Ex Parte Clark et al

Board of Patent Appeals and Interferences

Jul 31, 2009

10961639 (B.P.A.I. Jul. 31, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte DAVID JAMES CLARK
and PAUL MARSHALL CHARLES
____________

Appeal 2009-002537
Application 10/961,639
Technology Center 2800
____________

Decided:1 July 31, 2009
____________

Before LINDA M. GAUDETTE, MICHAEL P. COLAIANNI, and
JEFFREY B. ROBERTSON, Administrative Patent Judges.

ROBERTSON, Administrative Patent Judge.

DECISION ON APPEAL

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the Decided Date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).

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Application 10/961,639

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STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1-6 and 8-11.2 (App. Br. 16). We have jurisdiction
pursuant to 35 U.S.C. § 6(b).
We AFFIRM.
THE INVENTION
Appellants describe a semiconductor opto-electronic component
having a waveguide laser section, a Distributed Bragg Reflector device and
an Electro-absorption Modulator. (Spec. 4, ll. 3-6). Claims 1, 5, and 6,
reproduced below, are representative of the subject matter on appeal.
1. A semiconductor opto-electronic component, comprising:

(a) a waveguide laser section for guiding optical radiation
comprising a first waveguide having a first end, the
waveguide laser section being configured to transmit
optical radiation towards the first end;

(b) a Distributed Bragg Reflector (DBR) section for
wavelength-selecting optical radiation received from the
first end of the waveguide laser section, the DBR section
comprising a second waveguide and having second and
third opposing ends, the DBR section having a variable
index of refraction associated therewith, the DBR section
being configured to convey optical radiation received
from the second end towards the third end;

(c) an Electro-absorption Modulator (EAM) section for
modulating optical radiation received from the DBR

2 Claim 7 has been canceled and claims 12-14 have been withdrawn from
consideration. (Appeal Brief filed December 24, 2007, hereinafter “App.
Br.,” 4).
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section, the EAM section comprising a third waveguide
having a fourth end;

wherein the waveguide section, the DBR section and the
EAM section are aligned along a component axis and disposed
atop a common semiconductor substrate, the first waveguide is
butt-coupled to the second waveguide such that the first end
adjoins and is contiguous with the second end, the second
waveguide is butt-coupled to the third waveguide such that the
third end adjoins and is contiguous with the fourth end, the first,
second and third waveguides are configured and aligned to
convey optical radiation therethrough along a longitudinal
direction of the component axis, the waveguide section, the
DBR section and the EAM section are monolithically integrated
on the common semiconductor substrate, the DBR section is
configured to permit the index of refraction thereof to be varied
in accordance with a DBR current provided thereto, and the
EAM section is configured to permit a band absorption edge of
the third waveguide to be shifted in accordance with an EAM
modulating current provided thereto.

5. The semiconductor optoelectronic component of claim 1,
wherein the first waveguide has a first thickness greater than a
second thickness of the third waveguide.

6. The semiconductor optoelectronic component of claim 1,
wherein the second waveguide has a first thickness greater than
a second thickness of the first waveguide or the third
waveguide.

THE REJECTIONS
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Mason WO 01/18919 A1 March 15, 2001
Joyner US 2003/0081878 A1 May 1, 2003

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The Examiner rejected claims 1-4 and 8-11 under 35 U.S.C. § 102(b)
as being anticipated by Mason. The Examiner rejected claims 5 and 6 under
35 U.S.C. § 103(a) as being unpatentable over Mason in view of Joyner.
In rejecting the claims on appeal, the Examiner found that Mason
“does not disclose that the waveguide layer common to all three components
consists of three separate waveguide layers that are butt-coupled together to
form a monolithic layer.” (Examiner’s Answer entered February 26, 2008,
hereinafter “Ans.,” 3). However, the Examiner did not accord this limitation
any patentable weight as being a product by process limitation in a device
claim. (Id.). The Examiner found that Mason “discloses the waveguide
layer is formed in one step and is therefore monolithic.” (Id.).
Regarding claims 5 and 6, the Examiner found that Mason does not
disclose differences in thickness between the sections of the waveguide
layer. (Ans. 5). The Examiner found that Joyner discloses that the
waveguide layer of the waveguide section and the waveguide layer of the
DBR section are thicker than the waveguide layer of the EAM section. (Id.).
The Examiner determined that it would have been obvious to incorporate the
teachings of Joyner into the device of Mason to increase the bandgap of the
EAM region in order to make the EAM region transparent to the
wavelengths generated and selected by the waveguide section and DBR
section, respectively. (Id.).
Appellants contend that the Examiner has ignored the meaning of
“butt-coupled” as defined in the Specification and that Mason describes a
single waveguide, not three separate but abutting waveguides. (App. Br. 36-
37). Appellants also argue that Mason discloses a fundamentally different
structure than the claimed semiconductor opto-electronic component. (App.
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Br. 37). Appellants contend that Joyner does not disclose separate
waveguides and does not suggest varying the thickness of adjoining butt-
coupled or other wave guide sections. (App. Br. 40-41).

ISSUES
Have Appellants shown that the Examiner reversibly erred in finding
that Mason discloses the waveguide structure recited in the claims?
Have Appellants shown that the Examiner reversibly erred in
determining that it would have been obvious to vary the thickness of the
waveguide sections in Mason’s device in view of Joyner’s disclosure?

FINDINGS OF FACT
The record supports the following findings of fact (FF) by a
preponderance of the evidence.
1. Appellants’ Specification states:
The term “butt-coupled” is used herein to describe a
semiconductor material optoelectronic component in which
adjacent optoelectronic sections of the component have, on
one side of a junction between adjacent sections, one or
more semiconductor layers that have been grown (for
example using MOVCD techniques) up against other
previously formed semiconductor material on the other side
of the junction.
(Spec. 2, l. 31 – 3, l. 6).

2. Appellants’ Specification states:
According to the invention, there is provided a
semiconductor optoelectronic component, comprising a
waveguide section for guiding optical radiation, a
Distributed Bragg Reflector (DBR) section for wavelength-
selecting optical radiation received from the waveguide
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section and an Electro-absorption Modulator (EAM) section
for modulating optical radiation received from the DBR
section, in which each section has a waveguide layer for
conveying said optical radiation, said sections being
monolithically integrated on a common semiconductor
substrate, the DBR section lying between the waveguide
section and the EAM section with the waveguides of
adjacent sections being butt-coupled and aligned so that
optical radiation may be conveyed between adjacent
sections.
(Spec. 4, ll. 8-20).

3. Mason describes a semiconductor optoelectronic component
including a waveguide laser section for guiding optical radiation, a
DBR section for wavelength selecting optical radiation received
from the waveguide section, and an EAM section for modulating
optical radiation received from the DBR section, each having a
waveguide layer for conveying the optical radiation and
monolithically integrated on a common semiconductor substrate.
(Fig. 1, 2; p. 4, l. 22 – p. 5, l. 19).
4. Mason’s Figure 2 is reproduced below:

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Figure 2 depicts a cross section of a semiconductor laser and integrated
electro-absorption modulator, including waveguide 22, EAM 20, gain
section 16 [waveguide laser section], sampled grating front mirror section
18 [DBR section]. (P. 4, l. 23 – p. 5, l. 13; Ans. 3 and 6).
5. Mason states that “[a] key design element of the present invention
is that a single common waveguide 22 is used for tuning sections
12, 14, 16, 18, in the laser 10, and for the modulator 20.” (P. 5, ll.
15-19).
6. Joyner describes monolithic chips with waveguides having an
array of modulated sources, including EA modulators and DBR
sources. (Para. [0038] and [0043]).
7. Joyner discloses that changes in thickness of the various active
regions may be used to vary bandgaps “forming a series of
progressively wavelength-shifted active regions capable of
generating different lasing wavelengths which can be selectively
provided to be within a standardized wavelength grid.” (Para.
[0085]).

PRINCIPLES OF LAW
A patent applicant is free to recite features of an apparatus either
structurally or functionally. In re Schreiber, 128 F.3d 1473, 1478 (Fed. Cir.
1997). Where the Patent Office has reason to believe that a functional
limitation asserted to be critical for establishing novelty in the claimed
subject matter may, in fact, be an inherent characteristic of the prior art, it
possesses the authority to require the applicant to prove that the subject
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matter shown to be in the prior art does not possess the characteristic relied
on. Id. The structure of the prior art apparatus must merely be capable of
performing the claimed functional recitation. Schreiber, 128 F.3d at 1478-
79.
“Where a product-by-process claim is rejected over a prior art product
that appears to be identical, although produced by a different process, the
burden is upon the applicants to come forward with evidence establishing an
unobvious difference between the claimed product and the prior art
product.” In re Marosi, 710 F.2d 799, 803 (Fed. Cir. 1983).
Appellants have the burden on appeal to the Board to demonstrate
error in the Examiner's position. See In re Kahn, 441 F.3d 977, 985-86 (Fed.
Cir. 2006) (“On appeal to the Board, an applicant can overcome a rejection
[under § 103] by showing insufficient evidence of prima facie obviousness
or by rebutting the prima facie case with evidence of secondary indicia of
nonobviousness.”) (quoting In re Rouffet, 149 F.3d 1350, 1355 (Fed. Cir.
1998)).

ANALYSIS
Our discussion focuses on appealed claims 1, 5, and 6, which contain
claim limitations representative of the arguments made by Appellants for
each ground of rejection pursuant to 37 C.F.R. § 41.37(c)(1)(vii).3
Appellants contend that at least eight separate structural elements
recited in the claims are not present in Mason. (App. Br. 36). However,

3 Only those arguments actually made by Appellants have been considered in
this decision. Arguments which Appellants could have made but chose not
to make have not been considered and are deemed to be waived. See 37
C.F.R. § 41.37(c)(1)(vii) (2007).
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Appellants only argue that Mason fails to disclose the presence of three
separate waveguides that are “butt-coupled” with any particularity.
We are not persuaded by Appellants’ arguments that because the
claims recite a “first waveguide,” a “second waveguide,” and a “third
waveguide,” that the structures of the waveguide laser section, the DBR
section, and the EAM section are different than the corresponding sections
of Mason. Both Appellants’ Specification and Mason disclose three
waveguide “sections” that are monolithically integrated onto a
semiconductor substrate. (FF 2, 3). As detailed by the Examiner in the
Answer, Mason discloses three separate sections that correspond to
Appellants’ claimed sections. (Ans. 6-8). Although Mason states that these
sections are part of a common waveguide, Appellants have not directed us to
any persuasive evidence in the record that there is any structural difference
between Appellants’ claimed device and Mason’s device based on the
language of the appealed claims. Further, we decline to read any additional
structure pertaining to the waveguide sections disclosed in the Specification
into the claims.
Appellants have also not presented any persuasive evidence that the
term “butt-coupled” as defined in the Specification imparts any structural
difference between Mason’s device and the claimed opto-electronic
component. (Ans. 8). The Examiner found that Mason’s waveguide
sections are butt-coupled, because they are joined end-to-end and are
contiguous due to being monolithically formed. (Ans. 7-8). Although
Appellants contend that Mason discloses a single wave guide, and not three
“butt-coupled” waveguides, Appellants have not adequately explained why
butt-coupling three separate waveguides as in the claimed semiconductor
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component imparts a structural difference from Mason’s monolithically
integrated waveguide structure.4
Similarly, we are not persuaded by Appellants’ argument that Mason
has a structure fundamentally different than the structures recited in the
claims by disclosing front and back mirror sections 12 and 18. (App. Br.
37). We agree with the Examiner that the open language of the claims does
not exclude any additional sections that may be present in Mason. (Ans. 8).
Regarding claims 5 and 6, Appellants additionally argue that Joyner
does not disclose varying the thickness of adjoining butt-coupled or other
waveguide sections to achieve better optical alignment and transmissivity or
for any other purpose. We are not persuaded by Appellants’ argument as
Appellants have not identified any error in the Examiner’s rationale that
Joyner discloses that layer thickness may be varied for transparence to DFB
generated light. (See Ans. 10).

CONCLUSION
Appellants have failed to demonstrate that Examiner reversibly erred
in finding that Mason discloses the waveguide structure recited in the
claims.
Appellants have failed to demonstrate that the Examiner reversibly
erred in determining that it would have been obvious to vary the thickness of
the waveguide sections in Mason’s device in view of Joyner’s disclosure.

4 We note that Joyner discloses that butt-coupling is a conventional technique
employed for bandgap shifting. (See para. [0062]).
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ORDER
We affirm the Examiner’s decision rejecting claims 1-4 and 8-11
under 35 U.S.C. § 102(b) as being anticipated by Mason. We affirm the
Examiner’s decision rejecting claims 5 and 6 under 35 U.S.C. § 103(a) as
being unpatentable over Mason in view of Joyner.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. §1.136(a)(1)(v).
AFFIRMED

sld

KATHY MANKE
AVAGO TECHNOLOGIES LIMITED
4380 ZIEGLER ROAD
FORT COLLINS, CO 80525