Optical reflection modulator
First Claim
1. A reflection modulator (11) for a light beam emerging from an optical fiber (42) and re-entering the same, comprising:
- a modulator unit based upon a Fabry and Perot interferometer and having two parallel reflecting layers (18,
20) one of which is mechanically displaceable by a wanted electric signal (NS), and a mechanical mounting which joins the optical fiber (42) and the modulator unit,wherein a base block (14) is provided having two main surfaces (15,
16), andwherein a first one (18) of said reflecting layers (18,
20) is positioned stationary on one (15) of said main surfaces (15,
16) and a second one (20) of said reflecting layers (18,
20) is arranged essentially parallel to said first one (18) of said reflecting layers and separated by an air gap (19).
1 Assignment
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Accused Products
Abstract
The reflection modulator (11), serving the purpose of modulating a light beam emerging from an optical fiber (42) and re-entering the same, is essentially based on a microstructural Fabry and Perot interferometer. The interferometer is formed by two parallel reflecting layers (18, 20) which are electrically conductive, electrically insulated from each other, and connected to electric terminals (28, 30), and an air gap (19) which is comprised between them. A mechanical excursion of one (20) of the two reflecting layers can thus be produced by an electric wanted signal (NS). The reflecting layers (18, 20) are disposed on a base block (14) of monocrystalline silicon having two parallel main surfaces (15, 16) each of which is covered by two passivating coatings (25, 35, 26, 36). The base block (14) is provided with a recess on one (16) of the main surfaces. An optical fiber (42) is fastened in said recess by means of an adhesive (44) in such a manner that the fiber end is completely enclosed by said adhesive. Thereby and by the structure of the associated coatings (26, 36), a minimal reflection is obtained. On the other main surface (15), the combination of the corresponding coatings (25, 35) and of the fixed reflecting layer (18) result in semipermeability to the light beam emerging from the optical fiber (42) and passing through the base block (14). After its modulation in the Fabry and Perot interferometer, the light beam returns to the optical fiber (42) in the reverse direction. (FIG. 1).
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Citations
20 Claims
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1. A reflection modulator (11) for a light beam emerging from an optical fiber (42) and re-entering the same, comprising:
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a modulator unit based upon a Fabry and Perot interferometer and having two parallel reflecting layers (18,
20) one of which is mechanically displaceable by a wanted electric signal (NS), and a mechanical mounting which joins the optical fiber (42) and the modulator unit,wherein a base block (14) is provided having two main surfaces (15,
16), andwherein a first one (18) of said reflecting layers (18,
20) is positioned stationary on one (15) of said main surfaces (15,
16) and a second one (20) of said reflecting layers (18,
20) is arranged essentially parallel to said first one (18) of said reflecting layers and separated by an air gap (19). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for the manufacture of a reflection modulator (11) for a light beam emerging from an optical fiber (42) and re-entering the same, said reflection modulator (11) comprising a base block (14) initially forming a part of a silicon wafer, said method comprising:
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first, altering said silicon wafer by evaporating and etching procedures in such manner as to form on said base block (14) two reflecting layers (18,
20) with an air gap (19) between them, a recess (40), coasting 25, 26, 35,
36) and at least one supporting element (51,
56);second, affixing a cover member (50) to said at least one supporting element (51,
56) on said base block (14) for mechanically protecting at least said two reflecting layers (18,
20) and said air gap; andthird, subsequently detaching said base block (14) from said silicon wafer.
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Specification