JPS60145933A - Manufacture of embedded form plate microlens - Google Patents

Abstract

PURPOSE:To manufacture the titled lens capable of bonding many optical fibers efficiently to other optical fibers, by diffusing a substance capable of increasing the refractive index thermally into a heated part of a substrate heated locally by irradiation with laser beams. CONSTITUTION:A surface for forming a microlens on a quarts or silicon substrate 3 is wrapped with a gas 2 of a substance, e.g. GeCl4, of about several tens of nm thickness capable of increasing the refractive index. The substrate 3 is then irradiated perpendicularly with laser beams 1 having controlled spot size and power and locally heated to about the melting point thereof to diffuse the substance, e.g. Ge, pyrolyzed from the gas 2 thermally into the surface of the substrate 3 and form a plate microlens having a refractive index distribution 5 proportional to the temperature distribution 4.

Description

[Detailed Description of the Invention] fat Technical Field of the Invention The present invention relates to a method for manufacturing an embedded flat plate microlens, and in particular to a method for manufacturing an embedded flat plate microlens, in particular, by locally heating a substrate made of a quartz substrate, a silicon plate, etc. with controlled laser light. The present invention relates to a method of manufacturing an embedded flat microlens with an increased refractive index.

(b) Technical background In recent years, with the rapid development of optical fibers, optical communications,
It is well known that it is being widely applied to optical information processing and the like. Therefore, there is a strong demand for the development of embedded flat microlenses and embedded flat microlens arrays that can efficiently couple a large number of optical lenses with other optical devices.

(c+ Problems with the conventional technology) Conventionally, microlenses or microlens arrays have been produced using a special glass substrate using an ion exchange method. However, this method requires a considerable amount of time to manufacture, and the aperture of the lens The disadvantage is that the number (N, A, ') cannot be made very large.Also, microlenses and microlens arrays can be fabricated by plastic molding methods, cellulose embedding methods, etc., but the former suffers from light loss. , high NΔ, reliability, etc. The latter has problems such as assembly method and monolithic integration on the same substrate.

(d+ Purpose of the Invention In view of the above-mentioned drawbacks of the conventional art, an object of the present invention is to provide a method for manufacturing an embedded flat microlens that can efficiently couple a large number of optical lenses with other optical devices. It is something to do.

te) Structure of the Invention In order to achieve the above-mentioned object, the present invention is achieved by locally heating a substrate with a laser beam and thermally diffusing a substance that increases the refractive index, such as germanium, into the heated portion. .

Embodiments of the Invention Hereinafter, embodiments of the method for manufacturing an embedded flat microlens according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view (al is a quartz plate heated with a laser beam) for explaining an embodiment of the method for manufacturing an embedded flat plate microlens according to the present invention.

tbl is a cross-sectional view of a microlens array formed on quartz, where 1 is a laser beam, 2 is a refractive index increasing material gas, 3 is a quartz substrate, 4 is a temperature distribution, 5 is a refractive index distribution, and 6 is a microlens refractive index distribution , 7 is the refractive index increasing material distribution.

In FIG. 1(a), the surface of the quartz substrate 3 on which the microlens will be formed is made of germanium tetrachloride (GeC1) with a thickness of several tens of mm.
4) The quartz substrate 3 is wrapped in a refractive index increasing substance gas 2 consisting of the like, and the quartz substrate 3 is exposed perpendicularly to the quartz substrate 3 by a TEMoo mode spora 1 to a laser beam 1 whose size and power are controlled. When locally heated to near the melting point of quartz substrate 3, refractive index increasing material gas 2 (GeC
Germanium (Ge) thermally decomposed from 14) is thermally diffused, and a refractive index distribution 5 proportional to the temperature distribution 4 is formed in the quartz substrate 3. FIG. 1 (bl) is an embedded flat microlens array in which the aforementioned embedded flat microlenses are aligned with high accuracy.

2A and 2B are cross-sectional views of a silicon plate heated with a laser beam, and FIG. This is a cross-sectional view showing the formation of a microlens array, in which the same parts as in the previous time are given the same reference numerals, 8 is a silicon substrate, and 9 is a silicon oxide (SiO2) film.

In FIG. 2+a), a silicon oxide film 9 is formed on both sides of a silicon substrate 8, and the surface on which a microlens is to be formed is made of germanium tetrachloride (G) with a thickness of several mm.
The silicon substrate 8 is covered with a refractive index increasing substance gas 2 consisting of eC14), etc., and is perpendicular to the silicon substrate 8 by a laser beam 1 with controlled spot size and power in the T E Mo o mode for a predetermined period of time (several seconds to several minutes). If the substrate 8 is locally heated to near its melting point, germanium (Ge) thermally decomposed from the refractive index increasing material gas 2 (GeC14) will be formed on the surface of the silicon substrate 8 in proportion to the temperature distribution 4 on the surface of the silicon substrate 8. is thermally diffused, and a refractive index distribution 5 proportional to the temperature distribution 4 is formed in the silicon substrate 8.

FIG. 2 (to) shows an embedded flat microlens array in which the above-mentioned embedded flat microlenses are arranged with high precision. If the resist 1IiJIQ is thus formed on the silicon surface (110 surface) on which the microlenses are not formed of the silicon substrate 8 and etched as shown in FIG. 3, there is an advantage that the optical fiber 11 can be easily connected.

[g) Effects of the invention As is clear from the above explanation, according to the method for manufacturing an embedded flat microlens according to the present invention, microlenses and microlens arrays can be formed on a substrate by precisely controlling laser light. Since it can be manufactured easily and accurately, it greatly contributes to improving mass productivity and quality.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a diagram illustrating an embodiment of the method for manufacturing an embedded flat plate microlens according to the present invention (al is a method in which a quartz plate is heated with a laser beam to form a microlens). (b) is a cross-sectional view of a microlens array formed on quartz, and FIG. 2 is a cross-sectional view of (al
For example, FIG. 3 is a cross-sectional view showing a microlens formed by heating a silicon plate with a laser beam. FIG. In the figure, 1 is a laser beam, 2 is a refractive index increasing material gas, 3 is a quartz substrate, 4 is a temperature distribution, 5 is a refractive index distribution, and 6
1 is a microlens refractive index distribution, 7 is a refractive index increasing material distribution, 8 is a silicon substrate, 9 is a silicon oxide (SiO2) film, and 10 is a resist film. 11 indicates an optical fiber. Procedure: (Method) B passed away February 14, 1960 1. Indication of the incident 1982 Patent Application No. 163915 2. Name of the invention Method for manufacturing an embedded flat microlens 3. Making corrections Relationship with the case Patent applicant address 1015 Kamiodanaka, Nakahara-ku, Yozaki City, Kanagawa Prefecture (5
22) Name: Fujitsu Co., Ltd. - Fujitsu Co., Ltd. 5 Date of amendment order: January 29, 1985 (shipment date) [The figure is] corrected to read, ``Figure, (b) is a cross-sectional view of a microlens array formed on silicon, and Figure 3 is''. Below l-

Claims (2)

[Claims] (1) A method for manufacturing an embedded flat microlens, comprising the steps of locally heating a substrate with a laser beam and thermally diffusing a substance that increases the refractive index into the heated portion. (2) The method for manufacturing an embedded flat microlens according to claim 1, wherein the heating by the laser beam is performed in a refractive index increasing material gas.