JPH07159636A - Waveguide optical component and adjusting method thereof - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] A waveguide type optical component and a method of adjusting the same, wherein a waveguide element configured to facilitate coupling with an optical fiber and the optical fiber coupled to the waveguide element. It aims at providing the adjustment method at the time of doing. An underclad layer 2 is provided on a substrate 1, a ridge-shaped core 3 corresponding to a waveguide pattern is provided on the underclad layer 2, and the underclad layer 2 and the core 3 are covered to form an overclad layer. 4 is provided, a metal pattern 6 corresponding to the waveguide pattern is provided on the overclad layer 4 on the quartz optical waveguide substrate 5 to form a waveguide element, and the waveguide element and the optical fiber are coupled. Then, when the waveguide optical component is formed, alignment is performed with the metal pattern 6 as a reference, thereby facilitating optical axis alignment between the core 3 and the optical fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide type optical component and a method for adjusting the same, and more particularly to a waveguide type optical component constructed so as to facilitate coupling with an optical fiber, and this waveguide type optical component. The present invention relates to an adjusting method when coupling optical fibers.

When an optical circuit is constructed, a desired optical circuit is constructed by coupling a waveguide element having various optical elements made of an optical waveguide on a substrate and a transmission line made of an optical fiber. In general, various waveguide type optical components have been proposed.

Such a waveguide type optical component is such that the adjustment work at the time of coupling with the optical fiber is easy, it does not need to rely on a skilled worker, and does not require much adjustment time. Is required.

[0004]

2. Description of the Related Art FIG. 7 exemplifies a conventional waveguide type optical component, and shows a case of a quartz optical waveguide using a guide groove. In FIG. 7, reference numeral 61 is a silicon wafer, and an optical waveguide portion 63 is formed in a deposited glass film 62 provided thereon. Reference numerals 64 _1, 64 _2, 64 ₃ are guide grooves having a depth and a width adapted to the optical fiber, and corresponding to the end portions 65 _1, 65 _2, 65 ₃ of the optical waveguide portion 63, the deposited glass film 62 is formed. It is formed by etching.

In such a waveguide element, in order to couple the optical waveguide and the optical fiber, the guide grooves 64 _1, 6 are used.
Optical fibers 66 _1, 66 _2, 6 whose end faces are polished to 42 _, 64 _3.
After embedding 6 ₃ respectively and aligning the optical axes of the optical waveguide and the optical fiber, the ends of the optical fiber are adhered and fixed by UV (ultraviolet) curable adhesives 67 _1, 67 _2, 67 ₃ . .

As another method, an optical fiber is adhered to the V-groove array, the end face thereof is polished, and then the mutual positions of the waveguide element and the V-groove array are adjusted to adjust the optical waveguide and the optical fiber. There is a method of aligning the optical axes of and and then fixing both.

In the method of coupling the optical waveguide and the optical fiber by using the guide groove, for example, in the case of the quartz optical waveguide, the variation of the deposited glass film thickness formed by the flame hydrolysis method and the guide groove formed by the etching process are used. It is difficult to connect the optical waveguide and the core of the optical fiber with high accuracy due to variations in depth of the optical fiber.

Therefore, an optical fiber in which the waveguide element is adhered and fixed to a package or the like, and the end face is polished by adhering to the core,
After adjusting its position using the fine movement stage, aligning the optical axes of the waveguide element and the optical fiber, and then bonding them together,
Alternatively, a method of making a connection by welding is used.

[0009]

However, when the positional relationship between cores having an outer diameter of about 8 μm is adjusted due to variations in the bonding position and variations in the created optical waveguide outer dimensions, adjustment work is required. In addition to having to rely on a skilled worker, it requires a lot of adjustment time and lacks mass productivity.

This is because both the core portion and the cladding portion of the waveguide element are made of glass and the difference in the refractive index between them is small, so that the waveguide element and the optical fiber are enlarged during the adjustment work. It is a major cause that the core part of the waveguide element is difficult to see on the screen of the monitor TV to be displayed.

The present invention is intended to solve the problems of the prior art as described above, and a pattern made of metal is formed on the waveguide pattern of the waveguide element so that the core portion can be easily recognized. By doing so, when connecting the waveguide element and the optical fiber, the purpose is to make it possible to easily and highly accurately adjust the optical axis alignment.

[0012]

Means for Solving the Problems (1) In a waveguide element of the present invention, an underclad layer 2 is provided on a substrate 1, and a ridge-shaped core 3 corresponding to a waveguide pattern is provided on the underclad layer 2. At the same time, in the quartz optical waveguide substrate 5 in which the over cladding layer 4 is provided so as to cover the under cladding layer 2 and the core 3, the metal pattern 6 corresponding to the waveguide pattern is provided on the over cladding layer 4.

(2) In the case of (1), the metal pattern 6 is made of an aluminum (Al) film.

(3) In the waveguide type optical component of the present invention, in the case of (1) or (2), the waveguide element is housed and fixed in a metal package, and the optical fiber is aligned with the optical axis with respect to the core. It is configured by fixing together.

(4) According to the method of adjusting a waveguide type optical component of the present invention, an under clad layer is provided on a substrate, and a ridge-shaped core corresponding to a waveguide pattern is provided on the under clad layer, and an under clad layer is further formed. For a waveguide element in which a metal pattern corresponding to the waveguide pattern is provided on the overclad layer in a quartz optical waveguide substrate in which the overclad layer is provided so as to cover the cladding layer and the core, the metal pattern and the optical fiber The optical axis of the core and the optical fiber is aligned by adjusting the relative position between the core and the optical fiber.

[0016]

A waveguide pattern having the same width as or a slightly wider width than the core is formed of a metal material on the quartz optical waveguide substrate formed by the flame hydrolysis method and the reactive ion etching method. After that, the waveguide frame embedded in the clad formed by the reactive etching method is cut by dicing,
Create individual waveguide elements.

The connection between the waveguide element and the optical fiber is made as follows. First, the waveguide element is bonded to a package or the like. Next, the package to which the waveguide element is bonded is attached to the adjustment jig. An image recognition device is provided above the adjustment jig, and the position of the core inside the waveguide element is detected by reading the waveguide pattern made of a metal material drawn on the waveguide. In this way, the interface optical fiber can be easily adjusted to the initial position by defining the core position.

Therefore, according to the present invention, in the waveguide type optical component, the optical axes of the waveguide element and the optical fiber can be easily adjusted with high accuracy.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of a waveguide device according to an embodiment of the present invention. Reference numeral 1 is a substrate made of a silicon wafer or quartz glass or the like, on which an underclad layer 2 is provided. A ridge-shaped core 3 having a shape corresponding to the waveguide pattern is provided on the underclad layer 2. Further, the quartz optical waveguide substrate 5 is formed by providing the over cladding layer 4 so as to cover the under cladding layer 2 and the core 3.

For such a quartz optical waveguide substrate 5,
A metal pattern 6 corresponding to the core 3 is provided on the overclad layer 4. The metal pattern 6 has the same shape as the waveguide pattern, and its width is the same as or slightly wider than that of the core 3. Since the metal pattern 6 is provided right above the core 3, the metal pattern 6 can be aligned with the core 3 by adjusting the position with the metal pattern 6 as a reference when aligning with the optical fiber.

FIG. 2 shows the structure of a waveguide type optical component in an embodiment of the present invention. Reference numeral 7 is a waveguide element of the present invention, on which a metal pattern 8 is shown. The waveguide element 7 is housed and fixed inside a metal package 9 made of SUS (stainless steel) or the like. Optical fibers 10 _{1 and} 10 ₂ are housed and fixed in the cores 11 _{1 and} 11 ₂ , respectively. The cores 11 _{1 and} 11 ₂ are fixed to the metal package 9. The optical fibers 12 _{1 and} 12 ₂ of the optical fiber cables 10 _{1 and} 10 ₂ are coupled to the core (not shown) under the metal pattern 8 by aligning the optical axes.

FIG. 3 shows an example of the structure of the core. Reference numeral 10 denotes an optical fiber cable, which is coated with a resin. Reference numeral 11 denotes a core made of SUS or the like, which has a structure capable of holding and fixing the optical fiber cable 10 and leading out the optical fiber 12 from one end thereof. The end face 13 of the optical fiber 12 is mirror-polished in preparation for coupling with the waveguide element.

FIG. 4 shows a method of manufacturing a waveguide element according to an embodiment of the present invention, in which (a) is an underclad layer and a core layer, (b) is a resist coating, c) shows the steps of exposure, (d) shows the steps of etching, (e) shows the steps of depositing the over cladding layer, and (f) shows the completed wafer of the quartz optical waveguide substrate. Also,
(G) shows deposition of an aluminum layer, (h) shows resist coating, (i) shows exposure, (j) shows etching steps, and (k) shows a completed waveguide element wafer. .

First, on a substrate 21 made of a silicon wafer or quartz glass, etc., by a flame hydrolysis method,
As shown in (a), a glass layer including an underclad layer 22 and a core layer 23 is formed. At this time, in the formed glass layer, the relative refractive index difference between the under cladding layer 22 and the core layer 23 is 0.75%, and the thickness of the core layer 23 is 6 μm.

Next, a waveguide pattern having a width of 6 μm and a frame for cutting the waveguide having a width of 100 μm are formed by the photolithography technique and the reactive ion etching method. That is, as shown in (b), the core layer 2
3 is coated with a resist layer 24 on the entire surface, exposed and developed to form a resist 25 serving as a mask as shown in FIG.
Leave. By further etching, (d)
As shown in FIG. 5, the core layer other than the resist 25 is removed to form a ridge-shaped core 26 and a frame 27.
After that, the flame hydrolysis method is used to form the overclad layer 28 on the entire upper surface, thereby completing the wafer 29 of the quartz optical waveguide substrate as shown in (f).
In the wafer 29 of the quartz optical waveguide substrate, 30 is a waveguide and 31 is a frame.

Next, as shown in FIG. 3G, about 2 is formed on the upper portion of the wafer 29 of the quartz optical waveguide substrate by the vacuum deposition method.
An aluminum (Al) thin film 32 having a thickness of 000Å is formed. After that, a resist layer 33 is applied on the entire surface, and as shown in (i), a resist 34 having a waveguide pattern with a width of 10 μm is exposed and developed by a chromium (Cr) mask or the like. Finally, etching with phosphoric acid solution,
As shown in (j), by forming an aluminum thin film pattern 35 formed in a waveguide pattern,
The waveguide device wafer 36 as shown in (k) is completed. In the wafer 36 of the waveguide element, 37 is an aluminum thin film pattern.

Then, in the wafer 36 of the waveguide device, the frame 31 formed inside the clad glass is used.
Are cut by a dicing operation to form individual waveguide elements.

FIG. 5 shows an outline of the optical axis adjusting device. In the figure, 41 is a metal package for fixing the waveguide element, 42 is a package fixing part for fixing the metal package 41, 43 and 44 are optical fiber adjusting parts for adjusting the positions of the optical fibers 45 and 46, and 47 is A CCD camera for capturing an image of the waveguide element and the optical fiber, 48 is a monitor TV for displaying the image of the CCD camera 47, 49 is an LED light source for inputting light to one optical fiber 45, and 50 is It is an optical power meter for measuring the intensity of the output light of the other optical fiber 46.

The package fixing portion 42 has three parts of X, Y and Z.
It is configured to be movable in the axial direction. Further, the two systems of optical fiber adjusting units 43 and 44 are configured to be movable in three axial directions of X, Y, and Z, and to be capable of giving tilt angles θ and φ in the horizontal direction and the vertical direction, respectively. Has been done.

FIG. 6 shows an optical axis adjustment method for a waveguide type optical component according to an embodiment of the present invention, in which the optical axes of the optical fiber 45 and the waveguide element shown in FIG. 5 are adjusted. Is shown and explained by the image on the monitor screen.
In the figure, (a) shows a state in which a metal package, a waveguide element attached to the metal package, and an optical fiber cable are set in an optical axis adjusting device, and (b) shows a state of measuring the amount of axis deviation between the metal pattern and the optical fiber. (C) shows a state in which the axis deviation is corrected, (d) shows a state in which the waveguide element and the optical fiber are arranged close to each other, and (e) shows a state in which the waveguide element and the optical fiber are bonded and fixed.

In FIG. 6, A indicates a monitor screen. The waveguide element 51 is adhesively fixed to a metal package 52 made of SUS or the like, and the metal package 52 is fixed to the package fixing portion 42 shown in FIG. The optical fiber cable 53 is housed in a core 54 made of SUS or the like and fixed by adhesion, and the core 54 is fixed to the optical fiber adjusting section 43 shown in FIG. In FIG. 6, (a)
Shows the state in which the waveguide element 51 and the optical fiber cable 53 are initially set in this way.
The end surface of the optical fiber 55 is previously polished.

First, the amount of misalignment between the metal pattern 56 on the waveguide element 51 and the optical fiber 55 is measured on the screen. In (b), the deviation amount ΔX is, for example, 0.
It was shown that it was 38 (mm).

Next, as shown in (c), the optical fiber adjusting section 43 is moved in the Y direction shown in the figure to make a correction so that the axes of the metal pattern 56 and the optical fiber 55 are aligned on the screen. To do. At this time, the metal package 52 has holes 5 so that the core 54 can be moved without touching.
7 is provided.

Next, as shown in (d), the optical fiber adjusting section 43 is moved in the X direction shown in the drawing to guide the waveguide element 51.
And the end face of the optical fiber 55 are arranged close to each other at a predetermined distance.

The optical axes of the other optical fibers 46 shown in FIG. 5 can be adjusted in the same manner by using the optical fiber adjusting section 44.

Next, the LED light source 4 in the optical axis adjusting device
9 and the optical power meter 50 are operated, and the optical fiber adjustment unit 43 is finely moved in each direction so that the detection level in the optical power meter 50 becomes maximum. Note that (d)
In the adjustment up to the stage, the Z direction is not adjusted, but since the axis deviation is corrected to some extent by adjusting the Y direction and the X direction, it is possible to immediately shift to the optical adjustment. it can.

After the optical axis adjustment is completed in this way,
The end face of the optical fiber 55 and the portion of the core which forms the waveguide pattern and is located directly below the metal pattern 56 are
The V-curing type adhesive 58 is used to adhere and fix. At this time, the core 54 is also bonded and fixed to the metal package 52.

[0038]

As described above, according to the present invention, since the metal pattern is formed on the waveguide pattern in the waveguide element, by using this metal pattern,
The position of the waveguide pattern can be easily recognized as image information, and therefore, the optical axis adjustment with the optical fiber in the waveguide type optical component can be easily performed in a short time.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a waveguide element according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a waveguide type optical component according to an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration example of a core.

FIG. 4 is a diagram showing a method of manufacturing a waveguide element according to an embodiment of the present invention, in which (a) is formation of an underclad layer and a core layer, (b) is resist coating, and (c) is exposure. ,
(D) shows each process of etching, (e) shows the process of depositing an over clad layer, (f) has shown the wafer of the completed quartz optical waveguide substrate. Further, (g) is an aluminum layer deposition, (h) is a resist coating, (i) is exposure,
(J) shows each process of etching, (k) shows the wafer of the completed waveguide device.

FIG. 5 is a diagram showing an outline of an optical axis adjusting device.

FIG. 6 is a diagram showing an optical axis adjustment method for a waveguide type optical component according to an embodiment of the present invention, in which (a) is an optical axis adjustment of a metal package, a waveguide element attached to the metal package, and an optical fiber cable. The state of being set in the device, (b) the state of measuring the amount of misalignment between the metal pattern and the optical fiber, (c) the state of correcting the misalignment, (d) the waveguide element and the optical fiber being arranged in proximity. The state, (e) shows the state where the waveguide element and the optical fiber are bonded and fixed.

FIG. 7 is a diagram illustrating a conventional waveguide type optical component.

[Explanation of symbols]

 1 Substrate 2 Undercladding Layer 3 Core 4 Overcladding Layer 5 Quartz Optical Waveguide Substrate 6 Metal Pattern

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location 7139-2K G02B 6/24 301

Claims (4)

[Claims] 1. An underclad layer (2) is provided on a substrate (1), a ridge-shaped core (3) corresponding to a waveguide pattern is provided on the underclad layer (2), and the underclad layer is also provided. In a quartz optical waveguide substrate (5) provided with an overclad layer (4) covering (2) and a core (3), a metal pattern (corresponding to the waveguide pattern on the overclad layer (4) ( 6) is provided, The waveguide element characterized by the above-mentioned. 2. The waveguide element according to claim 1, wherein the metal pattern (6) is made of an aluminum (Al) film. 3. The waveguide element (7) is housed and fixed in a metal package (9), and an optical fiber (10) is provided.
_The waveguide type optical component according to claim 1 or 2, characterized in that _1, 11 ₂ ) are fixed to the core (3) with their optical axes aligned. 4. An under clad layer is provided on a substrate, a ridge-shaped core corresponding to a waveguide pattern is provided on the under clad layer, and an over clad layer is provided to cover the under clad layer and the core. In a quartz optical waveguide substrate made of the above, by adjusting the relative position of the metal pattern and the optical fiber with respect to the waveguide element in which a metal pattern corresponding to the waveguide pattern is provided on the overclad layer, A method of adjusting a waveguide type optical component, which comprises aligning an optical axis between a core and an optical fiber.