JPS6037503A - Light guide element - Google Patents

Abstract

PURPOSE:To facilitate the polishing of an end of an optical waveguide and to enable direct coupling by subjecting a part close to the end of the waveguide formed on a glass substrate by ion exchange to Ag<+> ion exchange to form a thicker ion exchanged layer. CONSTITUTION:A part close to an end of an optical waveguide 2 formed on a glass substrate 1 by K<+> ion exchange is subjected to Ag<+> ion exchange in an electric field to form a thicker Ag<+> ion exchanged layer 6. The polishing of the end is facilitated, and direct coupling is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention #1 relates to a light guide having an optical waveguide formed on a substrate, and particularly to a light guide that facilitates optical coupling at the ends of its elements.

(Prior art) A device in which a 19rgk portion is formed on the surface of a substrate such as glass by an ion exchange method to slightly increase the refractive index and a guiding waveguide is known. As a wholesaler, you can open a light switch using the thermo-optic effect. That is, as shown in FIG. 1, after forming an At thin film on the opposite side of a glass substrate 1 and forming a wave path shape, it was immersed in a KNO solution at 345° C. or higher for about 1 hour, and the second side of the substrate was heated. Exchange Na+ ions with Ni+ ions. In this way, the ion-exchanged portion 11 of the substrate also has a high refractive index of 4 to 6 x to -', and an optical waveguide is formed. The optical wave M created by K+ ion exchange has little change in refractive index even if it is lengthened, there is almost no leakage of guided light, and the propagation loss is 1 to 2 dB7cm, making it an excellent light guide element. It has been known.

However, the depth Ifll, 5~
It is 2 μm, and even if the ion exchange time is increased, it will not proceed to a deeper depth.

To make an optical switch, cut off the middle part of the optical wave path 81I3 as shown above without performing ion exchange o
So (D DJ WIT s 312) VC1T, ,
NiC.

A thin film 4 is formed by sputtering or steaming.

When light is input into the optical waveguide 2 in this state, the light is uJTh
It is diffused into the glass substrate at part 3 and does not enter the other optical waveguide 2'. However, when the wire mesh thin film 4 above the cut portion 3 is heated by electricity, the incident light is guided to the other optical waveguide 2'. When the temperature of glass increases by 100°C, a refractive index change of about 10-6 occurs, and this is the same as the refractive index difference between the optical waveguide and the substrate, so the optical waveguide 2.2'
This is because it becomes a situation that is connected in terms of price. The response speed k generated by such a thin film resistance heating element 4 is 0.5 maN.
# optical switches have been obtained.

In a device using an optical waveguide as described above, the question is how to input and output light.

Generally, as shown in FIG. 1, a prism coupling method using a prism 5 is adopted as a simple method. However, a device in which a plurality of optical switches are integrated at a high density has the disadvantage that the light spots are not clearly separated and the coupling efficiency with the prism varies.

In order to obtain direct input/output light from the end face of the red wave path, it is extremely difficult to polish the 0 part from the top surface of the substrate to 1.5 to 2 μn1 without sagging or chipping, and due to scattering at the end. F! I cannot get the desired pattern.

(!f!: purpose of light) This invention attempts to make the end face Q polishing easier by making ion exchange l- near the end face of the element, and to provide a light guide element that can be directly assembled. It's something.

(Creation of the Invention) The light guide element using the optical waveguide of the present invention is capable of ion exchange at least at the input and output end portions, as shown in FIG. 2 as a cross-sectional view along the optical waveguide and as shown in FIG. The layer is approximately 10 μnl ff1 degree V) deep and the end finish is d
It was made easy.

As mentioned above, the exchange layer due to IC+ ions is 1.5 to 2
Although it is only μm +=+i, Ag+ ions have the property of penetrating into a considerably thick part of the glass and performing ion exchange. The A, + ion-exchanged portion has a higher refractive index of 2 to 6 × 10 −2 than the glass substrate, and forms an optical waveguide similarly to the K+ ion exchange layer.

Ag+ ion exchange can also be performed by immersing the substrate in an AgNo solution, but better results can be obtained with electric field ion exchange.As shown in Figure 4, the end of the optical waveguide is The width of the optical waveguide (20 μm if facing) J!
An Ag film 7 having a length and a width of 1 μm is deposited. Next, A1 films for relaxation are formed on both sides of the substrate 1. When a suitable ground pressure is applied to this in a constant molding oven at 240° C., a wave path of 10 μm in diameter is formed, with Ag (on) entering the pan glass.

(Effects of the Invention) V) The invention provides the following advantages: A.
Oμmt184VLI2) Since the flat optical waveguide is made of cedar, it is easy to finish the input and output terminals, and the light can be sent to the bottom waveguide by just tapping the end by directing the light to the east end with a wide lens. −
You can emit a light spot directly from the song. 2-piece cedar shape, good separation, high output power, direct connection with fiber is possible, and a writable device with good spot shape, etc. , has a remarkable effect.

[Brief explanation of drawings]

FIG. 1 is a clear view of the operation of a light guide element using the conventional prism cube coupling method. The second factor is the light etc. of the light guide element of the present invention. Part along the path ~ 1 direction view, Figure 3, end view, Figure 4, explanatory diagram of Ag ion exchange method, Figure 1. Glass substrate 2: Optical waveguide 3: 9J section 4:
Thin film resistor 5 prism 6: Ag + ion exchange part 7: Ag film 8: At electrical insurance Applicant: Rico Co., Ltd. - Applicant's agent Patent attorney Fumi Sato (and 1 other person)

Claims (1)

[Claims] A light guide element in which an optical waveguide is formed on a glass substrate by ion exchange, in which at least the optical waveguide near the end face of the optical waveguide is made into a deep ion exchange layer by Ag ion exchange.