DETAILED ACTION
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 .
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.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 3/27/2026 has been entered.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 20, 22-24, 26, 29-30, and 33-37 are rejected under 35 U.S.C. 103 as being unpatentable over US 2002/0172486 (Fermann) in view of US 20127563 (Farmer).
For claim 20, Fermann discloses a section of an active optical fiber (see Fig.8 with par.24,80-82 and claims 3,6), comprising:
an active core doped with at least one rare-earth element, the active core having a first refractive index and being configured to support a single mode operation of an optical signal (fiber 1, fig. 4a, [0071], [0073]).
Fermann teaches the core may be multimode or single mode and 8 micron cores such as the one in fiber 1 are typically single mode. Further, even if the core of fiber 1 is determined not to be single mode, Farmer teaches single mode cores have advantages such as minimum beam expansion during propagation through free space and optimum focus ability ([0006]), and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to form fiber 1 as a single mode fiber in order to provide minimum beam expansion during propagation through free space and optimum focus ability as taught by Farmer.
Fermann further teaches an inner cladding layer around the active core (fig. 2a and 4a, 1st cladding), the inner
an outer cladding layer around the inner cladding layer, the outer cladding layer having a third refractive index less than the second refractive index (fig. 2a and 4a, 2nd cladding or coating) wherein a birefringence of the active core is less than 10-5 (table 1, fiber 1).
Fermann does not teach a diameter of the active core changes gradually along a length of the section of the active optical fiber forming a tapered longitudinal profile in the embodiment of fiber 1.
However, Farmer does teach a diameter of the active core changes gradually along a length of the section of the active optical fiber forming a tapered longitudinal profile (fig. 1) in order to provide high power while reducing nonlinearities and preserving beam quality ([0012])
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the taper off Farmer with the device of Fermann in order to provide high power while reducing nonlinearities and preserving beam quality.
Farmer further teaches a thickness of the inner cladding layer changes gradually along the tapered longitudinal profile (fig. 1, [0017], [0042]),
wherein a narrow end of the active core is configured to receive the optical signal (fig. 1, 122 and fig. 8, 802, [0060]) and wherein a wide end of the inner cladding layer is configured to receive a pump radiation (fig. 8, 804 and 806, [0018] and [0042]; see also, [0039] and [0042]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the pumping configuration of Farmer as a simple substitution for the pumping configuration of Fermann as the substituted components and their functions were known in the art and the substitution would have yielded predictable results. In the present case, the substituted component provides an alternative pumping configuration. See MPEP 2143 I.B.
For claim 22, Farmer discloses a radius of a first portion of the active core is less than a radius of a second portion of the active core (fig. 1).
For claim 23, Farmer discloses the first portion of the active core satisfies a propagation condition for the single mode operation of the optical signal, and wherein the second portion of the active core supports multimode operation of the optical signal ([0052] and abstract).
For claim 24, Farmer discloses the first portion is single mode ([0052] and abstract) and the known propagation condition for single mode is 2πrNA/λ < 2.405, wherein r is the radius of the first portion the active core, NA is a numerical aperture of the first portion of the active core, and λ is a wavelength of the optical signal ([0006]). It is noted that while Farmer writes the definition of “V” in such a way that it is ambiguous whether 2πr/λ is multiplied by NA or NA is in the denominator, the V-number was well-known to one of ordinary skill in the art before the effective filing date of the claimed invention, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the V-number is (2πr/λ) x NA . Further, the inequality defines the cutoff for single mode so the inequality will be inherently met due to the first portion being single mode.
For claim 26, Farmer teaches the first portion of the active core is configured to receive pump radiation (fig. 7, pumps 704 and 706, [0018], [0038] and [0042]), and/or wherein the second portion of the active core is configured to receive the pump radiation (fig. 8, 804 and 806, [0018], [0039] and [0042]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the pumping configuration of Farmer as a simple substitution for the pumping configuration of Fermann as the substituted components and their functions were known in the art and the substitution would have yielded predictable results. In the present case, the substituted component provides an alternative pumping configuration. See MPEP 2143 I.B.
For claim 29, Farmer teaches a first portion of the inner cladding layer around the first portion of the active core and a second portion of the inner cladding layer around the second portion of the active core, wherein a thickness of the first portion of the inner cladding layer is less than a thickness of the second portion of the inner cladding layer (fig. 1, [0017], [0042]).
For claim 30, Farmer teaches the first portion of the inner cladding layer is configured to receive the pump radiation (fig. 7, pumps 704 and 706, [0018] and [0042]), and/or wherein the second portion of the inner cladding layer is configured to receive the pump radiation (fig. 8, 804 and 806, [0018] and [0042]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the pumping configuration of Farmer as a simple substitution for the pumping configuration of Fermann as the substituted components and their functions were known in the art and the substitution would have yielded predictable results. In the present case, the substituted component provides an alternative pumping configuration. See MPEP 2143 I.B.
For claim 33, Farmer teaches the pump radiation is configured to propagate in a substantially same direction as the optical signal (fig. 7, pumps 704 and 706, [0018] and [0042]) and/or in a substantially opposite direction to the optical signal (fig. 8, 804 and 806, [0018] and [0042]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the pumping configuration of Farmer as a simple substitution for the pumping configuration of Fermann as the substituted components and their functions were known in the art and the substitution would have yielded predictable results. In the present case, the substituted component provides an alternative pumping configuration. See MPEP 2143 I.B.
For claim 34, Farmer teaches at least one pump radiation source (fig. 8, 806 and 804) optically connected to at least one pump radiation coupler (fig. 8, combiner 820), wherein the pump radiation coupler is configured to couple radiation from the pump radiation source to the active optical fiber (fig. 8, 808 704).
For claim 35, Fermann teaches the apparatus comprises a fiber laser device (fig. 8), further comprising: a first reflective mirror optically connected to a first end of the active optical fiber (fig. 8, SA on gold, [0080]).
For claim 36, Fermann teaches a second reflective mirror optically connected to a second end of the active optical fiber or to a second pump radiation coupler optically connected to the second end of the active optical fiber (fig. 8, [0080], right straight cleaved surface of fiber).
For claim 37, Farmer further teaches a fiber master oscillator power amplifier (fig. 7), further comprising: a seed laser source (fig. 7, 702, [0059]) optically connected to the pump coupler (fig. 7, [0705]), wherein the pump coupler is configured to couple light from the seed laser source to the active optical fiber (fig. 7).
Response to Arguments
Applicant's arguments filed 2/24/2026 have been fully considered but they are not persuasive. Applicant substantially argues, see page 6, 2nd full paragraph, that Farmer does not include any indication of the location where the pump radiation is launched, or whether the pump radiation is launched at any end of the tapered fibber from 806 and the description indicates it is launched into the cladding. See [0039] final sentence.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Michael W Carter whose telephone number is (571)270-1872. The examiner can normally be reached M-F, 9:00-5:30.
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/Michael Carter/Primary Examiner, Art Unit 2828