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Lensless Fiber Stub Hermetically Sealed Optoelectronic Package

IP.com Disclosure Number: IPCOM000111481D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 4 page(s) / 135K

Publishing Venue

IBM

Related People

Schott, FJ: AUTHOR

Abstract

This article describes a new and unique design and procedure for building an optoelectronic package for high performance optoelectronic communications equipment (or other similar equipment uses). This design has 4 main advantages over the current state-of-the-art (or industry practice). One, the fiber stub-ferrule element is both a lens and a very accurate optical alignment mechanical fixture. Two, the fiber stub-ferrule can be metalized and metallurgically sealed to the package housing, thereby forming a hermetic seal. Third, this fiber stub/hermetic design capable of more efficiently coupling light into a fiber-optical cable and requires fewer components.

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Lensless Fiber Stub Hermetically Sealed Optoelectronic Package

      This article describes a new and unique design and procedure
for building an optoelectronic package for high performance
optoelectronic communications equipment (or other similar equipment
uses).  This design has 4 main advantages over the current
state-of-the-art (or industry practice).  One, the fiber stub-ferrule
element is both a lens and a very accurate optical alignment
mechanical fixture.  Two, the fiber stub-ferrule can be metalized and
metallurgically sealed to the package housing, thereby forming a
hermetic seal.  Third, this fiber stub/hermetic design capable of
more efficiently coupling light into a fiber-optical cable and
requires fewer components.  Fourth, as a result of the fewer
components, easier alignment and higher efficiency coupling of energy
(light), this package is significantly cheaper and has higher
reliability.

      The fiber stub acts as a lens to efficiently couple the optical
energy (light) from the optical source into a fiber-optical
cable/connector, thereby eliminating the need for a separate lens and
other mechanical beam alignment sub-componentry.  Alignment of these
separate sub-components to the 0.5 micron accuracy required is very
costly, time consuming and requires very expensive capital equipment.

      The unique "fiber stub" technique provides for a more efficient
Laser-to-Optical fiber coupling and alignment accuracy.  This allows
maximum optical power to be coupled from the optical source
(Semiconductor Laser diode, LED or other similar device) into the
optical fiber while maintaining safety levels dictated by the United
States Food and Drug Administration CDRH and the World Trade IEC 825
Laser Safety Compliance Standards limits.

      An added advantage of this design/process is the metalized
coating of the ferrule and fiber which guarantees very precise
alignment and a hermetic package seal to insure that the
environmental elements cannot ingress into the package and corrode
the sensitive internal sensitive componentry (i.e., the semiconductor
Laser diode or GaAs integrated circuit chips which typically are used
with these type of devices).  The industry practice today is to
incorporate separate hermetic sub-packages for optical devices such
as Laser diode and photo detector I.C.  chips within and overall
optoelectronics package.

      The design and procedures for building this unique
optoelectronic package are described below.

      A 2.5mm diameter ferrule (the preferred ferrule material is
Zirconia ceramic but other materials such as Alumina ceramic, steel
or plastics can be used) with a 9/125 micron singlemode (a 50/125 or
62.5/125 micron multimode fiber could also be used) are metalized on
their respective outer diameters by plating, sputtering or
evaporation techniques.  These metalized surfaces are then coated
with solder so, when heated to melting temperature, will form a high
surfa...