KR102506544B1 - Optical arrayed waveguide grating type multiplexer/demultiplexer - Google Patents

Abstract

An optical array waveguide lattice-type multiplexer and demultiplexer according to an embodiment includes a first substrate, a plurality of first waveguides overlapping and disposed on the first substrate in a vertical direction, which is a thickness direction of the first substrate, and a first one of the plurality of first waveguides. The 1-1 cladding layer disposed between the 1-1 waveguide closest to the substrate and the first substrate, the 1-2 cladding layer disposed between the plurality of first waveguides and the first substrate among the plurality of first waveguides and a first to third cladding layer disposed on the farthest first to second waveguide.

Description

Optical arrayed waveguide grating type multiplexer/demultiplexer

An embodiment relates to an optical array waveguide grating multiplexer and demultiplexer.

In order to transmit a lot of information in optical communication, a wavelength multiplexer transmission method is used. According to the wavelength multiplexer transmission method, light of different wavelength bands are multiplexed and transmitted.

In order to widen the wavelength band of the existing optical array waveguide lattice-type multiplexer and demultiplexer, it is inevitable to increase the size of the lattice-type multiplexer and demultiplexer of the optical array waveguide. However, when the size of the conventional optical array waveguide grating-type multiplexer and demultiplexer is large, it is difficult to apply to a small product and costs increase.

Embodiments provide an optical array waveguide lattice-type multiplexer and demultiplexer having a wide wavelength band without increasing the size.

An optical array waveguide lattice-type multiplexer and demultiplexer according to an embodiment may include a first substrate; a plurality of first waveguides overlapping and disposed on the first substrate in a vertical direction, which is a thickness direction of the first substrate; a 1-1 cladding layer disposed between the 1-1 waveguide closest to the first substrate among the plurality of first waveguides and the first substrate; first and second cladding layers disposed between the plurality of first waveguides; and a first to third cladding layer disposed on a first to second waveguide farthest from the first substrate among the plurality of first waveguides.

For example, the optical array waveguide grating-type multiplexer and demultiplexer may further include at least one first core disposed inside each of the plurality of first waveguides.

For example, the optical array waveguide lattice-type multiplexer and demultiplexer further include first-first and first-second free propagation regions spaced apart from each other in a horizontal direction orthogonal to the vertical direction and disposed on the first substrate; The 1-1, 1-2 and 1-3 cladding layers and the plurality of first waveguides may be disposed between the 1-1 and 1-2 free propagation regions.

For example, the optical array waveguide lattice-type multiplexer and demultiplexer may include at least one second waveguide disposed under the first substrate in the vertical direction; a 2-1st cladding layer disposed between the at least one second waveguide and the first substrate; and a 2-2 cladding layer disposed under the at least one second waveguide. The at least one second waveguide may include a plurality of second waveguides, and may further include a second-third cladding layer disposed between the plurality of second waveguides of the optical array waveguide lattice-type multiplexer and demultiplexer.

For example, the optical array waveguide grating-type multiplexer and demultiplexer may further include at least one second core disposed inside each of the second waveguides.

For example, the optical array waveguide lattice-type multiplexer and demultiplexer further include 2-1st and 2-2nd free propagation regions spaced apart from each other in a horizontal direction orthogonal to the vertical direction under the first substrate. The 2-1st and 2-2nd cladding layers and the at least one second waveguide may be disposed between the 2-1st and 2-2nd free propagation regions. The number of overlapping second waveguides in the vertical direction may be the same as or different from the number of overlapping first waveguides in the vertical direction.

According to another embodiment, the optical array waveguide lattice-type multiplexer and demultiplexer include a plurality of waveguide cells arranged to overlap each other in a vertical direction, each of the plurality of waveguide cells comprising: a substrate; a plurality of cladding layers disposed on the substrate; and a waveguide disposed between the plurality of cladding layers.

For example, the thickness of the substrate included in the upper first waveguide cell among the plurality of waveguide cells may be smaller than the thickness of the substrate included in the second waveguide cell disposed below among the plurality of waveguide cells. there is.

For example, each of the plurality of waveguide cells may further include at least one third core disposed inside the waveguide. Each of the plurality of waveguide cells further includes 3-1 and 3-2 free propagation regions spaced apart from each other in a horizontal direction orthogonal to the vertical direction on the substrate, and the plurality of cladding layers and the waveguide may be disposed between the 3-1 and 3-2 free propagation regions.

For example, the optical array waveguide lattice-type multiplexer and demultiplexer may further include a bonding portion for bonding the plurality of waveguide cells to each other. The at least one first, second or third core may include a total reflection material.

The optical array waveguide grating-type multiplexer and demultiplexer according to the embodiment may have a wide wavelength band without increasing the size.

1 is a view schematically showing appearances of an optical array waveguide lattice-type multiplexer and a demultiplexer according to an embodiment.
FIG. 2A is a cross-sectional view of the optical array waveguide lattice-type multiplexer and demultiplexer shown in FIG. 1 taken along the line A-A′, and FIG. 2B is an embodiment of the optical array waveguide lattice-type multiplexer and demultiplexer shown in FIG. 1 shows an embodiment of a cross-sectional view cut along line BB'.
FIG. 3A is a cross-sectional view of the optical array waveguide lattice-type multiplexer and demultiplexer along the line A-A′ shown in FIG. 1, and FIG. 3B is another embodiment of the optical array waveguide lattice-type multiplexer and demultiplexer shown in FIG. 1 shows another embodiment of a cross-sectional view cut along line BB'.
FIG. 4A is a cross-sectional view of the optical array waveguide lattice-type multiplexer and demultiplexer shown in FIG. 1 taken along the line A-A′, and FIG. 4B is another embodiment of the optical array waveguide lattice-type multiplexer and demultiplexer shown in FIG. Another embodiment of a cross-sectional view of the demultiplexer taken along line BB' is shown.
5A to 5D are process cross-sectional views for explaining a manufacturing method of the optical array waveguide lattice-type multiplexer and demultiplexer shown in FIG. 2A.
6A and 6B are cross-sectional views of an optical array waveguide lattice multiplexer and a demultiplexer according to a comparative example, respectively.
7 is a graph showing transmission efficiency for each wavelength.

Hereinafter, examples will be described in order to explain the present invention in detail, and will be described in detail with reference to the accompanying drawings to help understanding of the present invention. However, embodiments according to the present invention can be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

In the description of the embodiment according to the present invention, in the case of being described as being formed on the "upper (above)" or "under (on or under)" of each element, the upper (upper) or lower (lower) (on or under) includes both elements formed by directly contacting each other or by placing one or more other elements between the two elements (indirectly). In addition, when expressed as “up (up)” or “down (down) (on or under)”, it may include the meaning of not only the upward direction but also the downward direction based on one element.

In addition, relational terms such as "first" and "second", "upper/upper/upper" and "lower/lower/lower" used below refer to any physical or logical relationship or It may be used only to distinguish one entity or element from another, without necessarily requiring or implying an order.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of explanation. Also, the size of each component does not fully reflect the actual size.

1 is a diagram schematically illustrating appearances of an arrayed waveguide grating type multiplexer and demultiplexer 100 according to an embodiment.

The optical array waveguide grating multiplexer and demultiplexer 100 shown in FIG. 1 includes a first slap waveguide (or input mixing region) 110, an input waveguide 112, and a second slap waveguide (or output). mixing region) 120, an output waveguide 122, and a waveguide array 130.

The first slab waveguide 110 may serve as an input side of the optical array waveguide lattice-type multiplexer and demultiplexer 100 when the optical array waveguide lattice-type multiplexer and demultiplexer 100 operate as a demultiplexer that separates light. there is. On the other hand, when the optical array waveguide grating-type multiplexer and demultiplexer 100 operate as a multiplexer that combines light, the first slab waveguide 110 serves as an output side of the optical array waveguide grating-type multiplexer and demultiplexer 100. can be performed.

The second slab waveguide 120 may serve as an output side of the optical array waveguide lattice-type multiplexer and demultiplexer 100 when the lattice-type multiplexer and demultiplexer 100 operates as a demultiplexer. On the other hand, when the optical array waveguide lattice-type multiplexer and demultiplexer 100 operate as a multiplexer that combines light, the second slab waveguide 122 serves as an input side of the optical array waveguide lattice-type multiplexer and demultiplexer 100. can do.

One input waveguide 112 receiving light is connected to the input side of the first slab waveguide 110 . In contrast, a plurality of output waveguides 122 transmitting light may extend from the output side of the second slab waveguide 120 .

The waveguide array 130 may include a plurality of waveguides 132 . The plurality of waveguides 132 are arranged in parallel with each other and may take a 'U' shape. Light received through the input waveguide 112 is transmitted to the second slab waveguide 120 through the plurality of waveguides 132 .

In order for each of the plurality of waveguides 132 and the output waveguide 122 to propagate light, the refractive index of each of the waveguide 132 and the output waveguide 122 is higher than that of the first and second cladding layers described later. can Also, each of the plurality of waveguides 132 and the output waveguide 122 may be implemented with the same material. That is, the refractive indices of the plurality of waveguides 132 and the output waveguide 122 may be the same.

Also, each of the plurality of waveguides 132 and the output waveguide 122 may be implemented with a transparent material, for example, transparent plastic.

Also, the plurality of adjacent waveguides 132 may have different lengths. For example, adjacent waveguides 132 among the plurality of waveguides 132 may have a length difference by ΔL.

In the case of FIG. 1 , the number of waveguides 132 included in the waveguide array 130 is 4, but the embodiment is not limited thereto. That is, the number of waveguides 132 may be more or less than four.

The first slab waveguide 110 is disposed on the input side of the waveguide array 130, and the second slab waveguide 120 is disposed on the output side.

While the light emitted from the first slab waveguide 110 is transmitted to the second slab waveguide 120 via the waveguide array 130, the phase may be different for each wavelength. Thereafter, while the light passes through the second slab waveguide 120, the light may be separated for each wavelength.

FIG. 2A shows an embodiment 100A of a cross-sectional view of the optical array waveguide grating-type multiplexer and demultiplexer 100 shown in FIG. 1 cut along the line A-A′, and FIG. 2B is the optical array shown in FIG. 1 A cross-sectional view of the waveguide lattice-type multiplexer and demultiplexer 100 along the line B-B' shows an embodiment 100A.

Referring to FIGS. 2A and 2B , the optical array waveguide grating multiplexer and demultiplexer 100A includes a first substrate 210-1, a plurality of first waveguides 222-1 and 224-1, and a plurality of first claddings. Layers 232-1, 234-1, and 236-1, and first-first and first-second free propagation regions (FPRs) 110-1 and 120-1 may be included.

The plurality of first waveguides 222-1 and 224-2 may be vertically overlapped and disposed on the first substrate 210-1. Here, the vertical direction may be the thickness direction of the first substrate 210-1.

The first substrate 210-1 may be implemented with silicon, and the embodiment is not limited to a specific material of the first substrate 210-1.

The plurality of first waveguides 222-1 and 224-1 may include a 1-1 waveguide 222-1 and a 1-2 waveguide 224-1. Although the number of first waveguides is illustrated as two in FIGS. 2A and 2B, the embodiment is not limited thereto. That is, the following description may be applied even when the number of first waveguides is three or more.

Here, the 1-1 waveguide 222-1 is defined as a waveguide closest to the first substrate 210-1 among the plurality of first waveguides, and the 1-2 waveguide 224-1 is the plurality of first waveguides 224-1. It is defined as a waveguide furthest from the first substrate 210-1 among waveguides. That is, the 1-2nd waveguide 224-1 may be defined as a first waveguide positioned at the top among a plurality of first waveguides.

Meanwhile, the plurality of first cladding layers may include a 1-1 cladding layer 232-1, a 1-2 cladding layer 234-1, and a 1-3 cladding layer 236-1. Although the number of first cladding layers is illustrated as three in FIGS. 2A and 2B, the embodiment is not limited thereto. That is, even when the number of first cladding layers is 4 or more, the following description may be applied.

The 1-1 cladding layer 232-1 may be disposed between the 1-1 waveguide 222-1 and the first substrate 210-1.

The 1-2 cladding layer 234-1 may be disposed between the plurality of first waveguides. For example, as illustrated in FIGS. 2A and 2B , when the number of first waveguides is two, the 1-2 cladding layer 234-1 includes the 1-1 waveguide 222-1 and the 1-1 waveguide 222-1. It may be disposed between the two waveguides 224-1. 2A and 2B, since the number of first waveguides is two, the number of 1-2 cladding layers 234-1 is one, but when the number of first waveguides is 3, the number of 1-2 cladding layers ( 234-1) may be two.

The 1-3 cladding layer 236-1 may be disposed on the 1-2 waveguide 224-1.

Each of the 1-1 to 1-3 cladding layers 232-1, 234-1, and 236-1 may be plate shaped, but in the embodiment, the 1-1 to 1-3 cladding layers ( 232-1, 234-1, 236-1) is not limited to the specific shape. In addition, each of the first cladding layers 232-1, 234-1, and 236-1 may be implemented with a transparent material, for example, transparent plastic, or may be implemented with a polymer or SiO ₂ . In addition, the first cladding layers 232-1, 234-1, and 236-1 may be made of a material having a refractive index smaller than that of the waveguide 132 or the output waveguide 122.

Also, referring to FIG. 2B , the 1-1 and 1-2 free propagation regions 110-1 and 120-1 are spaced apart from each other in a horizontal direction orthogonal to the vertical direction and are formed on the first substrate 120-1. can be placed. Here, the 1-1 and 1-2 free propagation regions 110-1 and 120-1 may correspond to the first and second slab waveguides 110 and 120 shown in FIG. 1, respectively.

In this case, the first cladding layers 232-1, 234-1, and 236-1 and the plurality of first waveguides 222-1 and 224-1 form the 1-1 and 1-2 free propagation regions 110-2. 1, 120-1).

In addition, the optical array waveguide grating multiplexer and demultiplexer 100A shown in FIGS. 2A and 2B includes at least one first core (core) inside each of the plurality of first waveguides 222-1 and 224-1. 240-1) may be further included.

FIG. 3A is a cross-sectional view of another embodiment 100B of the optical array waveguide lattice-type multiplexer and demultiplexer 100 shown in FIG. 1 cut along line A-A', and FIG. A cross-sectional view of the waveguide lattice-type multiplexer and demultiplexer 100 along line B-B' shows another embodiment 100B.

Referring to FIGS. 3A and 3B , the optical array waveguide grating multiplexer and demultiplexer 100B includes a first substrate 210-1, a plurality of first waveguides 222-1 and 224-1, and a plurality of second waveguides. (222-2, 224-2), a plurality of first cladding layers (232-1, 234-1, 236-1), a plurality of second cladding layers (232-2, 234-2, 236-2), 1-1 and 1-2 free propagation regions (FPRs) 110-1 and 120-1, and 2-1 and 2-2 free propagation regions 110-2 and 120-2 may be included. there is.

Compared with the optical array waveguide grating multiplexer and demultiplexer 100A shown in FIGS. 2A and 2B, the optical array waveguide grating multiplexer and demultiplexer 100B shown in FIGS. 3A and 3B have a plurality of second waveguides 222 -2 and 224-2), the plurality of second cladding layers 232-2, 234-2 and 236-2, and the 2-1st and 2-2nd free propagation regions 110-2 and 120-2. contains more Except for this, the optical array waveguide grating multiplexer and demultiplexer 100B shown in FIGS. 3A and 3B are the same as the optical array waveguide grating multiplexer and demultiplexer 100A shown in FIGS. 2A and 2B, and thus have the same reference numerals. was used, and descriptions of overlapping parts are omitted.

The first waveguides 222-1 and 224-1, the first cladding layers 232-1, 234-1 and 236-1, and the first waveguides 222-1 and 224-1 are arranged vertically on the first substrate 210-1. The disposition of the -2 free propagation regions 110-1 and 120-1 is as described above with reference to FIGS. 2A and 2B.

In the case of the optical array waveguide grating multiplexer and demultiplexer 100B shown in FIGS. 3A and 3B , at least one second waveguide may be further disposed under the first substrate 210 - 1 in a vertical direction. The second waveguide may include a 2-1 waveguide 222-2 and a 2-2 waveguide 224-2. In the case of FIGS. 3A and 3B , the number of second waveguides is illustrated as two, but the embodiment is not limited thereto. That is, according to another embodiment, the number of second waveguides may be less than or greater than 2, and the following description may also be applied in this case.

Here, the 2-1st waveguide 222-2 is defined as a waveguide closest to the first substrate 210-1 among the second waveguides, and the 2-2nd waveguide 224-2 is the first of the second waveguides. It is defined as the farthest waveguide from the substrate 210-1. That is, the 2-2nd waveguide 224-2 can be defined as a waveguide positioned at the bottom among the second waveguides.

In addition, at least one second core 140-2 may be disposed inside each of the second waveguides 222-2 and 224-2.

Meanwhile, the plurality of second cladding layers may include a 2-1 cladding layer 232-2 and a 2-2 cladding layer 236-2. The 2-1st cladding layer 232-2 may be disposed between the 2-1st waveguide 222-2 and the first substrate 210-1. The 2-2nd cladding layer 236-2 may be disposed below the 2-2nd waveguide 224-2.

Also, when the number of second waveguides is plural, the plurality of second cladding layers may further include a second-third cladding layer 234-2. The 2-3 cladding layer 234 - 2 may be disposed between the plurality of second waveguides. For example, as illustrated in FIGS. 3A and 3B , when the number of second waveguides is two, the 2-3 cladding layer 234-2 includes the 2-1 waveguide 222-2 and the 2-1 waveguide 222-2. It may be disposed between the two waveguides 224-2. 3A and 3B, since the number of second waveguides is two, the number of 2-3 cladding layers 234-1 is one. 1) can be omitted.

Although the number of second cladding layers is illustrated as three in FIGS. 3A and 3B, the embodiment is not limited thereto. That is, the following description may be applied even when the number of second cladding layers is less than or equal to three.

Also, referring to FIG. 3B , the 2-1 and 2-2 free propagation regions 110-2 and 120-2 are spaced apart from each other in a horizontal direction orthogonal to the vertical direction and are below the first substrate 120-1. can be placed in

In this case, the second cladding layers 232-2, 236-2, and 234-2 and the plurality of second waveguides 222-2 and 224-2 form the 2-1 and 2-2 free propagation regions 110-2. 2, 120-2).

The 2-1 and 2-2 free propagation regions 110-2 and 120-2 are respectively shown in FIG. 1 like the 1-1 and 1-2 free propagation regions 110-1 and 120-1. corresponding to the first and second slab waveguides 110 and 120 respectively.

Also, the number of overlapping second waveguides in the vertical direction may be the same as the number of overlapping first waveguides in the vertical direction. For example, referring to FIGS. 3A and 3B , the number of vertically overlapping second waveguides 222-2 and 224-2 is equal to the number of vertically overlapping first waveguides 222-1 and 224-1. It can be seen that the number of and 2 are equal to each other.

Alternatively, the number of overlapping second waveguides in the vertical direction may be different from the number of overlapping first waveguides in the vertical direction. For example, unlike FIGS. 3A and 3B , the number of vertically overlapping second waveguides may be smaller than the number of vertically overlapping first waveguides.

FIG. 4A is a cross-sectional view of another embodiment 100C of the optical array waveguide grating-type multiplexer and demultiplexer 100 shown in FIG. 1 cut along the line A-A', and FIG. A cross-sectional view of the array waveguide lattice-type multiplexer and demultiplexer 100 along the line BB′ shows another embodiment 100C.

Referring to FIGS. 4A and 4B , the optical array waveguide lattice-type multiplexer and demultiplexer 100C may include a plurality of waveguide cells WC1 and WC2 disposed to overlap each other in a vertical direction. Here, the description is made on the assumption that the number of waveguide cells is two, but the following description can be applied even when the number of waveguide cells is greater than two.

Each of the plurality of waveguide cells WC1 and WC2 includes substrates 210-1 and 210-2, a plurality of cladding layers 232-1 and 234-1, at least one waveguide 222-1, and a third-1 and 3-2 free propagation regions 110-1 and 120-1.

Compared to the optical array waveguide grating multiplexer and demultiplexer 100A shown in FIGS. 2A and 2B, each of the waveguide cells WC1 and WC2 shown in FIGS. 4A and 4B is a 1-2 waveguide 224-1 and the first to third cladding layers 236-1. Except for this, since the waveguide cells WC1 and WC2 shown in FIGS. 4A and 4B are the same as the optical array waveguide lattice-type multiplexer and demultiplexer 100A shown in FIGS. 2A and 2B, respectively, the same reference numerals are used. , the overlapping parts are briefly reviewed as follows.

That is, in the optical array waveguide grating multiplexer and demultiplexer 100A shown in FIGS. 2A and 2B, each of the plurality of first waveguides 222-1 and 224-1 includes at least one first core 140-1. Similarly, the waveguide 222-1 in each of the waveguide cells WC1 and WC2 shown in FIG. 4A may further include at least one third core 140-1.

The first, second, or third cores 140-1 and 140-2 shown in FIGS. 2A, 3A, and 4A may be filled with air or a total reflection material. If the first, second, or third cores 140-1, 140-2 are filled with a total reflection material, the first or second waveguides 222-1, 224-1, 222-2, or 224-2 Light propagating through the first, second, or third cores 140-1 and 140-2 are totally reflected, thereby minimizing light loss.

In addition, similarly to the fact that the optical array waveguide lattice-type multiplexer and demultiplexer 100A shown in FIG. 2B includes the 1-1st and 1-2nd free propagation regions 110-1 and 120-1, it is shown in FIG. 4B. Each of the waveguide cells WC1 and WC2 has 3-1 and 3-2 free propagation regions 110-1 and 120-1 spaced apart from each other in the horizontal direction on the substrates 120-1 and 120-2. can include Since the 3-1 and 3-2 free propagation areas 110-1 and 120-1 are the same as the aforementioned 1-1 and 1-2 free propagation areas 110-1 and 120-1, respectively, Avoid redundant explanations.

In addition, the first thickness T1 of the substrate 210-1 included in the first waveguide cell WC1 disposed above the plurality of waveguide cells WC1 and WC2 is It may be thinner than the second thickness T2 of the substrate 210 - 2 included in the second waveguide cell WC2 disposed below. To this end, the lower surface of the substrate 210 - 1 may be polished before stacking the first waveguide cell WC1 on the second waveguide cell WC2 .

In addition, the lower surface of the substrate 210 - 2 included in the second waveguide cell WC2 may also be polished to reduce the second thickness T2 .

In addition, the plurality of waveguide cells WC1 and WC2 may be bonded to each other through the bonding portion 250 .

As shown in FIGS. 4A and 4B , when the plurality of waveguide cells WC1 and WC2 are vertically overlapped and disposed by the junction 250, the manufacturing process of the optical array waveguide lattice-type multiplexer and demultiplexer 100C is can be simplified

Hereinafter, a method of manufacturing the optical array waveguide grating-type multiplexer and demultiplexer 100A shown in FIG. 2A will be described as follows with reference to FIGS. 5A to 5D, but the embodiment is not limited thereto. That is, it goes without saying that the optical array waveguide grating multiplexer and demultiplexer 100A shown in FIG. 2A may be manufactured by a method other than the method shown in FIGS. 5A to 5D. In addition, it goes without saying that the optical array waveguide lattice-type multiplexers and demultiplexers 100A, 100B, and 100C shown in FIGS. 2B to 4B may be manufactured by applying the method shown in FIGS. 5A to 5D.

5A to 5D are cross-sectional views illustrating a method of manufacturing the optical array waveguide lattice-type multiplexer and demultiplexer 100A shown in FIG. 2A.

Referring to FIG. 5A , a 1-1 cladding layer 232-1 is formed on the first substrate 210-1. For example, the 1-1 cladding layer 232-1 may be formed on the first substrate 210-1 using a thermal oxidation process, but the embodiment is not limited thereto. The first substrate 210-1 may be formed using silicon, and the 1-1 cladding layer 232-1 may be formed using a polymer or SiO ₂ .

Then, referring to FIG. 5B , a material 222 for the 1-1 waveguide 222-1 is formed on the 1-1 cladding layer 232-1. For example, by depositing a material 222 having a relatively high refractive index, such as GeSiO2, on the 1-1st cladding layer 232-1 by chemical vapor deposition (CVD), the 1-1 waveguide ( 222-1) can be formed.

Subsequently, referring to FIG. 5C , a first core 240-1 is formed in the material 222 for the 1-1 waveguide 222-1. For example, the first core 240 - 1 may be formed by subjecting the material 222 to optical lithography and dry etching.

Then, referring to FIG. 5D , a 1-2 cladding layer 234-1 is formed on the 1-1 waveguide 222-1 on which the first core 240-1 is formed. For example, although the 1-2 cladding layer 234-1 may be formed using a material whose refractive index matches that of the 1-1 cladding layer 232-1 by chemical vapor deposition (CVD), Examples are not limited to this.

In addition, the first-second cladding layer 234-1 may be formed using a polymer or SiO ₂ .

Thereafter, the processes shown in FIGS. 5B to 5D are repeatedly performed to form the 1-2 waveguide 224-1, the 1st core 240-1, and the 1-3 cladding layer 236-1. can do.

Hereinafter, an optical array waveguide lattice-type multiplexer and demultiplexer according to comparative examples and embodiments will be described as follows with reference to accompanying drawings.

6A and 6B are cross-sectional views of an optical array waveguide lattice multiplexer and a demultiplexer according to a comparative example, respectively.

FIG. 6A is a cross-sectional view of a comparative example corresponding to FIG. 2A in which the optical array waveguide lattice-type multiplexer and demultiplexer 100 shown in FIG. 1 is cut along the line A-A', and FIG. A cross-sectional view of a comparative example corresponding to FIG. 2B in which the arrayed waveguide lattice-type multiplexer and demultiplexer 100 is cut along line BB′ is shown.

Referring to FIGS. 6A and 6B, the optical array waveguide lattice-type multiplexer and demultiplexer according to a comparative example include a substrate 10, cladding layers 22 and 24, a waveguide 30 and a core 40, free propagation regions ( 40, 42).

In the case of the optical array waveguide lattice-type multiplexer and demultiplexer according to comparative examples shown in FIGS. 6A and 6B , the size of the optical array waveguide lattice-type multiplexer and demultiplexer should be increased to widen a wavelength band.

7 is a graph showing transmission efficiency for each wavelength, wherein the horizontal axis represents the wavelength and the vertical axis represents the transmission efficiency. Here, FWHM (Full Width at Half Maximum) represents the full width at half maximum.

In order to widen the wavelength band, it can be seen through the following Equations 1 to 3 that the widths of the optical array waveguide grating-type multiplexer and demultiplexer of the comparative example are widened.

Here, Δλ _F represents the wavelength band of the optical array waveguide grating-type multiplexer and demultiplexer, N represents the number of waveguides included in the waveguide array, and Δλ represents the wavelength band of one waveguide. Also, Δλ has a relationship as shown in Equation 2 below.

Here, Δx represents the spacing between waveguides in the waveguide array of the optical array waveguide grating multiplexer and demultiplexer according to the comparative example, m represents the diffraction order, and L _f represents the focal length in the waveguide array where n _s represents the index in the slab guide, n _c represents the index in the arrayed guide, d represents the pitch length, and n _g represents the group refractive index (refractive index) and can be expressed as in Equation 3 below.

Here, λ ₀ represents the center wavelength shown in FIG. 7 .

On the other hand, in the case of the optical array waveguide lattice-type multiplexer and demultiplexer (100, 100A, 100B, 100C) according to the above-described embodiment, the waveguides 222-1 and 222 are formed by a semiconductor process without widening the wavelength band by increasing the size. -2, 224-1, 224-2) can be overlapped in the vertical direction to widen the wavelength band. In this way, when the waveguides are overlapped in the vertical direction, the wavelength band can be widened without increasing the width of the optical array waveguide grating-type multiplexer and demultiplexer, that is, without increasing the size of the optical array waveguide grating-type multiplexer and demultiplexer. . Therefore, the optical array waveguide lattice-type multiplexer and demultiplexer (100, 100A, 100B, 100C) according to the embodiment have a wide wavelength band, but the area they occupy is relatively smaller than that of the comparative example, so that they can be used in portable devices requiring small sizes such as mobile cell phones. It can be usefully used in electronic devices.

In addition, the optical array waveguide lattice-type multiplexer and demultiplexer according to the embodiment can widen the wavelength band without increasing the area, so that the wafer size is relatively reduced compared to the comparative example, so that the cost can be reduced. In addition, the image sensor generally uses a photodiode. In this case, an area detector using photodiodes in two dimensions can be used instead of a line detector using photodiodes in one dimension.

Although the above has been described with reference to the embodiments, these are only examples and do not limit the present invention, and those skilled in the art to which the present invention belongs will not deviate from the essential characteristics of the present embodiment. It will be appreciated that various variations and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

100, 100A, 100B, 100C: Optical array waveguide grating multiplexers and demultiplexers
110: first slab waveguide 110-1, 110-2, 120-1, 120-2: free propagation region
112: input waveguide 120: second slab waveguide
122: output waveguide 130: waveguide array
132, 222-1, 222-2, 224-1, 224-2: waveguide
120-1, 120-2: substrate
232-1, 232-2, 234-1, 234-2, 236-1, 236-2: cladding layer
240-1, 240-2: core 250: joint

Claims (15)

a first substrate;
a plurality of first waveguides overlapping and disposed on the first substrate in a vertical direction, which is a thickness direction of the first substrate;
at least two or more first cores disposed inside each of the plurality of first waveguides and spaced apart from each other on the same line in a horizontal direction crossing the vertical direction;
a 1-1 cladding layer disposed between the 1-1 waveguide closest to the first substrate among the plurality of first waveguides and the first substrate;
a 1-2 cladding layer disposed vertically spaced apart from the 1-1 cladding layer between the plurality of first waveguides; and
An optical array waveguide lattice-type multiplexer comprising a 1-3 cladding layer disposed on a 1-2 waveguide farthest from the first substrate among the plurality of first waveguides and spaced apart from the 1-2 cladding layer in a vertical direction. and a demultiplexer. delete The method of claim 1 , further comprising first-first and first-second free propagation regions disposed on the first substrate and spaced apart from each other in a horizontal direction orthogonal to the vertical direction,
The 1-1, 1-2, and 1-3 cladding layers and the plurality of first waveguides are optical array waveguides arranged between the 1-1 and 1-2 free propagation regions and form a grating multiplexer and demultiplexer. . According to claim 1, At least one second waveguide disposed in the vertical direction under the first substrate;
a 2-1st cladding layer disposed between the at least one second waveguide and the first substrate; and
The optical array waveguide lattice-type multiplexer and demultiplexer further comprising a 2-2 cladding layer disposed below the at least one second waveguide. 5. The method of claim 4, wherein the at least one second waveguide includes a plurality of second waveguides,
The optical array waveguide lattice-type multiplexer and demultiplexer further comprising second-third cladding layers disposed between the plurality of second waveguides. 5. The optical array waveguide grating-type multiplexer and demultiplexer according to claim 4, further comprising at least one second core disposed inside each of the second waveguides. 5. The method of claim 4, further comprising 2-1 and 2-2 free propagation regions spaced apart from each other in a horizontal direction orthogonal to the vertical direction under the first substrate,
The 2-1st and 2-2nd cladding layers and the at least one second waveguide are disposed between the 2-1st and 2-2nd free propagation regions. The optical array waveguide grating-type multiplexer and demultiplexer of claim 5, wherein the number of overlapping second waveguides in the vertical direction is the same as the number of overlapping first waveguides in the vertical direction. The optical array waveguide lattice-type multiplexer and demultiplexer of claim 5, wherein the number of overlapping second waveguides in the vertical direction is different from the number of overlapping first waveguides in the vertical direction. Including a plurality of waveguide cells arranged in an overlapping manner in a vertical direction;
Each of the plurality of waveguide cells is
Board;
a plurality of cladding layers arranged to be spaced apart from each other in a vertical direction on the substrate;
a waveguide disposed between the plurality of cladding layers; and
An optical array waveguide lattice-type multiplexer and demultiplexer comprising at least two or more cores disposed inside each of the waveguides and spaced apart from each other on the same line in a horizontal direction intersecting the vertical direction. 11. The method of claim 10, wherein a thickness of the substrate included in an upper first waveguide cell among the plurality of waveguide cells is greater than a thickness of the substrate included in a second waveguide cell disposed below among the plurality of waveguide cells. Thin optical array waveguide grating multiplexers and demultiplexers. delete 11. The method of claim 10, wherein each of the plurality of waveguide cells
Further comprising 3-1 and 3-2 free propagation regions spaced apart from each other in a horizontal direction orthogonal to the vertical direction on the substrate,
The plurality of cladding layers and the waveguide are arranged between the 3-1 and 3-2 free propagation regions, and the optical array waveguide lattice-type multiplexer and demultiplexer. 11. The multiplexer and demultiplexer according to claim 10, further comprising a bonding portion for bonding the plurality of waveguide cells to each other. The optical array waveguide grating-type multiplexer and demultiplexer according to any one of claims 1 to 6, wherein the at least one first or second core includes a total reflection material.

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