WO1998045740A1

WO1998045740A1 - Device for connecting optical elements and method for producing the same

Info

Publication number: WO1998045740A1
Application number: PCT/CH1998/000090
Authority: WO
Inventors: Helmut Schift; Jürgen Soechtig
Original assignee: Paul Scherrer Institut
Priority date: 1997-04-08
Filing date: 1998-03-05
Publication date: 1998-10-15

Abstract

The invention relates first of all to a device for connecting optical elements on a support unit (TE). At least one insertion element (EE) which can be inserted into said support unit (TE) is provided. The support unit (TE) has at least one positioning element and the insertion element (s) (EE) has/have a counterpart (GS) corresponding to each of the positioning elements of the support unit. Since the insertion elements (EE) also have optical elements (OE), the inventive device is particularly suitable for mass-producing optical units. The invention also relates to a production method for producing the insertion elements (EE) simply and economically, based on LIGA (lithography, electroforming, molding) technology.

Description

Device for connecting optical elements and method for producing the same

The present invention relates to a device according to the preamble of claim 1, the use thereof and a manufacturing method.

The mutual alignment of optical elements such as glass fibers, lenses, detectors and light sources is one of the main tasks in the manufacture of micro-optical units.

Various approaches are known for the coupling of optical emission from lasers in glass fibers, which differ in terms of flexibility, coupling efficiency and adjustment effort. A known and frequently used coupling is that a glass fiber is butt-coupled with a laser and then cast with transparent polymer. A resulting connection requires precise alignment of the elements involved with respect to several axes and is fixed with polymer after casting and can therefore no longer be changed. It is no longer possible to adapt the beam characteristic or multiply the beam by optical elements. Although optical elements can be inserted into a space between the laser and the fiber, precise alignment must also be carried out here.

The present invention is therefore based on the object of specifying a device which does not have the disadvantages mentioned above. This object is achieved by the measures specified in the characterizing part of patent claim 1. Advantageous embodiments of the invention, a use and a manufacturing method are specified in further claims.

Connecting elements that can be used for optical elements and that combine both positioning and optical functions offer significant advantages in terms of flexibility and in terms of the mutual alignment effort. The device according to the invention is also particularly characterized by a repeatable alignment of the elements to be connected.

For its part, the manufacturing method according to the invention has the particular advantage that, once polymer replication techniques have been used, alignments that have been set can be easily reproduced.

The invention is explained in more detail below with reference to drawings, for example. Show

Fig. 1 shows the device according to the invention in perspective view

Fig. 2 molded parts that are used for the production of insert elements according to the invention.

1 shows a device according to the invention, consisting of a carrier unit TE with one inserted therein Fiber F and an insert element EE with an optical element OE, shown. Furthermore, an optical unit OET, for example a laser diode, can be seen on the carrier unit TE.

The device according to the invention is shown twice in FIG. 1: The left part of FIG. 1 shows a device according to the invention in which the insert element EE is not inserted into the carrier unit TE, while on the right side of FIG

Insert elements EE provided support unit TE is shown. Last but not least, it is intended to clarify that the insert element EE and thus the optical element OE present on this are interchangeable.

1 is a coupling of optical emission from a laser as an optical unit OET into a fiber F, for example into a glass fiber, the fiber F being aligned in the desired orientation by a fixing groove FN present in the carrier unit TE becomes. A recess AN is provided transversely to an optical axis defined by the fiber F and receives the insert element EE. The aforementioned optical unit OET is provided on the carrier unit TE, which also lies on the optical axis defined by the fiber F, but is located on the other side of the recess AN with respect to the fiber F.

The insert element EE provided with the optical element OE is used to focus the light emitted by the optical unit OET on the end face of the fiber F; designed recess AN can be optimally positioned accordingly.

In Fig. 1 are positioning elements and corresponding counterparts that are used for the mutual alignment of

Insert element EE and carrier unit TE are required, not shown. Such positioning elements or their counterparts consist, for example, of pins and grooves which engage one another and are used, for example, with the aid of an etching technique and / or with

Wire EDM technology manufactured. For example, metallic pins are produced on the one hand, preferably with the aid of the wire terion technology and grooves on the other hand with the aid of an etching technique. Pins or inserted cylindrical pins or cylindrical rods can also be inserted glass fibers.

First, however, reference should be made to further design variants of the device according to the invention:

Thus, in a further development of the teaching according to the invention, several insert elements EE are placed in the recess AN, both optical elements OE and optical units OET being provided on the individual insert elements EE in the sense of the terminology used in this document. In the case of implementation forms in which distances between the individual insert elements EE are to be maintained, spacers should preferably be provided between the insert elements EE or to the side walls of the recess AN.

To further fix the insert elements EE in the carrier unit TE - be it for realizing the The device according to the invention with one or be it for an implementation with several insert elements EE - the use of elastic elements, for example spring elements, has proven to be particularly advantageous.

The optical banks mentioned allow a number of so-called optical functions, which can in particular be the following:

Mapping functions: Mapping fiber / laser / detector to fiber / laser / detector;

and or

Collimation functions;

and or

- Beam shaping functions: e.g. B. Absorption in

Polymer or polymer dye additions;

and or

- Distribution and linking functions: from one fiber to several other fibers; from one fiber to a special other, not opposite fiber;

and or

Modulation functions: through z. B. electrical actuator membranes or electrical or thermally controllable resonators designed by non-linear optical polymers;

and or

polarization changing functions: linear, circular polarizers by z. B. stretched polymer films;

and or

Blocking functions: for example optical apertures, blackening.

Finally, it should be noted that a

Carrier unit TE can accommodate several fibers F and thus also several corresponding optical units OET or elements OE. In such applications it is often referred to as so-called optical banks, which are particularly useful for plug connections, e.g. Fiber connectors are used.

2 shows molded parts for the production of insert elements EE, a base plate BP, an intermediate plate ZP and a cover plate DP being provided. The base plate BP has surface structures OS on the side facing the intermediate plate ZP, which are used to produce optical elements OE in the insert elements EE. The intermediate plate ZP preferably has the same thickness as the insert element EE to be produced and is laterally provided with the negative of further desired structures, for example positioning elements PE. Finally points the cover plate DP inlet holes EL through which an optically transparent plastic (for example PMMA or PC or polystyrene or polydiacetylene or BCB (benzocyclobutane) or polyurethane or transparent silicone elastomers or polysilane or polysiloxane or

Polyimide or visible or UV or thermally curing epoxy or polyimide adhesives) is filled.

The molded parts shown in FIG. 2, in particular the intermediate plate ZP, are preferably produced using the known so-called LIGA (lithography, electroforming, molding) technology, which was developed by W. Menz and P. Bley in "Microsystem Technology for Engineers" (VCH Verlag Weinheim, 1993) or by W. Ehrfeld et. al. in "Deep x-ray lithography for the production of three-dimensional microstructures from metals, polymers and ceramics" (Radiat. Phys. Che. Vol. 45, No. 3, pages 349 to 365, 1995).

In fact, other lithographic ones can be

Use the BP, ZP and DP molding process. A number of other methods are suitable for producing the molded parts, including in particular for producing the base plate BP, which has integrated optical functions:

The first is the so-called diamond NC turning as a possibility of very fine mechanical

Manufacturing technology, electroforming and replication (J. Futhey and M. Flemming, "Superzone diffractive lenses", OSA Technical Digest Series: Diffractive Optics: Design, Fabrication and Applications, Vol. 9, pages 4 to 6, Washington, DC: OSA, 1992). Another manufacturing process is an optical photolithography process that uses multi-stage contact exposure and subsequent electroplating and replication. In this regard, reference is made to the article by MR Feldmann entitled "Diffractive optics move into the commercial arena" (Laser Focus World, pages 143 to 152, 1994).

Laser writing is also an option for optical photolithography, electroforming and replication. In this regard, the article by M. T. Gale et. al. with the title "Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresist" (Optical Engineering, Nov. 1994, Vol. 33, No. 11, pages 3556 to 3566).

The molded parts can also be produced by means of direct electron beam writing. Regarding the process, reference is made to the article by Parriaux with the title "E-beam machines write smooth optical curves" (Opto & Laser Europe, Issue 27, pages 26 to 28, March 1996).

Finally, optical and / or electron-optical lithography with subsequent dry etching can also be used

Manufacture of molded parts can be used. In this regard, the article by M. Eisner et. al. with the title "Tranferring resist microlenses into Silicon by reactive ion etching" (Optical Engineering, Vol. 35, pages 2979 to 2982, 1996).

The production processes mentioned above can also be used to produce the cover plate DP deploy. In addition, other fine or ultra-fine mechanical methods and / or wire erosion techniques can be used to produce ventilation nozzles or filling channels.

Any number of insert elements EE can now be produced with the molded parts, the required positioning elements PE and the optical elements OE, which can convey the optical functions mentioned, being produced simultaneously in the same operation.

Claims

Claims:

1. Device for connecting optical elements on a carrier unit (TE), characterized in that at least one insert element (EE) in the carrier unit

(TE) can be used, the carrier unit (TE) having at least one positioning element (PE) and the insert element (s) (EE) corresponding to each of the positioning elements (PE) of the carrier unit (TE)

(GS), and that the insert element (s) has or have at least one optical element (OE).

2. Device according to claim 1, characterized in that the carrier unit (TE) has a recess (AN) for receiving at least one insert element (EE).

3. Device according to claim 1 or 2, characterized in that the positioning elements (PE) and / or their corresponding counterparts (GS) consist of grooves and / or pins.

4. Apparatus according to claim 2 or 3, characterized in that a plurality of insert elements (EE) can be inserted into the recess (AN), the individual insert elements (EE) being spaced apart from one another by a spacer.

5. Device according to one of claims 2 to 4, characterized in that elastic elements are provided which hold the insert elements (EE) in a predetermined position. β. Device according to one of the preceding claims, characterized in that an optical unit (OET), in particular a light source or a detector, is placed on an insert element (EE).

7. Use of the device according to one of claims 1 to 6 in an optical bench, on which optical functions are preferably imparted.

8. A process for the production of insert elements (EE) for optical units, the process consisting in

that individual or all molded parts (BP, ZP, DP) are produced by means of lithographic processes, the intermediate plate preferably using LIGA technology, the moldings containing both means (PE, GS) for alignment and means (OE) for performing optical Functions are generated, and

that the insert elements (EE) are manufactured using injection molding technology or hot forming or casting technology - preferably with optical, UV or thermally curing epoxy adhesives.

9. The method according to claim 8, characterized in that an optically transparent polymer, preferably PMMA or PC or polystyrene or polydiacetylene or benzocyclobutane or polyurethane or transparent silicone elastomers or polysilane or polysiloxane or polyimide or visible or UV or thermally curing Epoxy or polyimide adhesives, used to manufacture the insert elements (EE).