DETAILED ACTION
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 (i.e., changing from AIA to pre-AIA ) 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.
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 .
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-17 in the reply filed on Jul. 7, 2026 is acknowledged.
Specification
The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification.
Claim Objections
Claim 13 is objected to because of the following informalities: awkwardly worded claim due to extra wording in claim. It appears applicant is attempting to claim “wherein a first stage drawdown ratio is defined by a ratio of first glass cross-sectional area : second glass cross-sectional area, wherein a second stage drawdown ratio is defined by a ratio of second glass cross-sectional area : third glass cross-sectional area, and wherein the first stage drawdown ratio is smaller than the second stage draw down ratio.”. Appropriate correction is required.
Claim Rejections - 35 USC § 112
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.
Claim 7-9 and 16-17 is/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.
In claim 7, lines 2-3, claims a furnace of the optical fibre drawing tower providing the heating, but it is unclear to the Examiner if “the heating” is referencing the heating an end portion of the initial preform, the heating a portion of the intermediate cane, or both heating steps claimed in claim 7. Claims 8-9 depend from claim 7 and is also indefinite.
Claims 16 and 17 claims the fiber is drawn to a membrane thickness between voids, but no membrane is recited in claim 1, and therefore, it is unclear to the Examiner what Applicant is referencing with a membrane thickness. Based on the specification (PGPUB [0035]), a membrane thickness appears to represent a thickness of a glass capillary. Please clarify claims 16 and 17.
Claim Rejections - 35 USC § 103
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, 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.
Claim(s) 1, 6-8, 10-11, and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rosenberger et al. (US 2022/0357506) in view of Tsuji et al. (JP-0986949A – hereinafter Tsuji) and Rosenberger et al. (US 2022/0242773 – hereinafter Pub’773).
Regarding claim 1, Rosenberger (Fig. 1 and [0012]-[0021 ) discloses a method of manufacturing an anti-resonant hollow-core fiber comprising further processing a primary preform (corresponding to an initial preform) into a secondary preform, including a process of elongating the primary preform to form the secondary preform for the hollow-core fiber, ([0093]) the elongating of the primary preform to produce the secondary preform (i.e. cane), and ([0011] and [0115]) drawing the secondary preform to form the hollow-core fiber. Rosenberger (Fig. 1 and [0107]) teaches a primary preform 3 having a transverse cross-sectional structure comprising a hollow core surrounded by a plurality of voids formed by anti-resonant element preforms 4 defining a microstructured cladding, the initial preform (“primary preform 3”) has a first glass cross-sectional area defined by the cladding tube and anti-resonant element preforms, and ([0066]) teaches components of the preform made of quartz glass. Therefore, the method of Rosenberger provides for the step of providing an initial preform, as claimed in lines 2-5 of claim 1.
As discussed above, Rosenberger teaches providing an initial preform with components made of quartz glass and further processing the initial preform into a second preform, such as elongating the primary preform to a secondary preform. Rosenberger ([0048]-[0051]) teaches during elongation the primary preform is continuously supplied to a heating zone at a feed rate, the initial preform softens in the heating zone and ([0093] teaches elongating of the primary preform to form the secondary preform (i.e. cane – corresponding to an intermediate cane), and ([0048]) teaches heating in a heating zone in a vertical drawing process. Rosenberger ([0052]-[0053]) teaches a draw-down ratio during elongation ranging from 1.05 to 10. Accordingly, based on the additional teachings above, Rosenberger teaches the method further comprising elongating (i.e. drawing) of the initial preform comprising heating of the initial preform to form a secondary preform (i.e. cane – corresponding to an intermediate cane) from the softened glass of the initial preform, wherein the intermediate cane has a second glass cross-sectional area less than the first glass cross-sectional due to the draw-down ratio ranging from 1.05 to 10. Additionally, Rosenberger teaches the method comprising heating of the secondary preform (i.e. cane) to draw fiber from the secondary preform, and it would be obvious to a person having ordinary skill in the art, in drawing of the fiber from the intermediate cane comprising drawing from softened glass of the intermediate preform where the hollow core optical fiber has a third glass cross-sectional area less than the second glass cross sectional area, based on the teachings of Rosenberger.
Rosenberger discloses drawing a length of the intermediate cane, but fails to disclose the drawing via a first neckdown. Additionally, Rosenberger discloses heating the intermediate cane to soften the glass to form an optical fiber and therefore, provides for drawing a length of hollow core optical fiber from the intermediate cane, but fails to disclose heating a portion of the intermediate cane spaced from the first neckdown and drawing via a second neckdown. However, Tsuji (abstract and Fig. 1) teaches a method and apparatus that increases efficiency in wire drawing of an optical fiber that includes elongating of an optical fiber base material 1 into an optical fiber base material 2 having a reduced diameter and drawing an optical fiber from optical fiber base material 2. Tsuji (Fig. 1 and pgs. 7-8) illustrates a first heating furnace 7 for heating and melting (i.e. softening) optical fiber preform 1 having a first neckdown to form optical fiber preform 2 and illustrates a second heating furnace 11 for heating and melting (i.e. softening) portion of optical fiber preform 2 spaced from the first neckdown to form a second neckdown and drawing a length of optical fiber 13 from the second neckdown region of the softened portion of optical fiber preform 2. Additionally, Tsuji illustrates the optical fiber preform 1 has an initial cross sectional area and the optical fiber preform 2 has a second cross-sectional area less than the first cross sectional area and the drawn length of optical fiber having a third cross-sectional area less than the second cross sectional area. Additionally, Pub’773 (Fig. 2 and [0143]-[0144]) teaches in the method of elongating, the preform (starting cylinder 4) is fed from above into the heating chamber 3 starting with its lower end and fed at a constant feed rate and softened therein to draw into intermediate-cylinder 12. Both Rosenberger and Tsuji teach elongating an initial optical fiber preform having a first cross-sectional area to a secondary preform (i.e. intermediate cane) having a second cross-sectional area less than the first cross-sectional area by heating and softening and drawing a length of optical fiber having a third cross-sectional area less than the second cross-sectional area by heating and softening the intermediate cane. Additionally, both Rosenberger and Pub’773 teach elongating an optical fiber preform to produce an intermediate cane (i.e. cylinder). Accordingly, based on the additional teachings by Tsuji and Pub’773, it would be obvious to a person having ordinary skill in the art, in the method of Rosenberger, the step of heating the initial preform for elongating including heating and softening the glass at an end portion (i.e. lower end) of the initial preform, and elongating (i.e. drawing), via a first neckdown, to form a length of the intermediate cane and the step of heating a portion of the intermediate cane spaced from the first neckdown for drawing a length of optical fiber including heating and softening the glass at an end of the intermediate cane, via a second neckdown. The combination of Rosenberger, Tsuji, and Pub’773 is merely combining prior art elements according to known methods to yield predictable results for drawing a length of intermediate cane and drawing a length of optical fiber.
Regarding claim 6, in addition to the rejection of claim 1 above, since an optical fiber is drawn from the intermediate cane in the modified method of Rosenberger, it would be obvious to a person having ordinary skill in the art, a length of optical fiber will be formed and separated after drawing the optical fiber from the intermediate cane.
Regarding claim 7, in addition to the rejection of claim 1 above, Tsuji (Fig. 1) illustrates an optical fiber drawing tower comprising a first heating furnace 7 and a second heating furnace 11 for the steps of heating. Therefore, it would be obvious to a person having ordinary skill in the art, the method is performed in an optical fiber drawing tower, a furnace of the optical fiber drawing tower providing heating, as claimed.
Regarding claim 8, in addition to the rejection of claims 1 and 7 above, Tsuji (fig. 1 and pg. 7) discloses a base material feed means and the feeding means moves in the vertical direction. Therefore, based on the additional teachings by Tsuji, it would be obvious to a person having ordinary skill in the art, the modified method of Rosenberger with drawing performed in the optical fiber drawing tower of Tsuji with a feeding means in the vertical direction provides for the drawing of the intermediate cane and drawing the hollow core optical fiber include movement of the initial preform in an axial direction (i.e. vertical direction) towards the furnace in order to provide heating and softening of additional glass.
Regarding claim 10, as discussed in the rejection of claim 1 above, Rosenberger teaches elongating the initial preform with a draw-down ratio ranging from 1.05 to 10 to form the intermediate cane (i.e. secondary preform). Rosenberger ([0108] and Fig. 1) teaches the initial preform having a length of 1000 mm. With a draw-down ratio of 1.05 to 10, it would be obvious to a person having ordinary skill in the art, in the modified method of Rosenberger provides for a length of the secondary preform (i.e. intermediate cane) ranging from 1.05 m to 10m, which overlaps Applicants claimed range of 1 m to 10 m.
Regarding claim 11, in addition to the rejection of claim 1 above, Rosenberger ([0108]) also teaches an outer diameter of the inner cladding tube of 27 mm (27000 microns), which provides for a cross-sectional area of 572,555,261.12 microns squared and (abstract) teaches primary preform diameters ranging from 20 to 70 mm used for the elongation process. Additionally, Rosenberger ([0120]) teaches hollow core fibers having a diameter of 200 microns, which provides for a cross sectional area of 31,416 square microns, and 230 microns, which provides for a cross sectional area of 41,547.56 microns squared. This provides for the claimed overall draw-down ratio of ~18,224 or 13,781, which is within Applicant’s claimed range. Therefore, it would be obvious to a person having ordinary skill in the art, the modified method of Rosenberger provides for drawdown ratios within the range of the claimed drawdown ratio.
Regarding claim 14, in addition to the rejection of claim 1 above, Rosenberger ([0067]) teaches additional sheath material in the form of a cylinder or plurality of cylinders to collapse onto the primary preform, ([0086]) discloses the primary preform consisting of at least one cladding tube, and ([0088]) collapse step. Accordingly based on the additional teachings by Rosenberger, it would be obvious to a person having ordinary skill in the art, in the modified method of Rosenberger further comprising surrounding the initial preform with a cladding tube (i.e. a glass outer layer) before heating the end of the preform, so that the intermediate cane is drawn fused with the glass outer layer, the glass outer layer intended as a jacket for the hollow core optical fiber.
Claim(s) 4-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rosenberger et al. (US 2022/0357506) in view of Tsuji et al. (JP-0986949A – hereinafter Tsuji) and Rosenberger et al. (US 2022/0242773 – hereinafter Pub’773) as applied to claim 1 above, and further in view of Dawes et al. (US 2003/0230118).
Regarding claims 4 and 5, in addition to the rejection of claim 1 above, Rosenberger ([0095]) teaches during elongation the primary preform can also be drawn to have its geometry modified, and ([0058]) teaches individual components of the primary preform and/or secondary preform may be subjected to different internal pressures during elongation or during the fiber drawing process and ([0067]) teaches components of the preform including the anti-resonance element preforms 4, which as discussed in the rejection of claim 1 provides for the voids. Additionally, Dawes (abstract and ) teaches pressures of the sets of holes may be independently controlled to yield a desired hole geometry in the drawn optical fiber. Both Rosenberger and Dawes teaches different pressures during elongation and preforms can be drawn to have geometry modified. Accordingly, with the additional teachings by Rosenberger and Dawes, it would be obvious to a person having ordinary skill in the art, the modified method of Rosenberger further comprising applying one or more pressure to voids formed by the anti-resonance elements in the transverse cross-sectional area of the initial preform during the drawing of the intermediate cane, as claimed in claim 5 and during the drawing of the hollow core optical fiber, as claimed in claim 4, to provide for a modified geometry.
Claim(s) 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rosenberger et al. (US 2022/0357506) in view of Tsuji et al. (JP-0986949A – hereinafter Tsuji) and Rosenberger et al. (US 2022/0242773 – hereinafter Pub’773) as applied to claim 1 above, and further in view of Hesham et al. (“Hollow core optical fibres with comparable attenuation to silica fibres between 600 and 1100 nm”, electronic pub date Nov. 2020).
Regarding claim 16, Rosenberger fails to disclose details of the glass wall thickness (i.e. membrane thickness – see claim interpretation above) between voids in the drawn optical fiber. However, Hesham (Fig. 1 and Table 1) teaches an optical fiber having a similar structure as the optical fiber of Rosenberger. Hesham discloses the with inner and outer capillaries having a thickness in the fiber of 570, 580, 590, 600, 740, 750, 780, 800, 810, and 830 nm. Accordingly, with the similar optical fiber structure (i.e. inner and outer capillaries) disclosed by Rosenberger and Hesham, it would be obvious to a person having ordinary skill in the art, the capillaries (i.e. drawn anti-resonant elements 4) of Rosenberger as having a known prior art capillary thickness, as taught by Hesham. The capillary thicknesses taught by Hesham ranging from 570 nm-830 nm (see Table 1) provides for a membrane thickness between voids in the hollow core optical fiber within Applicant’s claimed range of greater than 200 nm, as claimed.
Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rosenberger et al. (US 2022/0357506) in view of Tsuji et al. (JP-0986949A – hereinafter Tsuji) and Rosenberger et al. (US 2022/0242773 – hereinafter Pub’773) as applied to claim 1 above, and further in view of Uebel et al. (US 2025/0313504 – hereinafter Uebel).
Regarding claim 17, Rosenberger fails to disclose details of the glass wall thickness (i.e. membrane thickness – see claim interpretation above) between voids in the drawn optical fiber. However, Uebel (Fig. 7 and 10 (c)) and [0139] teaches an optical fiber having a similar structure as the optical fiber of Rosenberger where the capillaries have an overall average wall thickness in the fiber of less than 200 nm. Accordingly, with the similar optical fiber structure disclosed by Rosenberger and Uebel, it would be obvious to a person having ordinary skill in the art, the capillaries (i.e. drawn anti-resonant elements 4) of Rosenberger as having a known prior art capillary overall average wall thickness of less than 200 nm, as taught by Uebel. The capillary thickness of less than 200 nm provides for the claimed membrane thickness (i.e. glass wall thickness) between voids in the hollow core optical fiber of 200 nm or less, which is the same range, as claimed in claim 17.
Allowable Subject Matter
Claims 2-3, 12-13, and 15 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims, and fixing any claim objections if applicable.
There are no prior art rejections against Claim 9 but claim 7, from which claim 9 shares dependency, is rejected under 35 U.S.C. 112(b), and allowability of claim 9 will be reconsidered once the 35 U.S.C. 112(b) issues are resolved.
The following is a statement of reasons for the indication of allowable subject matter are discussed below.
Regarding claim 2, the prior art fails to disclose or fairly suggest the combination of the heating steps with the claimed heating a portion of the intermediate cane spaced from the first neckdown and drawing a length of hollow core optical fiber from the softened glass of the intermediate cane, via a second neckdown combined with the method further comprising, after drawing the length of the hollow core optical fiber from the softened glass of the intermediate cane, performing the claimed steps of heating the end portion of the initial preform at or near the first neckdown to soften the glass of the end portion, drawing the intermediate cane of the initial preform in order to restore the length of the intermediate cane, heating the intermediate cane at or near the second neckdown, and drawing a further length of the hollow core optical fiber. Claim 3 depends from claim 2.
Regarding claim 9, the prior art fails to disclose or fairly suggest the method of claim 7 wherein drawing the intermediate cane and drawing the hollow core optical fiber include movement of the initial preform in an axial direction away from the furnace in order to position the intermediate cane in the furnace for heating.
Regarding claim 12, Rosenberger fails to disclose with sufficient the specificity the combination of the claimed first stage drawdown ratio range and the claimed second stage drawdown ratio range.
Regarding claim 13, Rosenberger fails to disclose with sufficient specificity the combination of the claimed first stage drawdown ratio and the claimed second stage drawdown ratio, such that the first stage drawdown ratio is smaller than the second stage drawdown ratio.
Regarding claim 15, the prior art fails to disclose or fairly suggest the method of claim 1, further comprising drawing one or more additional intermediate canes from the intermediate cane before drawing the hollow core optical fiber from a last of the additional intermediate canes, each additional intermediate cane having a glass cross-sectional area less than a glass cross-sectional area of the preceding intermediate cane.
Conclusion
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/LISA L HERRING/ Primary Examiner, Art Unit 1741
