Optical wavelength division multiplexer/demultiplexer having preformed passively aligned optics

• US 6,201,908 B1
• Filed: 07/02/1999
• Issued: 03/13/2001
• Est. Priority Date: 07/02/1999
• Status: Expired due to Term

• Current Assignee: Omron Management Center of America (Omron Corporation)
• Original Assignee: Blaze Network Products, Inc. (Omron Corporation)
• Inventors: Grann, Eric B.
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): CONNELLY, MICHELLE R
• Application Number:
  US09/347,490
• Time in Patent Office: 620 Days
• Field of Search: 385/14, 385/15, 385/24, 385/34, 385/33, 385/39, 385/47, 385/51, 385/52, 359/115, 359/124-127, 359/131, 359/137
• US Class Current: 385/24
• CPC Class Codes: G02B 6/29358 Multiple beam interferometer external to a light guide, e.g. Fabry-Pérot, etalon, VIPA plate, OTDL plate, continuous interferometer, parallel plate resonator G02B6/29347, G02B6/29349, G02B6/2935, G02B6/29361 take precedence; resonator evanescently coupled to light guide G02B6/29335
• CPC Class Codes: G02B 6/29367 Zigzag path within a transparent optical block, e.g. filter deposited on an etalon, glass plate, wedge acting as a stable spacer
• CPC Class Codes: G02B 6/2938 for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
• CPC Class Codes: G02B 6/3865 fabricated by using moulding techniques shaping techniques of plastic materials in general B29C; producing plastic optical fiber connectors B29D11/0075
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4246 Bidirectionally operating package structures
• CPC Class Codes: G02B 6/4292 the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 2201/10121 Optical component, e.g. opto-electronic component
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits
• CPC Class Codes: Y10S 439/931 Conductive coating

Abstract

An optical wavelength division multiplexer and de-multiplexer for single mode or multi-mode fiber optic communication systems is provided. The device includes in its preferred embodiment a prefabricated optical block having a reflective coating on its flat upper surface and a plurality of n filters carried on its flat lower surface. A molded plastic coupling module has a flat upper surface to which the optical block and filters are adhesively mounted and the coupling module also includes a lower surface having a plurality of n aspheric lenses. In the preferred embodiment, a fiber optic cable receptacle is molded to the coupling module along with a collimating lens and a beam reflector so that, when the components are assembled, the optical pathway is passively aligned and no postfabrication alignment adjusting or tuning is required.

Claims

1. An optical wavelength division multiplexer and demultiplexer for single mode or multi-mode fiber optic communication systems, wherein n channels are transmitted through a single fiber optic cable having n different wavelengths and wherein optical couplings, lenses and alignment of the device are achieved by forming and joining of prefabricated parts to avoid post-fabrication alignment and adjustment of the optical pathway otherwise required, comprising:

an optical block having a flat upper surface and a flat lower surface,

a reflective coating carried by said upper surface of said optical block,

a plurality of n filters carried on said flat lower surface of said optical block, said filters adapted to separately filter said n different wavelengths,

a molded coupling module having a flat upper surface on which said flat lower surface of said optical block is mounted,

said molded coupling module also having a lower surface on which a plurality of n aspheric lens surfaces is carried, wherein each of said n aspheric lenses is optically aligned with each of said n filters,

a fiber optic cable receptacle for receiving the end of said fiber optic cable,

a collimating lens optically aligned with said fiber optic cable receptacle, and

beam reflecting means between said collimating lens and said flat upper surface of said molded coupling module to optically align said collimating lens with said plurality of n filters,

whereby said n channels of light introduced through said fiber optic cable are reflected between said reflective coating on the upper surface of said optical block and said plurality of n filters, and wherein each of n channels passes through one of said filters and through one of said n aspheric lens surfaces.

2. The apparatus of claim 1 wherein said molded coupling module has said n aspheric lens surfaces integrally molded on its lower surface.

3. The apparatus of claim 1 wherein said fiber optic cable receptacle is integrally molded into said molded coupling module.

4. The apparatus of claim 3 wherein said collimating lens is integrally molded into said molded coupling module.

5. The apparatus of claim 1 wherein said plurality of n filters comprises n discrete Fabry-Perot filters.

6. The apparatus of claim 5 wherein said molded coupling module further comprises an alignment channel formed in its upper surface and wherein said n discrete Fabry-Perot filters are adhesively mounted in said alignment channel.

7. The apparatus of claim 6 wherein said molded coupling module further comprises a filter registration surface extending perpendicularly to said alignment channel, said filter registration surface forming a seat against which said plurality of filters is placed.

8. The apparatus of claim 7 further comprising a plurality of relief cuts formed in said upper surface of said molded coupling module, said relief cuts extending transversely to said alignment channel, said relief cuts adapted to receive adhesive.

9. The apparatus of claim 8 further comprising adhesive having an index of refraction compatible with said molded coupling module, said adhesive covering the entire upper surface of said molded coupling module, the entire lower surface of said optical block, the lower surface of said filters, and completely filling said alignment channel and said relief cuts.

10. An optical wavelength division multiplexer and demultiplexer for single mode or multi-mode fiber optic communication systems, wherein n channels are transmitted through a single fiber optic cable having n different wavelengths and wherein optical couplings, lenses and alignment of the device are achieved by joining of two prefabricated parts together to avoid post-fabrication alignment and adjustment of the optical pathway otherwise required, comprising:

an optical block having a flat upper surface and a flat lower surface,

a reflective coating carried by said upper surface of said optical block,

a plurality of n discrete Fabry-Perot filters mounted on said flat lower surface of said optical block, said filters adapted to separately filter said n different wavelengths,

a monolithic molded coupling module having a flat upper surface on which said flat lower surface of said optical block is mounted,

said molded coupling module having a molded fiber optic cable receptacle for receiving the end of said fiber optic cable,

said molded coupling module having an integrally molded collimating lens optically aligned with said fiber optic cable receptacle,

said molded coupling module also having a lower surface on which a plurality of n aspheric lens surfaces is integrally molded, wherein each of said n aspheric lenses is optically aligned with each of said n Fabry-Perot filters, and

said molded coupling module having beam reflecting means formed therein between said collimating lens and said flat upper surface of said molded coupling module to optically align said collimating lens with said plurality of n Fabry-Perot filters,

whereby said n channels of light introduced through said fiber optic cable are reflected between said reflective coating on the upper surface of said molded coupling module and said plurality of n discrete Fabry-Perot filters, and wherein each of n channels passes through one of said filters and through one of said n molded aspheric lens surfaces.

11. The apparatus of claim 10 wherein said molded coupling module further comprises an alignment channel formed in its upper surface and wherein said n discrete Fabry-Perot filters are adhesively mounted in said alignment channel.

12. The apparatus of claim 11 wherein said molded coupling module further comprises a filter registration surface extending perpendicularly to said alignment channel, said filter registration surface forming a seat against which said plurality of filters is placed.

13. The apparatus of claim 11 further comprising a plurality of relief cuts formed in said upper surface of said molded coupling module, said relief cuts extending transversely to said alignment channel, said relief cuts adapted to receive adhesive.

14. The apparatus of claim 13 further comprising adhesive having an index of refraction compatible with said molded coupling module, said adhesive covering the entire upper surface of said molded coupling module, the entire lower surface of said optical block, the lower surface of said filters, and completely filling said alignment channel and said relief cuts.