Prosecution Insights
Last updated: April 19, 2026
Application No. 18/211,696

CO-ALKALI DOPED OPTICAL FIBERS

Non-Final OA §103
Filed
Jun 20, 2023
Examiner
CHU, CHRIS H
Art Unit
2874
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Corning Incorporated
OA Round
3 (Non-Final)
53%
Grant Probability
Moderate
3-4
OA Rounds
2y 12m
To Grant
63%
With Interview

Examiner Intelligence

Grants 53% of resolved cases
53%
Career Allow Rate
345 granted / 650 resolved
-14.9% vs TC avg
Moderate +10% lift
Without
With
+10.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 12m
Avg Prosecution
44 currently pending
Career history
694
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
74.2%
+34.2% vs TC avg
§102
20.0%
-20.0% vs TC avg
§112
1.8%
-38.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 650 resolved cases

Office Action

§103
Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . DETAILED ACTION Response to Amendment Applicant’s Amendment filed October 22, 2025 has been fully considered and entered. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claims 1 and 6-21 are rejected under 35 U.S.C. 103 as being unpatentable over Peckham et al. (US 2020/0024176 A1). Regarding claim 1, Peckham discloses an optical fiber (Fig. 1) comprising a core region (110) comprising silica glass (paragraph 0018) doped with a first alkali dopant comprising sodium oxide and a second alkali dopant comprising potassium oxide (paragraph 0046 discloses doping Na at the center of the core and K at the core-cladding interface; paragraph 0027 discloses using alkali oxides as dopants), the first alkali dopant having a first average core concentration C1 and a first diffusivity D1, the second alkali dopant having a second average core concentration C2 and a second diffusivity D2, the second diffusivity D2 less than the first diffusivity D1 (diffusivity of K is known to be less than that of Na); and a cladding region (Fig. 1) surrounding the core region. Still regarding claim 1, Peckham discloses the concentration of the dopant at the core-cladding interface lower than that of the dopant at the center of the core in Fig. 6. Peckham teaches the claimed invention except for the first average core concentration C1 and the second average core concentration C2 satisfy a relation 0.10 ≤ C2/C1 ≤ 1.00. However, it would have been obvious to one having ordinary skill in the art at the time of the invention to arrive at the claimed core concentrations in order to control alkali diffusivity in order to reduce devitrification, and since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Regarding claims 6 and 7, Peckham teaches the claimed invention except for the relation of the core concentrations. However, it would have been obvious to one having ordinary skill in the art at the time of the invention to arrive at the claimed core concentrations in order to reduce devitrification, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Regarding claims 8 and 9, Peckham teaches the claimed invention except for the core concentrations of the first and second dopants. However, it would have been obvious to one having ordinary skill in the art at the time of the invention to arrive at the claimed core concentrations in order to reduce devitrification, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Regarding claims 10 and 11, Peckham further discloses a large effective area fiber in paragraph 0023. Peckham teaches the claimed invention except for specifically stating the effective area. However, it would have been obvious to one having ordinary skill in the art at the time of the invention to arrive at the claimed effective area in order to control the output of the optical signal, and since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Regarding claims 12-14, Peckham further discloses reducing the attenuation in paragraphs 0003 and 0042. Peckham teaches the claimed invention except for specifically stating the transmission loss. However, it would have been obvious to one having ordinary skill in the art at the time of the invention to arrive at the claimed transmission loss in order to improve the transmission of the optical signal, and since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Regarding claims 15-18, Peckham further discloses reducing the scattering loss in paragraph 0042. Peckham teaches the claimed invention except for specifically stating the Rayleigh scattering loss and small angle scattering loss. However, it would have been obvious to one having ordinary skill in the art at the time of the invention to arrive at the claimed losses in order to improve the transmission of the optical signal, and since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Regarding claim 19, Peckham teaches the claimed invention except for the core concentrations. However, it would have been obvious to one having ordinary skill in the art at the time of the invention to arrive at the claimed core concentrations in order to reduce devitrification, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Regarding claim 20, Peckham teaches the claimed invention except for the core doped only with the first alkali dopant and the second alkali dopant. However, optical fibers comprising silica cores doped only with alkali dopants are well-known and commonly used in the art and as such, one having ordinary skill would find it obvious to dope the core only with the first alkali dopant and the second alkali dopant in order to reduce the number of components and simplify the manufacturing process thereof. Regarding claim 21, Peckham teaches the claimed invention except for the average core concentration of the first alkali dopant. However, it would have been obvious to one having ordinary skill in the art at the time of the invention to arrive at the claimed average core concentration of the first alkali dopant in order to reduce devitrification, and since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. Response to Arguments Applicant's arguments, filed October 22, 2025, with respect to claims have been considered but are not moot in view of the new grounds of rejection. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRIS H CHU whose telephone number is (571)272-8655. The examiner can normally be reached on Mon-Fri 9AM-5PM. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Uyen-Chau Le can be reached on 571-272-239797. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Any inquiry of a general or clerical nature should be directed to the Technology Center 2800 receptionist at telephone number (571) 272-1562. Chris H. Chu /CHRIS H CHU/Primary Examiner, Art Unit 2874 January 29, 2026
Read full office action

Prosecution Timeline

Jun 20, 2023
Application Filed
Jan 23, 2025
Non-Final Rejection — §103
Apr 24, 2025
Response Filed
Jul 24, 2025
Non-Final Rejection — §103
Oct 22, 2025
Response Filed
Jan 29, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12601871
OPTICAL FIBER
2y 5m to grant Granted Apr 14, 2026
Patent 12596224
MULTI-CLAD OPTICAL FIBERS
2y 5m to grant Granted Apr 07, 2026
Patent 12585071
FIBER OPTIC CABLE ASSEMBLIES WITH IN-LINE TERMINAL ASSEMBLIES AND METHODS OF MAKING AND INSTALLING SAME
2y 5m to grant Granted Mar 24, 2026
Patent 12585062
OPTICAL FIBER
2y 5m to grant Granted Mar 24, 2026
Patent 12571963
POLARIZATION BEAM SPLITTER ROTATOR
2y 5m to grant Granted Mar 10, 2026
Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
53%
Grant Probability
63%
With Interview (+10.1%)
2y 12m
Median Time to Grant
High
PTA Risk
Based on 650 resolved cases by this examiner. Grant probability derived from career allow rate.

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