical signal between the multi-channel and the reflective panel, wherein the liquid crystal pixels include S liquid crystal pixels in the irradiated area of the optical signal. wherein S is a plurality of natural numbers, and the S liquid crystal pixels of the irradiation area transmit the optical signal incident from a first channel formed by a first optical fiber to a second optical fiber formed by a second optical fiber. It has a reflection phase controlled to be reflected in two channels, and the optical signal is reflected to the second channel by the S liquid crystal pixels.

The present invention includes a reflective panel having an array of liquid crystal pixels that reflect an optical signal, and is configured to control the reflection phase of the liquid crystal pixels using phase modulation.

Therefore, the present invention has the effect of connecting multiple inputs to multiple outputs suitable for a large-capacity communication network.

In addition, the present invention is configured to have a simple optical structure, thereby solving manufacturing difficulties and advantageously manufacturing a device for switching large-capacity data at low cost.

In addition, the present invention may use a variety of light sources that can be selected from ultraviolet, infrared, red, green, and blue. Therefore, there is an advantage that the optical signal can be transmitted efficiently.

And, the present invention is configured such that a plurality of reflective pixels are included in the irradiation area of the channel of one optical fiber. Therefore, there is an advantage in that the amount of light of the reflected optical signal can be sufficiently secured for the drop, and loss occurring in the alignment of the optical signal can be reduced. As a result, the present invention can be expected to reduce the error rate.

1 is a diagram showing a preferred embodiment of a multi-wavelength selective switching device for optical communication of the present invention.
2 is a diagram illustrating a cross-sectional structure of an example of an optical fiber array;
3 is a diagram illustrating a cross-sectional structure of another example of an optical fiber array.
Fig. 4 is a diagram for explaining control of a reflection phase of a reflection panel;
5 is a diagram illustrating a change in the Y-axis reference reflection phase of the reflection panel.
6 is a diagram illustrating a change in the X-axis reference reflection phase of the reflection panel.
FIG. 7 is a view illustrating that four liquid crystal pixels are included in a light signal irradiation area;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms used in the present specification and claims are not limited to a conventional or dictionary meaning, and should be interpreted in a meaning and concept consistent with the technical matters of the present invention.

The embodiments described in this specification and the configurations shown in the drawings are preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention, so various equivalents and modifications that can replace them at the time of the present application there may be

The present invention discloses a multi-wavelength selective switching device for optical communication employing phase modulation by using a reflective panel using liquid crystal on silicon (LCOS).

In general, LCOS is configured to drive liquid crystal pixels individually by using the properties of liquid crystal like the LCD driving principle, and reflects the incident light signal through a mirror under the liquid crystal, and the reflection phase of the liquid crystal pixel for reflection of the light signal can be controlled by the driving state of the liquid crystal.

An embodiment of the present invention includes a reflective panel having liquid crystal pixels configured using an LCOS capable of controlling the reflection phase as described above, and has a configuration for switching multiple inputs to multiple outputs using the reflective panel.

In the above embodiment, the phase modulation is achieved by individually controlling the liquid crystals of the liquid crystal pixels to have a reflection phase with respect to an incident light signal. The configuration of the above embodiment may be described with reference to FIG. 1 .

Referring to FIG. 1 , an embodiment of a multi-wavelength selective switching device for optical communication of the present invention is a light source system 10 , an optical fiber array 20 , a polarization lens system 30 , a reflection panel 40 , and a reflection control unit 50 . and a pattern generator 60 .

The light source system 10 is for providing an optical signal and may be configured using various light sources.

More specifically, the light source system 10 may be configured using a light source having a wavelength corresponding to one of ultraviolet rays, infrared rays, red, green, and blue.

In addition, the light source system 10 may be configured using two or more light sources as necessary, and the two or more light sources may be configured to have different wavelengths corresponding to ultraviolet, infrared, red, green, and blue.

Therefore, the embodiment of the present invention can use various light sources that can be selected from ultraviolet, infrared, red, green, and blue, so that an optical signal can be efficiently transmitted.

An embodiment of the present invention includes an optical fiber array 20 that carries an optical signal. The optical fiber array 20 includes a plurality of optical fibers forming a multi-channel, and is configured to transmit an optical signal for adding or dropping data for each optical fiber of each channel. In the embodiment of the present invention, data Add and Drop data based on the reflective panel 40 are designated by the controller 50 as a desired channel, and the optical fiber of other channels is added to the optical fiber designated as the Add channel. The data of the optical fiber is switched through the reflective panel 40 and added to transmit data, and the data of the optical fiber designated as a drop channel in the optical fiber array 20 is scanned by the reflective panel and transmitted to the switched optical fiber. Therefore, the channel selection of the optical fiber array 20 can be freely used by designating it in the ROADM control unit.

The optical fiber array 20 will be described in more detail with reference to FIGS. 1 to 3 .

The optical fiber array 20 may be composed of a bundle of a plurality of aggregated optical fibers. Each optical fiber 22 forms one channel. Therefore, it can be understood that the optical fiber array 20 includes a plurality of optical fibers and thus forms multiple channels.

In addition, each optical fiber 22 includes a core 24 and a clad 26 . The core 24 has a transparent material and provides a path for transmitting an optical signal, and may be preferably made of glass fiber. The clad 26 may be made of a material that physically protects the core 24 and totally reflects an optical signal transmitted through the core 24 to the core 24 . The core 24 may be manufactured to have a diameter of, for example, 8 μm to 12 μm, and the clad 26 may be manufactured to have a diameter of, for example, 125 μm.

The optical fiber array 20 includes a plurality of optical fibers having a cross-section arranged in a predetermined shape, and it may be understood that an outer shell is formed so that the plurality of optical fibers are bundled.

The plurality of optical fibers may form multiple channels of an MxN matrix structure having a cross section arranged in a quadrangular shape as shown in FIG. 2 or the multiple channels having a structure having a cross section arranged in a triangle as shown in FIG. 3 . Here, M and N are a plurality of natural numbers.

Each optical fiber of the optical fiber array 20 may transmit an optical signal for adding or dropping data.

That is, in the optical fiber array 20 , optical fibers of some channels may be used to add data, and optical fibers of other channels may be used to drop data. The number of optical fibers used for Add and Drop may vary.

An embodiment of the present invention includes a polarizing lens system 30 configured between an optical fiber array 20 and a reflective panel 30 . The polarizing lens system 30 may include combined lenses for transmitting optical signals between multiple channels of the optical fiber array 20 and the liquid crystal pixels of the reflective panel 40 . The polarizing lens system 30 guides the optical signal between the optical fiber array 20 and the reflective panel 40, and performs an optical action so that the optical signal can be focused on a specific liquid crystal pixel or a specific channel, which is a destination. can be understood as doing

In addition, the embodiment of the present invention includes a reflective panel 40 in which an array of liquid crystal pixels for reflecting an optical signal incident through the optical fiber array 20 is formed. In the drawings for explaining the present invention, an incident optical signal is denoted by AD, and a reflected optical signal is denoted by DR.

The reflective panel 40 may be described in more detail with reference to FIG. 4 .

In FIG. 4 , an array of liquid crystal pixels reflecting an optical signal is formed on the reflective panel 40 . Each liquid crystal pixel may be denoted by a symbol 40u. For example, each of the liquid crystal pixels 40u may have a rectangular shape, and the reflective panel 40 may be configured using liquid crystal on silicon (LCOS). Each of the liquid crystal pixels 40u may more preferably have a square shape.

The reflective panel 40 constructed using LCOS is configured to individually drive the liquid crystal pixels 40u using the properties of liquid crystal, and reflects the incident light signal through a mirror (not shown) under the liquid crystal, The reflection phase of each liquid crystal pixel 40u for reflection of the light signal may be controlled by the driving state of the liquid crystal.

Exemplarily, each liquid crystal pixel 40u includes a pair of electrodes (not shown) and a liquid crystal (not shown) between the electrodes, and the state in which the liquid crystal is arranged is changed in response to the potential difference between the electrodes, The arrangement state may be understood as determining a reflection direction, ie, a reflection phase, of an optical signal reflected through a mirror.

In the liquid crystal pixel 40u, the reflection phase may be changed with respect to the vertical Y-axis, the reflection phase may be changed with respect to the horizontal X-axis, or the reflection phase may be changed with respect to both the X-axis and the Y-axis.

The liquid crystal pixel 40a of FIG. 4 exemplifies that the reflection phase of the liquid crystal pixel 40u is changed based on the Y axis as shown in FIG. 5 , and the liquid crystal pixel 40b of FIG. 4 has the reflection phase of the liquid crystal pixel 40u in FIG. 6 is an example of a change based on the X-axis.

5 and 6 , it can be understood that the reflection phase of the liquid crystal pixel 40u is changed with respect to both the X-axis and the Y-axis.

Since the above-described driving method of the liquid crystal pixel 40u for changing the reflection phase corresponds to a general liquid crystal driving method, a detailed description thereof will be omitted.

In the embodiment of the present invention, the S liquid crystal pixels 40u are configured to be included in the irradiation area of the light signal. Here, S is a plurality of natural numbers, and FIG. 7 illustrates that four (S=4) liquid crystal pixels 40u are included in the irradiation area BA of one light signal.

Here, the irradiation area BA corresponds to a range through which the optical signal is irradiated. When the diameter of the core 24 of the optical fiber is 12 μm for example, it will be understood that the irradiation area BA of the optical signal incident through the core 24 has a diameter of 12 μm that is the same as the diameter of the core 24 . can

In addition, each of the liquid crystal pixels 40u configured in an array on the reflective panel 40 may be formed in a square having a side length of 3.6 μm, for example.

Therefore, as shown in FIG. 7 , four liquid crystal pixels 40u may be included in the irradiation area BA.

That is, in the embodiment of the present invention, an optical signal corresponding to one channel (eg, the first channel) may be incident on the core 24 of the optical fiber into the irradiation area BA including four liquid crystal pixels 40u. . In addition, the reflection phase of each of the four liquid crystal pixels 40u may be controlled to reflect the optical signal through another channel (eg, the second channel). As a result, the optical signal reflected by the four liquid crystal pixels 40u may be reflected to the other selected channel (the second channel).

That is, in the embodiment of the present invention, an optical signal of one channel is reflected by a plurality of liquid crystal pixels whose reflection phase is controlled, and as a result, the amount of light of the reflected optical signal for Add and Drop. It is a structure in which stability can be ensured enough to reduce loss that occurs in the alignment of optical signals in general.

Therefore, the embodiment of the present invention can relatively reduce an error rate.

In addition, the embodiment of the present invention may include a reflection control unit 50 as shown in FIG. 1 .

The reflection controller 50 controls the reflection phase of each liquid crystal pixel 40u for multiple channels. In addition, the reflection control unit 50 may individually control the reflection phase of the liquid crystal pixels 40u corresponding to the irradiation range BA so that the liquid crystal pixels 40u reflect the light signal to the second channel as described above.

A program for individually controlling the reflection phase of the liquid crystal pixels 40u may be set in the reflection control unit 50, and the reflection phase of the liquid crystal pixels for phase modulation may be differently controlled for each channel by the above program. have.

Therefore, it can be understood that the reflection control unit 50 has a function of controlling the phase modulation capable of connecting multiple inputs to multiple outputs suitable for a large-capacity communication network.

And, an embodiment of the present invention may include a pattern generator 60 for generating a pattern. The pattern generator 60 may generate information about a pattern of a diffraction grating pattern and provide it to the reflection controller 50 .

The reflection controller 50 may receive information about the pattern from the pattern generator 60 and control driving of the liquid crystal pixels 40u to form a pattern corresponding to the information.

Therefore, the reflective panel 40 may reflect the light signal by including at least a portion of the pattern formed on the liquid crystal pixels 40u.

The pattern generator 60 and the reflection control unit 50 of the present invention described above generally replaces a grating board using a physical diffraction grating pattern and a separate optical system for transmitting an image. . That is, the embodiment of the present invention can be configured to have a simple optical structure by the configuration of the pattern generator 60 and the reflection control unit 50, and can have the advantage of being easily manufactured, and parts that are reduced It can be manufactured so cheaply.

Claims (15)

an optical fiber array including a plurality of optical fibers forming a multi-channel and transmitting optical signals for data add or drop for each optical fiber of each channel; and
and a reflective panel on which an array of liquid crystal pixels reflecting the light signal is formed,
The liquid crystal pixels are configured such that S liquid crystal pixels are included in the irradiation area of the optical signal, wherein S is a plurality of natural numbers;
The S liquid crystal pixels of the irradiation area have a reflection phase controlled to reflect the optical signal incident from a first channel formed by a first optical fiber to a second channel formed by a second optical fiber,
and the optical signal is reflected to the second channel by the S liquid crystal pixels. The method of claim 1,
The plurality of optical fibers form the multi-channel of an MxN matrix structure having a cross-section arranged in a quadrangle, and wherein M and N are a plurality of natural numbers. The method of claim 1,
and wherein the plurality of optical fibers form the multi-channel structure having a cross section arranged in a triangle. The method of claim 1,
and a polarization lens system configured between the optical fiber array and the reflective panel and configured to transmit the optical signal between the multiple channels and the reflective panel. The method of claim 1,
Each of the liquid crystal pixels is composed of a rectangle,
The reflective panel is a multi-wavelength selective switching device configured using LCOS (Liquid Crystal On Silicon). 6. The method of claim 5,
Each of the liquid crystal pixels is a multi-wavelength selective switching device configured in a square shape. The method of claim 1,
The liquid crystal pixels are configured such that the four liquid crystal pixels are included in the irradiation area of the light signal,
wherein the four liquid crystal pixels have the reflection phase individually controlled to reflect the optical signal to the second channel. The method of claim 1,
It further comprises a reflection control unit;
The reflection control unit controls the reflection phase for the multiple channels, and individually controls the reflection phase of the liquid crystal pixels so that the liquid crystal pixels corresponding to the irradiation range reflect the light signal to the second channel. Wavelength selective switching device. 9. The method of claim 8,
a pattern generator for generating a pattern;
The reflection control unit receives information about the pattern from the pattern generator, forms the pattern corresponding to the information on the liquid crystal pixels, and includes at least a part of the pattern to reflect the optical signal. Selective switching device. 10. The method of claim 9,
wherein the pattern generator generates and provides the information about the pattern of a diffraction grating fringe. The method of claim 1,
Further comprising a light source system for providing the optical signal to the optical fiber array,
The light source system is a multi-wavelength selective switching device using a light source having a wavelength corresponding to one of ultraviolet, infrared, red, green, and blue. The method of claim 1,
Further comprising a light source system for providing the optical signal to the optical fiber array,
The light source system uses two or more light sources,
wherein the two or more light sources have different wavelengths corresponding to ultraviolet, infrared, red, green and blue multi-wavelength selective switching device. a light source system providing an optical signal;
an optical fiber array including a plurality of optical fibers forming a multi-channel, and transmitting the optical signal for adding or dropping data for each optical fiber of each channel;
a reflective panel having an array of liquid crystal pixels reflecting the light signal; and
and a polarization lens system configured between the optical fiber array and the reflective panel to transmit the optical signal between the multi-channel and the reflective panel.
The liquid crystal pixels are configured such that S liquid crystal pixels are included in the irradiation area of the optical signal, wherein S is a plurality of natural numbers;
The S liquid crystal pixels of the irradiation area have a reflection phase controlled to reflect the optical signal incident from a first channel formed by a first optical fiber to a second channel formed by a second optical fiber,
and the optical signal is reflected to the second channel by the S liquid crystal pixels. 14. The method of claim 13,
It further comprises a reflection control unit;
The reflection control unit controls the reflection phase for the multiple channels, and individually controls the reflection phase of the liquid crystal pixels so that the liquid crystal pixels corresponding to the irradiation range reflect the light signal to the second channel. Wavelength selective switching device. 9. The method of claim 8,
a pattern generator for generating a pattern;
The reflection control unit receives information about the pattern from the pattern generator, forms the pattern corresponding to the information on the liquid crystal pixels, and includes at least a part of the pattern to reflect the optical signal. Selective switching device.

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