Ex Parte Dowd et al

Board of Patent Appeals and Interferences

Aug 8, 2012

11364122 (B.P.A.I. Aug. 8, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/364,122 02/28/2006 Edward M. Dowd WEAT/0648 8418
36735 7590 08/08/2012
PATTERSON & SHERIDAN, L.L.P.
3040 POST OAK BOULEVARD, SUITE 1500
HOUSTON, TX 77056
EXAMINER
DEHGHAN, QUEENIE S
ART UNIT PAPER NUMBER
1741
MAIL DATE DELIVERY MODE
08/08/2012 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte EDWARD M. DOWD and
PAUL E. SANDERS
____________

Appeal 2011-008703
Application 11/364,122
Technology Center 1700
____________

Before BRADLEY R. GARRIS, TERRY J. OWENS, and
BEVERLY A. FRANKLIN, Administrative Patent Judges.

GARRIS, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2011-008703
Application 11/364,122

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Appellants appeal under 35 U.S.C. § 134 from the Examiner's
rejection under 35 U.S.C. § 103(a) of claims 1, 3, 6, 7, and 9-14 as
unpatentable over Brehm (US 4,978,377 issued Dec. 18, 1990) in view of
Berkey (US 4,561,871 issued Dec. 31, 1985). We have jurisdiction under
35 U.S.C. § 6.
We REVERSE.

Appellants claim a method for fabricating an optical fiber preform 250
comprising: assembling pre-shaped sections of glass materials 222, 232
surrounding an inner rod 210 having a core 202 and cladding 204, wherein
at least two of the pre-shaped sections 222 are placed diametrically opposite
to one another and are made from a material having a relatively higher
coefficient of thermal expansion than the other pre-shaped sections 232,
wherein the at least two pre-shaped sections 222 comprise doped silica-
based glass with ratios of the dopants selected to produce a refractive index
of the silica-based glass matched to a refractive index of the cladding (claim
1; Fig. 2).
Representative claim 1, the sole independent claim on appeal, reads as
follows:
1. A method for fabricating an optical fiber preform,
comprising:
assembling pre-shaped sections of glass materials
surrounding an inner rod having a core and cladding, wherein at
least two of the pre-shaped sections, placed diametrically
opposed to one another, are made from a material having a
relatively higher coefficient of thermal expansion than the other
pre-shaped sections, wherein the at least two of the pre-shaped
sections comprise doped silica-based glass, wherein the doped
silica-based glass comprises at least two dopants, and wherein
Appeal 2011-008703
Application 11/364,122

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ratios of the dopants are selected to produce a refractive index
of the silica-based glass matched to a refractive index of the
cladding; and
surrounding the pre-shaped sections by a glass tube.
In rejecting sole independent claim 1, the Examiner finds that Brehm
discloses an optical fiber preform having pre-shaped sections surrounding an
inner rod having a cladding but acknowledges that "Brehm does not
specifically teach matching the refractive index of the pre-shaped section[s]
to the refractive index of the cladding [as required by claim 1], although
[such index matching is] suggested by the avoidance of parasitic light
guiding effects" (Ans. para. bridging 4-5). Concerning this deficiency, the
Examiner finds that Berkey discloses a similar preform having pre-shaped
sections with dopants selected to produce a refractive index to match the
cladding refractive index (id.). The Examiner concludes that, in view of
Berkey, it would have been obvious "to have similarly matched the index of
refraction of the pre-shaped sections of Brehm to the cladding [refractive
index]" (id.).
As correctly indicated by Appellants, the pre-shaped sections of claim
1 and of Brehm surround the inner rod cladding whereas Berkey's pre-
shaped sections (i.e., stress rods 60; see, e.g., Fig. 6) are contained within the
inner rod cladding (i.e., cladding 56 of core 54; see, e.g., Fig. 6) (Br. 12).
Appellants argue that Berkey's "[pre-shaped] sections internal to the
cladding do not teach or even suggest pre-shaped sections, surrounding the
cladding, which have a refractive index matched to a refractive index of the
cladding as required by claim 1" (id.) and that "[t]herefore, Berkey fails to
overcome the deficiencies in Brehm (id.).
Appeal 2011-008703
Application 11/364,122

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In response, the Examiner emphasizes that both Brehm and Berkey
utilize stress elements (i.e., pre-shaped sections) which eventually fuse with
the cladding to induce birefringence (Ans. 7-9). However, the Examiner has
not explained why this fact would have suggested matching the refractive
indices of Brehm's pre-shaped sections and cladding.
The Examiner further responds by stating that "[t]he stress elements
of Berkey also surrounds [sic] a portion of the cladding of the preform, as
indicated by the cladding portion between the core and stress elements in
figures 6, 8-9, and 11" (id. at 8). This statement is incorrect. While these
figures show a cladding portion between the core and stress elements (see,
e.g., cladding portion 56 between core 54 and stress elements 60 in Fig. 6),
this cladding portion is adjacent to, not surrounded by, the stress elements.
Additionally, the Examiner contends that the proposed combination of
Brehm and Berkey would have been motivated by Brehm's teaching in
column 3, lines 11-28, of using dopant (i.e., fluorine) to alter refractive index
and thereby avoid parasitic light guiding effects (Ans. para. bridging 9-10).
As clarification, this teaching relates to the use of fluorine dopant in the pre-
shaped sections of Brehm which have a relatively low coefficient of thermal
expansion (CTE) (col. 3, ll. 11-28; col. 4, ll. 25-31) whereas claim 1 uses
index-changing dopants in the pre-shaped sections having a relatively high
CTE. The Examiner fails to explain how Brehm's above teaching directed to
doping low CTE sections would have motivated an artisan to provide high
CTE sections with dopants selected to produce a refractive index matched to
the cladding refractive index as required by claim 1.
The circumstances recounted above lead us to determine that
Appellants' argument is persuasive. On its face, the argument is rational and
Appeal 2011-008703
Application 11/364,122

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has merit. On the other hand, the Examiner has failed to provide this record
with a rebuttal which reveals the argument to be ultimately unconvincing.

For these reasons, we cannot sustain the Examiner's § 103 rejection of
the appealed claims.

The decision of the Examiner is reversed.

REVERSED

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