Ex parte HUBER

Board of Patent Appeals and Interferences

Mar 24, 1999

08152315 (B.P.A.I. Mar. 24, 1999)

Appeal No. 96-3896
Application No. 08/152,315
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered
today (1) was not written for publication in a law
journal and (2) is not binding precedent of the
Board.
Paper No. 23
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte DAVID R. HUBER
____________
Appeal No. 96-3896
Application No.08/152,3151
____________
ON BRIEF
____________
Before URYNOWICZ, THOMAS, and CARMICHAEL, Administrative Patent Judges.
URYNOWICZ, Administrative Patent Judge.
Appeal No. 96-3896
Application No. 08/152,315
2
DECISION ON APPEAL
This appeal is from the final rejection of claims 6
and 8, all the claims pending in the application.
Claim 6 defines an optical multiplexer and claim 8
defines an optical demultiplexer. Claims 6 and 8 read as
follows:
An optical multiplexer for multiplexing optical
signals having different wavelengths comprising:
an optical circulator having at least three
circulator ports (1, 2, 3) for circulating optical signals
from one port to the next port in a circulating direction;
means for coupling a first optical signal at a first
wavelength (ë ) to a first of said circulator ports (1);j
an in-fiber Bragg grating reflector for reflecting
substantially only said first optical signal at said first
wavelength (ë );j
means for coupling said in-fiber Bragg grating
reflector to a second of said circulator ports (2) which is
the next circulator port in the circulating direction from
said first circulator port (1) for reflecting said first
optical signal at said first wavelength (ë ) back to saidj
second circulator port (2);
means for coupling a multiplexed optical signal ëk,
the multiplexed signal ë comprising a group of opticalk
signals, each at a different wavelength, wherein the
Appeal No. 96-3896
Application No. 08/152,315
3
multiplexed optical signal ë does not include an opticalk
signal at a wavelength of ë to said in-fiber Bragg gratingi
reflector for transmission to said second circulator port (2);
and
both of said optical signals being circulated from
said second circulator port (2) to said third circulator port
(3) which is the next port in the circulating direction so
that a combined multiplexed output of said optical signals is
coupled from said third circulator port (3).
8. An optical demultiplexer for demuliplexing [sic]
an input signal containing a group of signals each at a
different wavelength (ë ë ë ë ) into at least two opticalk = 1, 2 . . . j
signals comprising:
an optical circulator having at least three
circulator ports (1, 2, 3) for circulating optical signals
from one port to the next port in a circulating direction;
means for coupling said input signal comprising a
group of signals each at a different wavelength (ë ) to ak
first of said circulator ports (1);
an in-fiber Bragg grating reflector for reflecting
substantially only a desired one of said optical signals at a
first wavelength (ë );j
means for coupling said in-fiber Bragg grating
reflector to a second of said circulator ports (2) which is
the next circulator port in the circulating direction from
said first circulator port (1) for reflecting said desired one
of said optical signals at a first wavelength (ë ) back toj
said second circulator port (2);
said desired one of said two optical signals at a
first wavelength (ë ) being circulator from said secondj
Appeal No. 96-3896
Application No. 08/152,315
4
circulator port (2) to said third circulator port (3) which is
the next port in the circulating direction so that the
demultiplexed output of said desired one of said optical
signals at a desired wavelength (ë ) is coupled from saidj
third circulator port (3).
The references relied upon by the examiner as
evidence of obviousness are:
DeLange 3,676,684 Jul. 11, 1972
Hepner et al. (Hepner) 4,221,460 Sep. 09, 1980
Glomb et al. (Glomb) 5,077,816 Dec. 31, 1991
The appealed claims stand rejected as under 35
U.S.C.
' 103 as being unpatentable over Hepner or DeLange in view of
Glomb.
The respective positions of the examiner and the
appellant with regard to the propriety of these rejections are
set forth in the final rejection (Paper No. 14) and the
examiner's answer (Paper No. 22) and the appellant's brief
(Paper No. 21).
Appellant's Invention
Appeal No. 96-3896
Application No. 08/152,315
5
The invention relates to optical multiplexers and
demultiplexers which use Bragg grating reflectors to select
optical channels in wavelength division multiplexed optical
communication systems. In the multiplexer of Figure 2, a
three-port optical circulator 36 circulates optical signals
from one port to the next port. For example, optical signals
which enter port 1 exit at port 2, and optical signals which
enter port 2 exit at port 3. An optical signal having a first
wavelength ë is coupled to circulator port 1 at input 30. j
This signal exits circulator 36 through circulator port 2.
The exiting optical signal encounters an in-fiber Bragg
grating reflector 38 and is reflected back through circulator
port 2. A multiplexed optical signal ë is coupled at inputk
32 to the reflector 38 for transmission into circulator port
2. The multiplexed signal ë comprises a group of opticalk
signals, each at a different wavelength. The multiplexed
optical signal ë and the optical signal ë are circulated fromk j
circulator port 2 to circulator
Appeal No. 96-3896
Application No. 08/152,315
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port 3, creating a multiplexed output optical signal comprised
of ë and ë on output path 34.j k
In the demultiplexer of Figure 3, a three-port
optical circulator 36 circulates optical signals from one port
to the next. That is, optical signals which enter port 1 exit
at port 2 and optical signals which enter port 2 exit at port
3. A Bragg grating reflector 46 selects an optical channel to
be removed from the optical system. A multiplexed optical
signal ë comprised of a group of signals is coupled tok
circulator port 1 through input path 42. Reflector 46
reflects an optical wavelength ë . The multiplexed opticalj
signal input at port 1 exits the optical circulator at port 2.
The optical wavelength ë is reflected by the Bragg gratingj
and re-enters the optical circulator through port 2. The
remaining wavelengths of the multiplexed optical signal are
transmitted through grating reflector 46 to output 48. The
demultiplexed optical signal ë j
is circulated from circulator port 2 to circulator port 3
where it exits onto output 44.
Appeal No. 96-3896
Application No. 08/152,315
7
The Prior Art
In Figure 2, DeLange discloses an optical
multiplexer comprising a plurality of branches 1-N, each of
which selectively isolates and modulates one of a plurality of
carrier signals F -F input at ports 1 of discriminators 11. 1 N
The modulated signals are either reflected at filters F to
rejoin the unmodulated carriers or they are separated at the
filters and combined in a separate output circuit comprising
modulators 14. A demulti-plexer (Figure 5) selectively
isolates modulated carriers by means of a network similar to
the multiplexer, and demodulates them in turn.
In Figure 4, Hepner discloses an optical multiplexer
for multiplexing two optical signals having wavelengths ë and1
ë input at terminals 1 and 2, respectively. Filter 12 is2
selected to transmit the signal having ë and to reflect the2
signal having ë . The signal at 1 (ë ) passes through1 1
separator 8, the rotator 9 and half-wave plate 4. It is
reflected by filter 12, passes through plate 4, rotator 9,
separator 8, plate 6 to output
Appeal No. 96-3896
Application No. 08/152,315
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terminal 3. The signal at 2 (ë ) passes through filter 12 and2
takes the same path as ë to output terminal 3. 1
For demultiplexing, two carrier signals having
wavelength ë and ë are input at terminal 1. These signals1 2
pass through separator 8, rotator 9 and the half-wave plate 4.
Filter
12 reflects the carrier wavelength ë and transmits the1
carrier wave of ë to line 2. The carrier signal of wavelength2
ë is thus obtained at the output end of the filter on line 3. 1
When reflected, carrier ë is passed back through the half-1
wave plate 4 and the rotator 9. The separator 8 deflects the
signal, which then passes through half-wave plate 6 to output
line 3.
Glomb teaches optical communication devices
utilizing Bragg grating elements. As illustrated in Figure 2,
such elements have wide frequency pass bands on each side of a
narrow reflection band 22.
Appeal No. 96-3896
Application No. 08/152,315
9
Opinion
After consideration of the positions and arguments
presented by both the examiner and the appellant, we have
concluded that the rejection of claims 6 and 8 over DeLange in
view of Glomb should not be sustained, that the rejection of
claim 6 over Hepner in view of Glomb should not be sustained
but that the rejection of claim 8 over Hepner in view of Glomb
should be sustained.
With respect to the rejection of claims 6 and 8 over
DeLange and Glomb, the filters 13 and 32 of DeLange=s device,
Figures 2 and 5, respectively, pass a single wavelength and
reflect all others. In contrast, the Bragg grating filter of
Glomb, having a narrow stopband 22, passes most wavelengths
and reflects a narrow band of wavelengths. Such being the
case, there is no motivation to substitute the Bragg grating
filter of Glomb for each of the filters disclosed in DeLange
because with the Bragg grating filters disclosed in Glomb,
Appeal No. 96-3896
Application No. 08/152,315
10
DeLange could no longer function to reflect all but one
frequency at each filter as intended. Thus, with the Bragg
grating filter of Glomb substituted in DeLange, DeLange could
not function in the manner disclosed.
As to the rejection of claim 6 over Hepner and
Glomb, it is considered that the substitution of the Bragg
grating filter for the filter in Hepner would have been
obvious to one of ordinary skill in the art at the time the
invention was made. Hepner=s filter 12, Figure 4, operates to
pass a wavelength and reflect a second, different wavelength.
The Bragg grating of Glomb is disclosed at column 5, lines 17-
38, and at Figure 2, and it is apparent that it reflects a
wavelength within stopband 22 and passes any wavelength
outside of the stopband. Thus, the fact that the grating
would have served as a full substitute for Hepner=s filter is
apparent. Section 103 requires us to presume that the artisan
has full knowledge of the prior art in his field of endeavor
and the ability to select and utilize knowledge from analogous
arts. In re Deminski, 796 F.2d 436, 442, 230 USPQ 313, 315
Appeal No. 96-3896
Application No. 08/152,315
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(Fed. Cir. 1986). Nevertheless, the combination does not
result in the claimed invention. Hepner does not disclose
means for coupling a group of optical signals ë to a secondk
circulator port as recited in claim 6 and it has not been
established why it would have been obvious to one of ordinary
skill in the art to modify the combined teachings of the prior
art so as to utilize such a group of signals for the single
wavelength signal applied to the second circulator port of
Hepner.
Claim 8 requires no more than two optical signals
and thus, does not distinguish over the combination of Hepner
and Glomb. The two signals of claim 8 are met by the two
signals having wavelengths ë and ë applied at circulator port1 2
1 in Figure 4 of Hepner in the demultiplexing of the two
signals disclosed at column 4, line 58 through column 5, line
6.
Appeal No. 96-3896
Application No. 08/152,315
12
No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
' 1.136(a).
AFFIRMED-IN-PART
STANLEY M. URYNOWICZ, JR. )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
JAMES D. THOMAS ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
JAMES T. CARMICHAEL )
Administrative Patent Judge )
Appeal No. 96-3896
Application No. 08/152,315
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SMU/dal
Appeal No. 96-3896
Application No. 08/152,315
14
Application for patent filed November 15, 1993. 1
According to appellant, this application is a Division of
Application 07/919,823 filed July 27, 1992, now U.S. Patent
No. 5,283,686 issued February 1, 1994.
MARSHALL, O=TOOLE, GERSTEIN,
MURRAY and BORUN
6300 SEARS TOWER
233 SOUTH WACKER DRIVE
CHICAGO, IL 60606-6402