Non-Final Rejection
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claims 1-20 are pending.
The examiner issued a restriction requirement on 2/2/2026. Applicant’s election without traverse of group I, claims 1-4 and 15-20, in the reply filed on 3/16/2026 is acknowledged. Claims 5-14 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Note that none of claims 5-14 include all of the limitations of any allowable claim, therefore rejoinder is not appropriate. See MPEP 821.04. Claim 13 is close but not quite there. If applicant amends claims 5-14 to depend from or include all of the limitations of an allowable claim then rejoinder will be reconsidered. If this does not occur and all pending claims of group I become allowable, the withdrawn claims will be cancelled by examiner’s amendment. See MPEP 821.02.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 4 and 20 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Claims 4 and 20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
These rejections are ultimately caused by the same issue. The examiner believes both are appropriate, so both are applied.
Each claim requires that “wherein in each of the plurality of InAlGaAs quantum well layers, a mass percentage of indium (In) is 53%, a mass percentage of aluminum (Al) is 36%, and a mass percentage of gallium (Ga) and a mass percentage of arsenide (As) sum to 11%.” However, this does not make sense given how a person of ordinary skill in the art would understand such a compound to be made. The three group III elements (In, Al, Ga) will generally be in a 1:1 atomic ratio with the group V element (As); it is more accurately written as InxAlyGa1-x-yAs. Given the atomic weight of these elements, and that As will be half of the atomic percentage of the compound, the examiner fails to see how arsenic, even with gallium, will only be 11% of the mass percentage while indium is at 53% and aluminum at 36%. It is assumed that applicant meant to make some requirement about atomic percentage,1 as this is the more typical way of talking about these things. Even so, in the above case gallium alone would be 11%, not the combination of gallium and arsenic. It is additionally noted that nothing about atomic percentage is in the specification so any such addition now would be new matter. If applicant did in fact mean mass percentage it should show an example compound that meets these values.
Given the above, as the examiner cannot see a compound that can meet the claims, the examiner therefore does not see how a person skilled in the art could make or use the claimed invention and these claims are rejected for lack of enablement. Alternatively, as it is not clear to the examiner what compound would meet the claim, the metes and bounds of the claim are unclear and indefinite.
Allowable Subject Matter
Claims 1-3 and 15-19 are allowed. The following is a statement of reasons for allowance:
Regarding claim 1, there is not taught or disclosed in the prior art a quantum well structure for DFB lasers including InAlGaAs and InAlAs layers as claimed, where the thickness of each is the same and ranges from 0.4 to 0.6 nm.
It was known in the art to have quantum well structures including these materials. Several references are cited with this action and show this. However, it was not known in the art to have such a structure where the layers are the same thickness and also have a thickness in this range.
It is noted that this is much thinner than is typical of quantum well layers, but applicant has a rationale for using these materials and thicknesses—as applicant explains, all of these things affect the well confinement factor. When the thicknesses are the same, and when both are made thin, the quantum well confinement parameter is increased. [0048]-[0053], [0059]. This lowers the threshold current, which is generally advantageous for lasers. It cannot merely be an obvious optimization to change the thickness when applicant has established its criticality. MPEP 2144.05 III.A.
Claim 15 is more detailed but includes the same features.
In the parent PCT application, the PCT examiner cited US 2020/0278589, which shows a quantum well structure having the above materials, but the layers have different thicknesses and also far greater thicknesses (more than 10 times the claimed thickness, which in the examiner’s search is typical). The examiner stated that changing the thicknesses to be the same and as claimed would not involve inventive step. The examiner does not agree that this reference or those like it makes the claims obvious under U.S. law. Making the layers an order of magnitude thinner is not a simple change that one can handwave away, particularly given that the thickness has criticality in the specification as discussed above. With no reason and for such a large change, going down to the claimed range is only deemed hindsight. The thicknesses are additionally very different, over 40% different, and again there is no reason to just make them the same other than hindsight. It is also noted that the quantum wells in this reference are not for a laser (it is a modulator) and twice as many layers are used as those claimed.
In a related European application, the examiner cited the Liu reference (see 3/31/2025 IDS) which shows layers having almost similar thickness (0.61 and 0.62 nm). First, these thicknesses are not the same, and are not within the claimed range. Additionally, one of the layers is InGaAs, i.e. it is not the same material as claimed. The examiner stated that there was no inventive step because the thickness difference was not significant and a person skilled in the art could add aluminum to the InGaAs layer. The examiner does not agree that this reference makes the claims obvious under U.S. law. There is no reason to add aluminum to the compound other than hindsight to reach the claim. The particular materials were chosen in Liu to yield a structure overall equivalent to a particular AlGaInAs compound, and there is no reason to upset that approach by changing the amount of aluminum in one of the layers. Additionally, Liu specifically makes the thicknesses of these layers different for a reason, to introduce strain, and there is likewise no reason to upset that approach by changing the thicknesses of the layers. Both of these changes would go against what Liu is explicitly intending to do.
Furthermore, even if these layers were adequate they are not actually “quantum well” layers as claimed. These ~6 angstrom layers are the beginning product used to create the well layers. See last par. of section II. The well layers themselves that are created are far thicker, 95 angstroms for the well and 50 for the barrier. See first par. of section II. A person of ordinary skill in the art would not consider these to be quantum well layers in light of how the layers are described in the specification. See Fig. 9 and discussion. The 95 and 50 angstrom layers are clearly what would apply, and once again the thickness is far different.
Again, a number of references are cited showing quantum wells of these materials, but none have the claimed thicknesses. Thicknesses are either not disclosed at all, or are generally 10 times greater than the claimed range. Again, it is not deemed obvious to change the thickness by an order of magnitude, particularly when the thickness is deemed critical.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to James Menefee whose telephone number is (571)272-1944. The examiner can normally be reached M-F 7-4.
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/JAMES A MENEFEE/Primary Examiner, Art Unit 2828
1 It is noted that in both the 8/29/2024 response in the related Japanese application JP 2023-540828 and in the 2/26/2025 response in the related European application EP 21913769, applicant conceded this was a clerical mistake and atomic percentage was meant.
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