KR100389830B1 - Imaging apparatus and method for light distribution of planar waveguide circuit - Google Patents

Abstract

An apparatus for imaging a light distribution of a planar waveguide device according to the present invention comprises: a light source for emitting light of a predetermined wavelength; A planar waveguide element having a top surface scratched and having a waveguide coupled with the light; A light detector for outputting image data indicating a distribution of light propagating into the waveguide as the light scattered through the scratched upper surface of the waveguide is detected; And a display unit for outputting the image data on the screen.

Description

TECHNICAL APPARATUS AND METHOD FOR IMAGING LIGHT DISTRIBUTION OF PLANE WAVEGUIDE DEVICES

FIELD OF THE INVENTION The present invention relates to planar waveguide devices, and more particularly, to apparatus and methods for imaging the distribution of light propagating into the planar waveguide device.

Compared to the assembly of individual optical components, integrated optics technology, which is characterized by small size, low cost, low power consumption and high speed, has been constantly developed. Due to the process and price constraints of the composition of dielectric waveguides such as LiNbO ₃ and compound semiconductor optical waveguides such as GaAs and InP, the ripple effect on the actual communication field was weak compared to the active research activities. Recently, planar lightwave circuit (PLC) technology, which is formed of silica, which is a material such as an optical fiber, on a silicon substrate, and new bonding technology for light emitting / receiving devices have been proposed, thereby providing optical integration in the communication field. The practical use of technology is rapidly progressing. In fact, passive devices such as couplers, splitters, wavelength division multiplexing (WDM) devices, etc., have been commercialized mainly because of optical fiber type. In the case of high functional devices required by fiber to the home (FTTH), planar waveguide devices using semiconductor integrated circuit processing processes are considered to be excellent in terms of functionality as well as cost. For example, in the case of a splitter, the conventional optical fiber type is advantageous up to 1 × 4, but it is known that the planar waveguide device is advantageous when the number of branches increases more. The superiority of the planar waveguide device can be summarized by the small volume, mass production, and the possibility of low cost.

Meanwhile, the planar waveguide device needs a process of verifying that the planar waveguide device is manufactured according to design and process intention, and the characteristics of the planar waveguide device can be inferred by grasping the distribution of light traveling into the planar waveguide device. In addition, since it is extremely difficult to directly grasp such a distribution of light, conventionally, the characteristics of the planar waveguide device are measured by combining light into an input terminal of the planar waveguide device and measuring the light emitted from the output end of the planar waveguide device. Indirectly I have taken a way to figure it out. Therefore, according to the conventional method described above, a number of trials and errors are repeated until a target result is obtained, which leads to a problem in that a development period until obtaining a desired planar waveguide device is very long.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an apparatus and method capable of imaging the distribution of light propagating into a planar waveguide device.

In order to achieve the above object, an apparatus for imaging the light distribution of the planar waveguide device according to the present invention,

A light source for emitting light of a predetermined wavelength;

A planar waveguide element having a top surface scratched and having a waveguide coupled with the light;

A light detector for outputting image data indicating a distribution of light propagating into the waveguide as the light scattered through the scratched upper surface of the waveguide is detected;

And a display unit for outputting the image data on the screen.

In addition, the method for imaging the light distribution of the planar waveguide device according to the present invention,

Manufacturing a planar waveguide device by laminating a waveguide on which a top surface is scratched and a cladding surrounding the waveguide on a semiconductor substrate;

Coupling light into the waveguide;

Generating image data representing a distribution of light propagating into the waveguide as the light scattered through the upper surface of the waveguide is detected;

And visualizing the image data two-dimensionally.

1 is a view showing the configuration of an apparatus for imaging the light distribution of the planar waveguide device according to a preferred embodiment of the present invention,

FIG. 2 is a front view schematically showing the planar waveguide device shown in FIG. 1;

3 is a side cross-sectional view showing the planar waveguide device shown in FIG. 2 along Y-Y;

4 and 5 are views for explaining a method of manufacturing the planar waveguide device shown in FIG.

6 is a side cross-sectional view of the planar waveguide device shown in FIG. 2 along X-X;

7 is a flowchart illustrating a method of imaging a light distribution of a planar waveguide device according to a preferred embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

1 is a view showing the configuration of an apparatus for imaging the light distribution of the planar waveguide device according to a preferred embodiment of the present invention. 1 shows a light source 200, a convex lens 220, a planar waveguide device 100, an image intensifier 300, a light detector 400, and a display 500. have.

The light source 200 emits light 240 having a predetermined wavelength, and the light source 200 may use a tunable laser, a high power laser diode, or the like.

The planar waveguide element 100 is a Y-branch waveguide element, and is formed by forming a waveguide for forming an optical path on a semiconductor substrate and a cladding surrounding the waveguide.

FIG. 2 is a schematic front view of the planar waveguide device 100 shown in FIG. 1. The planar waveguide device 100 includes a semiconductor substrate, a waveguide 130 and a clad 150 stacked on the semiconductor substrate. The waveguide 130 includes an input waveguide 132 to which light 240 is coupled through one end thereof, a tapered waveguide 134 extending a mode of the input light 240, and the extended light. And a pair of output waveguides 136 for diverting the power of 240 and outputting through one end thereof. At this time, the upper surface of the waveguide 130, that is, the surface parallel to the semiconductor substrate and spaced farther from it, is uniformly scratched by a method such as fine sandpaper processing.

3 is a side cross-sectional view of the planar waveguide device 100 shown in FIG. 2 along Y-Y. As shown, the planar waveguide device 100 includes a semiconductor substrate 110 made of silica, a first cladding 120 made of silica, a waveguide 130 made of silica, and a second clad made of silica ( 150). As shown, the upper surface 139 of the waveguide 130 is artificially scratched (scratched), it is somewhat exaggerated in the drawings for ease of understanding. Such scratching is performed to the extent that light 240 traveling through the upper surface 139 of the waveguide into the waveguide 130 may cause scattering.

4 and 5 are views for explaining a method of manufacturing the planar waveguide device 100 shown in FIG. Hereinafter, a description will be given with reference to FIGS. 3 to 5.

Referring to FIG. 4, the first clad 120, the waveguide 130, and the photoresist layer 140 are sequentially stacked on the semiconductor substrate 110, and the waveguide 130 illustrated in FIG. 3 is formed. As the photoresist layer 140 is exposed using a mask having a slit, a pattern of the waveguide 130 as shown in FIG. 3 is formed in the photoresist layer 140. . Thereafter, the photoresist layer 140 as shown in FIG. 4 is formed through an etching process.

Referring to FIG. 5, the waveguide 130 is etched using the photoresist layer 140, and the photoresist layer 140 remaining on the waveguide 130 is removed using a photoresist removal liquid. Thereafter, the exposed top surface 139 of the waveguide 130 is sanded finely to form a waveguide 130 on which the top surface 139 is scratched, as shown in FIG. 5.

Thereafter, as illustrated in FIG. 3, the second clad 150 is stacked on the waveguide 130 and the exposed first clad 120.

FIG. 6 is a side cross-sectional view of the planar waveguide device 100 shown in FIG. 2 along X-X. As shown, the light 240 is coupled through one end of the waveguide 130, and the combined light 240 is repeatedly reflected from the upper surface 139 and the lower surface of the waveguide 130. At this time, a portion 260 of the light 240 incident on the upper surface 139 of the waveguide is scattered and is transmitted through the second clad 150 to be emitted to the outside atmosphere, which is the upper surface of the waveguide 130 ( 139) is scratched and does not satisfy the total reflection condition.

Referring back to FIG. 1, the light 240 having a predetermined wavelength output from the light source 200 is coupled to the input terminal of the planar waveguide device 100 by using the convex lens 220. A portion 260 is scattered on the upper surface 139 of the waveguide 130 and then transmitted through the second clad 150 to the outside atmosphere, and the remainder of the combined light 240 is the planar waveguide device 100. It is emitted through the output terminal of.

Scattered light 260 emitted from the planar waveguide device 100 is incident to the image intensifier 300 adjacent to the upper side of the planar waveguide device 100, and the image intensifier 300 is scattered light 260. This function improves the visibility of the image represented by). That is, the image intensifier 300 amplifies the intensity of the scattered light 260.

Scattered light 260 emitted from the image intensifier 300 is incident to the light detector 400, and the light detector 400 captures an image of the scattered light 260. A CCD camera may be used as the light detector 400, and the light detector 400 outputs image data 450 representing the scattered light image to the display 500, and the display 500 is shown. The scattered light image as shown is two-dimensionally visible on the screen 550. Since the scattered light image represents the light distribution in the planar waveguide device 100, it is possible to verify the characteristics of the planar waveguide device 100 through this.

In addition, although not shown, a predetermined lens system may be used to increase the power of the scattered light 260 input to the image intensifier 300.

7 is a flowchart illustrating a method of imaging a light distribution of a planar waveguide device according to an exemplary embodiment of the present invention. The method comprises a manufacturing process of a planar waveguide device, a light coupling process, a scattered light amplification process, an image data generation process, and a visualization process. Hereinafter, a description will be given with reference to FIGS. 1, 3 to 5, and 7.

In the manufacturing process 610 of the planar waveguide device 100, the waveguide 130 having the upper surface 139 scratched and the clads 120 and 150 surrounding the waveguide 130 are stacked on the semiconductor substrate 110. By doing so, the planar waveguide device 100 is manufactured.

The light combining process 620 is a process of combining the light 240 of a predetermined wavelength output from the light source 200 into the waveguide 130 using the convex lens 220.

The scattered light amplification process 630 uses the image intensifier 300 to scatter the light scattered from the upper surface 139 of the waveguide 130 and then to the outside atmosphere through the second clad 150. Amplification process.

The image data generating process 640 captures an image of the scattered light 260 emitted from the image enhancer 300 using the light detector 400, and generates image data 450 representing the scattered light image. It is a process.

The visualization process 650 is a process of two-dimensionally visualizing the scattered light image on the screen 550 using the display unit 500.

As described above, an apparatus and method for imaging light distribution of a planar waveguide device in accordance with the present invention captures and visualizes an image of light scattered through a scratched surface of the waveguide, whereby the light of the planar waveguide device represented by the scattered light image The advantage is that the distribution is known.

Claims (4)

In the device for imaging the light distribution of the planar waveguide device, A light source for emitting light of a predetermined wavelength; A planar waveguide element having a top surface scratched and having a waveguide coupled with the light; A light detector for outputting image data indicating a distribution of light propagating into the waveguide as the light scattered through the scratched upper surface of the waveguide is detected; And a display unit for outputting the image data on a screen. The method of claim 1, And an image intensifier positioned adjacent to the top of the planar waveguide element and amplifying the incident scattered light and outputting the scattered light to the photodetector. In the method for imaging the light distribution of the planar waveguide device, Manufacturing a planar waveguide device by laminating a waveguide on which a top surface is scratched and a cladding surrounding the waveguide on a semiconductor substrate; Coupling light into the waveguide; Generating image data representing a distribution of light propagating into the waveguide as the light scattered through the upper surface of the waveguide is detected; And visualizing the image data two-dimensionally. The method of claim 3, And amplifying the intensity of the scattered light emitted from the upper surface of the waveguide and emitted to the outside atmosphere through the cladding.