Dazeng Feng et al.

Patent Trials and Appeals Board

Sep 26, 2019

14048685 - (D) (P.T.A.B. Sep. 26, 2019)

UNITED STATES PATENT AND TRADEMARK OFFICE
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.
14/048,685 10/08/2013 Dazeng Feng LT3900 2668
26138 7590 09/26/2019
Joseph R. Baker, APC
Gavrilovich, Dodd & Lindsey LLP
4370 La Jolla Village Drive, Suite 303
San Diego, CA 92122
EXAMINER
TAVLYKAEV, ROBERT FUATOVICH
ART UNIT PAPER NUMBER
2883
MAIL DATE DELIVERY MODE
09/26/2019 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 PATENT TRIAL AND APPEAL BOARD
____________

Ex parte DAZENG FENG and MEHDI ASGHARI
____________

Appeal 2018-007751
Application 14/048,685
Technology Center 2800
____________
Before GEORGE C. BEST, MERRELL C. CASHION, JR., and
JANE E. INGLESE, Administrative Patent Judges.
BEST, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claim 1 of Application 14/048,685.2 We have
jurisdiction under 35 U.S.C. § 6(b).
For the reasons set forth below, we affirm.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the real party in interest as Mellanox
Technologies Silicon Photonics, Inc. Appeal Br. 1.
2 In the Final Action, the Examiner rejected claims 1, 2, 4–7, and 9–22. Final
Act. (November 8, 2016). Appellant subsequently cancelled claims 2, 4–7,
and 9–22. Amendment (April 26, 2018) (entered by the Examiner July 23,
2018).
Appeal 2018-007751
Application 14/048,685
2
BACKGROUND
Claim 1 is the only claim pending in the ’685 Application and is
reproduced below from the Claims Appendix of the Appeal Brief.
1. An optical system, comprising:
an optical modulator configured to guide a first light
signal through an electro-absorption medium, the first light
signal having a first wavelength;
a light sensor configured to guide a second light signal
through a light-absorbing medium, the second light signal being
derived from the first light signal and having the first
wavelength;
the light-absorbing medium and the electro-
absorption medium being the same material; and
a heater positioned so as to elevate a temperature of the
light sensor.
Appeal Br. 12.
REJECTION
Claim 1 is the only claim remaining in the ’685 Application. Claim 1
is rejected under 35 U.S.C. § 103 as unpatentable over the combination of
Lim3 and Miller.4 Final Act. 9.
DISCUSSION
In rejecting claim 1, the Examiner found that Lim describes each
limitation of claim 1 except for the requirement of the system comprising “a

3 Andy Eu-Jin Lim et al., Novel evanescent-coupled germanium electro-
absorption modulator featuring monolithic integration with germanium p-i-
n photo detector, 19 Optics Express 5040 (2011).
4 US 7,515,776 B1, issued April 7, 2009.
Appeal 2018-007751
Application 14/048,685
3
heater positioned so as to elevate a temperature of the light sensor.” Final
Act. 10. The Examiner further found that
Lim considers (Section 3) a correspondence/matching
between the spectral/wavelength ranges of operation of the
modulator and the light sensor, including the C-band of
operation, and cites known techniques of shifting/tuning the
spectral ranges to achieve such matching, including a material
composition variation (par. bridging pages 5042 and 5043) and
a proper reverse bias (Fig. 3(b)) to adjust/tune a wavelength of
operation. While Lim does not cite temperature control/tuning
as another well-known mechanism of shifting/tuning a
spectral/wavelength range (absorption edge) of the light sensor
and/or the modulator, Miller teaches (e.g., Figs. 6 and 13;
Abstract, col. 6, lines 30–51; col. 9, line[] 18 through col. 10,
line 20) that the spectral/wavelength range (absorption edge)
can be tuned/shifted by a reverse bias (as in Lim) AND
additionally by temperature control using a heater. Miller
expressly teaches (col. 9, lines 1–8) that the disclosed invention
is applicable to both modulators and detectors (light sensors),
as opposed to lasers which would be adversely affected by
elevated temperatures (col. 9, lines 38–42).
Id. at 10–11.
In particular, the Examiner relies upon Miller’s statement that “[t]his
invention is also applicable to optoelectronic devices other than modulators
(e.g., sources and detectors), and to electronic and spintronic devices.”
Miller 9:6–8.
First, Appellant argues that the rejection should be reversed because
the phrase “this invention” in this passage from Miller does not refer to the
use of heaters. Appeal Br. 8. According to Appellant, the relevant passage in
Miller states that “this invention” may be applied to sources (e.g., lasers),
which means that the phrase “this invention” cannot include heaters because
the performance of a semiconductor laser is degraded by heat. Id. (citing
Miller 9:38–40).
Appeal 2018-007751
Application 14/048,685
4
Appellant’s argument discounts the knowledge of a person of ordinary
skill in the art. As the Examiner explains,
Miller explicitly excludes the use of the heater only for a laser
based on a well-known fact/circumstance that lasers are
adversely affected by elevated temperatures (9:38–42).
Nowhere does Miller state that photodetectors and modulators
are adversely affected by heating and could not be used with a
heater. In fact, Miller directly states, at least for modulators,
another well-known fact that they are not adversely affected by
heating (in contrast to lasers; 9:38–42) and therefore a heater
can be used to locally control the temperature of the modulator
in order to broaden its spectral range/band of optimum
operation/efficiency (9:9–62).
Answer 2; see also Final Act. 4–7.
In view of the foregoing, we are not persuaded that the Examiner
relied on an impermissibly overly broad interpretation of Miller’s statement
that its invention is also applicable to “sources and detectors.”
Second, Appellant argues that “[t]he cited art would not direct an
inventor’s [sic] toward the modification upon which the rejection relies.”
Appeal Br. 9. According to Appellant, Miller’s use of heat to shift
operational wavelength of a modulator is limited to materials including
quantum wells. Id. at 9–10. Because Lim’s modulator does not include
quantum wells, Appellant argues that a person of ordinary skill in the art
would not apply Miller’s methods to Lim’s modulator. Id.
This argument is not persuasive of reversible error. Miller explains
that its device uses effects that are not dependent upon the presence of
quantum wells to achieve the shifts in operational bandwidth:
In the present invention, preferred physical mechanisms do not
rely upon electron confinement in the quantum well, since such
confinement is weak in the SiGe material system. Instead,
preferred physical effects relate to electric field induced shifts
Appeal 2018-007751
Application 14/048,685
5
in the direct absorption edge of the quantum well structure such
as the Quantum Confined Stark Effect (QCSE), the Wannier-
Stark effect, and the Franz-Keldysh [“FK”] effect. These effects
can provide both electro-absorption (i.e., a field-dependent
absorption) and electro-refraction i.e., a field-dependent
refractive index). Devices can be based on one or several of
these effects.
Miller 5:7–17.
As the Examiner states, “Appellant’s remarks are drawn to differences
in [the] physical structures in Lim and Miller, whereas it is the teachings of
Miller (the use of thermal tuning of the spectral band of the photodetector)
that [are] applied to the modulator-photodetector device of Lim.” Answer 3
(emphasis omitted).
For the reasons set forth above, we affirm the rejection of claim 1.
CONCLUSION
In summary:
Claims
Rejected Basis Affirmed Reversed
1 § 103 Lim and Miller 1
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED