Ex Parte Lee et al

Patent Trial and Appeal BoardDec 26, 2012

12197658 (P.T.A.B. Dec. 26, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE _____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD _____________ Ex parte MICHAEL G. LEE, ALEXEI L. GLEBOV, and DASHUN STEVE ZHOU _____________ Appeal 2010-007651 Application 12/197,658 Technology Center 2800 ______________ Before DAVID M. KOHUT, BRYAN F. MOORE, and MICHAEL J. STRAUSS, Administrative Patent Judges. MOORE, Administrative Patent Judge. DECISION ON APPEAL Appeal 2010-007651 Application 12/197,658 2 This is a decision on appeal under 35 U.S.C. § 134(a) of the Final Rejection of claims 1-8. App. Br. 2. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. INVENTION The invention is directed to optics and more particularly to an optical modulator See Spec. 1. Claim 1 is exemplary of the invention and reproduced below: 1. An optical modulator comprising: an input waveguide; a splitting point operable to split an incoming continuous wave light beam received via the input waveguide into a first light beam and a second light beam, the incoming continuous wave light beam comprising a first wavelength of light and a second wavelength of light; a first interaction arm coupled to the input waveguide at the splitting point, the first interaction arm having a first length L1 and operable to transmit the first light beam; a second interaction arm coupled to the input waveguide at the splitting point, the second interaction arm having a second length L2 unequal in length to the first interaction arm and operable to transmit the second light beam; and an output waveguide coupled to the first interaction arm and the second interaction arm at a recombination point such that the first light beam and second light beam are combined into an output modulated light beam, wherein the first interaction arm and the second interaction arm comprise an electro-optic material with a refractive index that changes according to a modulation stimulus, the electro-optic material having a first refractive index n1 before the modulation stimulus is applied, and a second refractive index n2 after the modulation stimulus is applied, the first length L1 and the second length L2 comprising Appeal 2010-007651 Application 12/197,658 3 lengths such that the output modulated light beam does not comprise the first wavelength of light and the second wavelength of light when the modulation stimulus is applied, and comprises the first wavelength of light and the second wavelength of light when the modulation stimulus is not applied, the first wavelength of light and the second wavelength of light being substantially unattenuated when the stimulus is not applied. REFERENCES Wolf US 5,611,007 Mar. 11, 2007 Ed. L. Wooten, et al. (Wooten) Rapidly tunable narrowband wavelength filter using LiNbO3 unbalanced Mach-Zehnder interferometers. IEEE Journal of Lightwave Technology, vol. 14, no. 11 pp. 2530-2536, November 1996. REJECTIONS AT ISSUE Claims 1, 2, 5, and 6 stand rejected under 35 U.S.C. § 102(b) as being anticipated by Wooten. Ans. 4-7. Claims 3, 4, 7, and 8 stand alternatively rejected under 35 U.S.C. § 103(a) as being unpatentable over Wooten and Wolf. Ans. 8-13. ISSUES 1. Did the Examiner err finding that Wooten discloses “the output modulated light beam does not comprise the first wavelength of light and the second wavelength of light when the modulation stimulus is applied, and comprises the first wavelength of light and the second wavelength of light when the modulation stimulus is not applied, the first wavelength of light and the Appeal 2010-007651 Application 12/197,658 4 second wavelength of light being substantially unattenuated when the stimulus is not applied [,]” as recited in claim 1? 2. Did the Examiner err finding that Wolf discloses the limitations in claim 4? ANALYSIS 35 U.S.C. § 102(b) - Wooten Claims 1, 2, 5, and 6 With respect to the above rejection, Appellants present arguments with respect to claim 1. As to Claim 1, Appellants argue that “a three-stage filter in which one out of eight wavelengths of light is passed when a stimulus is applied” does not meet the limitation cited in issue 1 above. App. Br. 12. Appellants argue that “Figure 2 illustrates how one set of frequencies are passed when no stimulus is applied, and a completely different set of frequencies are attenuated when a stimulus is applied.” Id. at 13. Finally, Appellants argue, as to the Examiner’s statement that a voltage equal to the half-wave voltage is inherent, “merely stating that a certain voltage inherently exists to produce a claimed effect does not meet or even address this standard that the allegedly inherent characteristic necessarily flows from the prior art.” Id at 14. We are not persuaded by these arguments. As to Figure 2, the Examiner notes that Figure 2 shows “an inherent sinusoidal transmission characteristic” of the Mach-Zehnder modulator with three different arms length differences. Ans. at 14-15. The Examiner is relying on the fact that the curve shows that, for a given arm length difference, there is a characteristic when no stimulus is applied. As the Appeal 2010-007651 Application 12/197,658 5 Examiner points out, Fig. 2 shows the characteristic curves when the voltage is fixed at zero. Ans. 14. Therefore, Figure 2 does not show a completely different set of frequencies when a stimulus (i.e., non-zero voltage) is applied. What Fig. 2 does show is two or more wavelengths (such as 100 GHz and 200 GHz on the solid curve) that correspond to the maxima (a Transmittance of 1) in the absence of a modulation stimulus (V=0) and hence both wavelengths are transmitted through the output waveguide substantially unattenuated. See Ans. 6 (citing Wooten Fig. 2.) Thus, Wooten discloses “the output modulated light beam . . . comprises the first wavelength of light and the second wavelength of light when the modulation stimulus is not applied, the first wavelength of light and the second wavelength of light being substantially unattenuated when the stimulus is not applied.” Therefore Wooten satisfies at least the final portion of the disputed limitation. Claim 1 also recites “the output modulated light beam does not comprise the first wavelength of light and the second wavelength of light when the modulation stimulus is applied.” As noted above, Appellants’ argue that the Examiner has improperly relied on inherency to show this limitation. “A single prior art reference that discloses, either expressly or inherently, each limitation of a claim invalidates that claim by anticipation.” Perricone v. Medicis Pharmaceutical Corp., 432 F.3d 1368, 1375 (Fed. Cir. 2005). In Cruciferous Sprout, the court stated “[i]t is well settled that a prior art reference may anticipate when the claim limitations not expressly found Appeal 2010-007651 Application 12/197,658 6 in that reference are nonetheless inherent in it.” In re Cruciferous Sprout Litigation, 301 F.3d 1343, 1349 (Fed. Cir. 2002). Inherent anticipation requires that the missing descriptive material is “necessarily present,” not merely probably or possibly present in the prior art. See In re Robertson, 169 F.3d 743, 745 (Fed. Cir. 1999). The Examiner notes that, according to Eq. 1, when a modulation stimulus is applied with a magnitude equal to the half-wave switching voltage Vπ, the transmission curve shifts by a half a period. Ans. 6. Appellants do not explain why Eq. 1 of Wooten does not lead to this result. Whether the rejection is based on “inherency” under 35 U.S.C. § 102, on “prima facie obviousness” under 35 U.S.C. § 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO’s inability to manufacture products or to obtain and compare prior art products. In re Best, 562 F.2d 1252, 1254-55 (CCPA 1977). Therefore, we agree with the Examiner’s assertion regarding Eq. 1 of Wooten. See Ans. 6. With reference to Fig. 2, if the solid curve is shifted by a half period then the maxima that was shown at 100 GHz shifts to the minima shown at 150 GHz and the same with the maxima 200 GHz, which will shift to the minima shown at 250 GHz. Ans. 6. Figures 4 and 5 shows an arrangement where such an effect is achieved. Id. As illustrated therein, eight wavelengths λ1-λ8 are input to the modulator, four wavelengths λ2, λ4, λ6, λ8 are switched off and four wavelengths λ1, λ3, λ5, λ7are switched on for the same stimulus voltage input. Ans. 5. Thus initial portion of the disputed limitation is also satisfied by Wooten. Accordingly, based on the forgoing, we agree with the Examiner that the limitations of the claim 1 are each disclosed necessarily if not explicitly by Wooten. Therefore, for the reasons Appeal 2010-007651 Application 12/197,658 7 stated above, we sustain the Examiner’s rejection of claim 1 and claim 2 which depends from claim 1 and claims 5, and 6 which are not separately argued. 35 U.S.C. § 103(a) - Wooten and Wolf Claims 3, 4, 7, and 8 With respect to the above rejection, Appellants provide arguments regarding claim 4. Claim 4 recites “wherein the difference ΔL between L1 and L2 is found according to [a certain] equation.” Appellants also argue “the Examiner makes broad generalizations and assumptions that are not supported by the references” and thus the references do not show deriving or calculating using the claimed equation. App. Br. 16-17. We find that an ordinarily skilled artisan would have appreciated that optimizing the ΔL by derivation of the cited equation, in light of the teachings of Wooten and Wolf, involves only a design choice using routine skill in the art. See Ans. 16. A design choice may be an acceptable rationale for an obviousness rejection when a claimed product merely arranges known elements in a configuration that provides no novel or unexpected results. See In re Kuhle, 526 F.2d 553, 555 (CCPA 1975). An improvement in the art is obvious if “it is likely the product not of innovation but of ordinary skill and common sense.” KSR Int'l v. Teleflex Inc., 550 U.S. 398, 421 (2007). Moreover, the obviousness analysis “need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court [or the PTO] can take account of the inferences and creative steps that a person of ordinary skill in the art would employ.” KSR, 550 U.S. at 418. The knowledge to be taken into account includes knowledge generally available to a person Appeal 2010-007651 Application 12/197,658 8 having ordinary skill in the art, and facts admittedly well known in the art. See In re Paulsen, 30 F.3d 1475, 1480 (Fed. Cir. 1994) (“[A] prior art reference must be ‘considered together with the knowledge of one of ordinary skill in the pertinent art.”’); In re Sovish, 769 F.2d 738, 743 (Fed. Cir. 1985) (skill is presumed on the part of the artisan, rather than the lack thereof); and In re Nomiya, 509 F.2d 566, 570-71 (CCPA 1975) (The admittedly known prior art disclosed in an appellant's specification may be used in determining the patentability of a claimed invention.). Here Wooten shows the need to properly design an optical modulator so that at least two wavelengths are switched off for the same applied switching voltage. The disclosed modulator also would be recognized by one skilled in the art to operate such that it would transmit the at least two wavelengths substantially unattenuated when no voltage is applied, as detailed above, thus disclosing the desirability of deriving or solving a known set of equations to calculate a required ΔL. Ans. 16. We agree with the Examiner that “[s]ince the transmission/switching characteristic T depends on ΔL, as evident from Eqs. (1) - (2) and Fig. 2, Wooten, at the very least, makes the need to optimize ΔL obvious to a person of ordinary skill in the art, while the corresponding analysis would have been very straightforward and well within the skill of such person.” Id. Additionally, we note that equation 4 of Wolf shows a deviation of a similar equation based on a Mach-Zehnder device with the same variables. Appellants have not argued, nor do we find, any unexpected results in regard to deriving the equation recited in claim 4. Therefore, for the reasons stated above, we sustain the Examiner’s rejection of claim and claims 3, 7, and 8 which are not separately argued. Appeal 2010-007651 Application 12/197,658 9 DECISION The Examiner’s decision to reject claims 1-8 is affirmed. 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)(iv). AFFIRMED ELD