JPH0615114B2 - Optical component fixing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Laser light is used to melt and solidify glass, which is an optical component of an optical device, and also metal 15 of a mechanical component is also solidified to fix the metal and the glass. It meets the various performances required for fixing optical components and various requirements for fixing method.

[Industrial application field]

The present invention relates to a method for fixing an optical component, and more specifically to a method for fixing glass, which is an optical component of an optical device, and metal, which is a mechanical component.

The following requirements are imposed on the fixing portion between the glass, which is the optical component of the optical device, and the metal, which is the mechanical component, and the method for forming the same.

(A) The number of man-hours for fixing is small and the time is short. (B) The fixing part is sufficiently stable against heat applied to the fixing part and a heat cycle during the use of the optical device.
If the fixing is loosened or the fixing portion is distorted during the use of the optical device, there is a problem in that the optical components such as the lens are displaced and the optical path is displaced. Therefore, from the viewpoint of reliability, it is required that the fixing portion be sufficiently stable over time during use of the optical device.

(C) The stress applied to the optical parts by fixing is small. In an optical device that uses polarized waves, stress applied to a lens or the like causes a birefringence phenomenon, which makes the characteristics of the optical device unstable. Therefore, an optical device that uses polarized waves requires a fixing method that generates as little stress as possible.

(D) The time for heating the optical parts when fixing is short. When fixing is performed by a thermal method, not only the fixing part of the optical component but also the whole is affected by heat. For example, the application of heat to a lens coated with a non-reflective coating can degrade the coating. Therefore, in such a case, it is necessary to finish the fixing in a short time and shorten the heating time of the optical component.

[Conventional technology]

As conventional fixing methods, (a) press-fitting method, (b) adhesive method using an adhesive such as resin, and (c) soldering joining method are known. The press-fitting method (a) is extremely unsatisfactory with respect to the requirement (c) above. That is, in the press-fitting method, since a lens or the like is inserted into a metal tube and fixed by the pressure between the two, high pressure is applied to the lens or the like, so that an undesired phenomenon such as birefringence is unavoidable. Next, the adhesion method (b) is insufficient for the requirement (a) above because the time for curing the resin is long. In addition, since the adhesive portion of the resin has insufficient heat resistance, the adhesive method (b) is also insufficient for the requirement (b). Further, in the solder joining method of (c), glass solder is used and molten solder is used for joining by utilizing ultrasonic waves. Since this method heats the entire fixed part, there is a loss time, so it is insufficient for the requirement of (a), and when the fixed part is heated to a temperature of several hundreds of degrees, the entire lens also reaches a considerable temperature. Therefore, it is insufficient for the request of (d).

[Problems to be solved by the invention]

The present invention provides a fixing method which satisfies the above (a)-(d) at a high level.

[Means for solving problems]

That is, the present invention arranges a glass member, which is an optical component of an optical device, and a metal member, which is a mechanical component, adjacent to each other, and irradiates a laser beam from the metal member side to the glass member side at the adjacent portion. An optical component for fixing the glass member and the metal member by melting and solidifying from the metal member to the surface layer portion of the glass member and directly joining the melt and solidified portion of the metal member and the melt and solidified portion of the glass member. It is a fixing method of.

FIG. 1 is a principle diagram of the present invention. As shown in the figure, when the glass 100, which is an optical component, is fixed to the metallic mechanical component 101, laser light is emitted from the mechanical component 101 side. And
Up to the glass 100, it is melted and solidified.

[Work]

In the present invention, the laser light is emitted from the metal side in order to form the molten portion of the metal and to fix the molten and solidified portion formed by solidifying the molten portion. It is also for keeping the amount of heat applied to the glass as small as possible. In the examples of the present invention to be described later, it is understood that a considerable amount of heat is input to the metal because the holes formed by the laser light are formed in the laser light irradiation metal part, but the amount of heat applied to the entire glass is significantly Not many, but limited to the required limit and localized heating. Further, in the present invention, the laser beam is used because the laser beam can irradiate a work with a large amount of energy in a short time as compared with other energy irradiating means, and the refractory glass is melted from the metal side. This is because it is a possible energy means. Further, the reason why the glass surface is melted and solidified in the present invention is to fix both of them by utilizing melting of glass in addition to melting of metal.

According to the present invention, since the object to be fixed is directly heated and fixing is completed by laser irradiation for a short time, the requirements of (a) and (d) are satisfied, and the molten solidified glass and the metal are used for fixing. Since the fixed part has excellent heat aging characteristics,
A fixing method is provided in which the fixing portion does not deteriorate with time (satisfies the requirement of (b)) and has less stress (satisfies the requirement of (c)).

〔Example〕

Examples of the metal that can be fixed in the present invention include Kovar, stainless steel, copper, N52, etc., and are selected in consideration of the matching of the expansion coefficient with glass and the melting property. . Also,
If the metal mechanical component is too thick, a very high power laser source must be used, making the method less practical. Therefore, the practical upper limit of metal mechanical parts is about 1 mm.
It is a degree.

Laser energy is 3 to 30 J, preferably 8 to 12 J
A pulsed laser of msec is commonly used. When such a laser is used for fixing, a glass which is generally difficult to melt is melted to the extent necessary for fixing because a high temperature part is formed instantaneously and locally. Very desirable results are obtained in this method because heat transfer is blocked.

Hereinafter, the present invention will be described with reference to the drawings.

2A and 2B show a part of an optical device in which light emitted from a fiber (not shown) is converted into a parallel beam by the lens 1, and the light of a device such as a filter or a prism is processed by the function of the device. Then enter another lens (not shown),
The part that enters the fiber (not shown) again is shown. Reference numeral 2 is a holder for fixing the lens 1. Reference numeral 3 denotes a fixing portion for fixing the lens 1 to the holder 2.

FIG. 3 shows details of the fixing portion 3. Laser light is irradiated from the holder 2 side to melt the metal of the holder 2 as indicated by the arrow. If the energy of the laser light is high, the same figure
When the molten metal partially evaporates and a hole 4 is made in the wall surface of the holder 2 as in (a), and the energy of the laser beam is low,
The evaporation of the molten metal does not occur so conspicuously as in (b), and the hole 4 is not formed. The glass is also locally melted on the outer peripheral surface of the lens 1 by the heat of the molten metal. Holder 2 as described above
And the glass of the lens 1 are melted, and after the irradiation of the laser light is stopped, the molten portion of the metal of the holder 2 and the glass of the lens 1 is solidified (solidified). As a result, the metal and glass directly contact and solidify. In the figure, the solidified portions of the metal formed near the outer peripheral surface of the glass 1 are indicated by 5 and 5 ', and the solidified portion of the glass is indicated by 6. A fusion solidification portion of metal and glass may exist between these solidification portions 5 and 6 with a slight thickness, but it is not shown. The metal and glass are directly bonded along the inner surface of the (evaporation) hole 4 or at the melting surface by the solidifying portions 5 and 6 as described above. 8 is a gap which exists between the lenses 1 and 2 and which allows the insertion of the lens 1, and is usually 0.1 mm or less. Since the depth of glass melting is generally very small with respect to the diameter of the lens 1, it does not interfere with the parallel beam passing through the lens 1 at all.

A sufficient fixing effect can be obtained by fixing the lens 1 and the pipe at several points on the circumference of the lens 1 as shown in FIG.

According to the method of the present invention, the metal of the holder 2 is melted and evaporated, the glass of the lens 1 is melted and evaporated, and the workpieces 1, 2 during the solidification portions 5, 6 are formed.
Especially, the temperature of the central portion of the lens 1 hardly rises. Therefore, there is almost no thermal strain generated in the workpieces 1 and 2. Further, since the time for forming one fixed portion 4 is at most a unit of seconds including the time for aligning the laser energy source with the irradiated portion, the working time by this method is extremely short. In addition, in the fixing portion 3, the metal and the glass are directly fixed (including the case where they are fused), and there is no fixed matter interposed between the metal and the glass. Therefore, as compared with the case where there is an intervening adhered matter such as solder or resin, the positional reliability of the lens 1 does not occur during the use of the optical device, and the fixing reliability is improved.

Since the method has various advantages as described above, excellent reliability can be obtained when the method is applied to fixing where birefringence becomes a problem particularly in an optical device using polarization.

Although the embodiment of the lens has been described in the above description, the present method can also be used when fixing an optical component such as a prism to a substrate-like mechanical component.

An example of an experiment conducted by the present inventor will be described below.

Put a lens (BK7) with a diameter of 4.5 mm into a lens holder with a wall thickness of 0.5 mm, and irradiate from the lens holder with YAG laser (10 msec pulse laser) with an energy of about 12 J. The lens was fixed to the lens holder in place. When the lens was pushed with a rod and the fixing force was measured by using the force when the lens was disengaged from the lens holder, a fixing result of 4 kg was obtained.

Also, the energy per area can be changed by shifting the focal position of the laser light 7 as shown in FIG. 3 (c). By adjusting the energy and the focus depending on the thickness of the lens holder, the strongest fixing force can be obtained. Is obtained.

〔The invention's effect〕

As described above, according to the present invention, since the requirements (a)-(d) imposed on the method of fixing the optical component and the mechanical component are satisfied at a high level, the present method has been rapidly developing in recent years. It greatly contributes to the further improvement of device technology.

[Brief description of drawings]

1 is a principle view of the present invention, FIG. 2 (a) is a front view of a lens holder, and FIG. 2 (b) is a sectional view taken along line (b)-(b) of FIG. 1 (a). , (A)-(b) of FIG. 3 are enlarged views of the fixing part of FIGS. 1 (a) and (b), and FIG. 3 (c) is a view showing the fixing part of FIG. 2 (b) separately. 3 is an explanatory diagram of an example of FIG. 1 ... Lens, 2 ... Holder, 3 ... Fixed part, 5 ... Solidified metal part, 6 ... Solidified glass part.

Claims (1)

[Claims] 1. A glass member (1) which is an optical component of an optical device.
00) and a metal member (101) which is a mechanical component are arranged adjacent to each other, and at the adjacent portion, a laser beam (103) is irradiated from the metal member side toward the glass member side, and the metal member described above is irradiated. The glass member (100) and the metal member are melt-solidified up to the surface layer of the glass member, and the glass member (100) and the metal member are directly joined by the melt-solidified part (5) of the metal member and the melt-solidified part (6) of the glass member.
(101) A method of fixing optical components for fixing and.