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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 23 June 2025 has been entered.
Information Disclosure Statement
The Information Disclosure Statement (lDS) submitted on 26 June 2025 is in compliance with the provisions of 37 CFR 1.97 and has been considered.
Response to Amendment
Claims 1-11 and 13 are currently pending.
Applicant’s amendment, filed 23 June 2025, introduces new limitation(s) not previously considered and therefore overcomes the prior art rejection(s). However, the amendment gives rise to a new ground(s) of rejection under 35 U.S.C. § 103.
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 (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.
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.
Claims 1-2, 5-9 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Fermann (US20160226209A1) in view of Hasegawa (US20190115715A1).
Regarding claim 1, Fermann teaches an optical system (Fig. 6A), comprising:
a dividing element, arranged to divide an input laser beam into a number of spatially separate sub-beams (Fig. 6A, 402; [0076] diffractive element),
at least one optical amplifier, through which the spatially separate sub-beams propagate (Fig. 6A, 403; [0076]),
at least one path-length adjustment element, which is arranged to adjust the path length of at least one of the sub-beams (Fig. 6A, 412; [0079]), and
a combination element arranged to coherently superimpose the sub-beams in an output laser beam ([0079] “second phase plate…for beam combination” output of 406), the combination element arranged shortly before a beam outlet opening of the system or at a location of an application ([0079] “and then to the application”), [1: …].
Fermann does not teach: (1) “wherein at least one optical functional element from the group of a spectral broadening element, an optical isolator, an optical modulator and a pulse compressor is arranged after the at least one optical amplifier in the beam path, through which the spatially separate sub-beams propagate.” However, Hasegawa teaches the limitation in Fig. 4, optical isolator 6c. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the spatially separate amplified sub-beams output of Fermann (Fig. 6A, amplified output from 411), and incorporate the optical isolator as taught by Hasegawa with the motivation to prevent reverse-propagating reflections and unwanted feedback into the amplifier cores, thereby offering improved system stability, reduced noise, and greater signal integrity (see Hasegawa, [0085]).
Regarding claim 2, Fermann in view of Hasegawa teaches the optical system of claim 1, and further teaches: wherein the dividing element and/or the combination element are each formed as diffractive beam splitters (Fermann, Fig. 6A, 402; [0076] diffractive element splitting signal beam to multi-beam pattern).
Regarding claim 5, Fermann in view of Hasegawa the optical system of claim 1, and further teaches: wherein the sub-beams form a two-dimensional array in a plane transverse to the propagation direction (Fermann, Fig. 6A, 403 where each fiber is in a two-dimensional array of a plane transverse to propagation direction; [0076]).
Regarding claim 6, Fermann in view of Hasegawa teaches the optical system of claim 1, and further teaches: wherein provision is made for an error signal detector (Fermann, Fig. 6A, 407; [0079]), which is arranged to derive an error signal (Fermann, [0079] “Phase information for the optical paths corresponding to each individual core within the multicore fiber is obtained”) from the output laser beam or from the sub-beams (Fermann, [0079] “the output beam is directed… onto detector array)”, and a controller, which is arranged to derive from the error signal at least one control signal (Fermann, [0117] “phase controller generating the phase control signals” & “modify an optical phase… in response to a phase control signal”) to control the at least one path-length adjustment element (Fermann, Fig. 6A, Feedback Loop to 412).
Regarding claim 7, Fermann in view of Hasegawa teaches the optical system of claim 1, and further teaches: wherein the at least one optical amplifier is an optically pumped multicore waveguide (Fermann, Fig. 6A, 403 pumped by 409), which is doped with rare earth ions and in which a plurality of waveguide structures is integrated (Fermann, [0063-0067]), wherein each waveguide structure is arranged to carry one of the sub-beams (Fermann, [0076] “concentrate the light… to the location of each individual core of the multi-core amplifier”).
Regarding claim 8, Fermann in view of Hasegawa teaches the optical system of claim 1, and further teaches: wherein the at least one path-length adjustment element is arranged ahead of the at least one optical amplifier in the beam path (Fermann, Fig. 6A, 412 ahead of 403).
Regarding claim 9, Fermann in view of Hasegawa teaches the optical system of claim 1, and further teaches: wherein the combination element is located at a location of an application of the output laser beam (Fermann, [0079] “second phase plate… for beam combination and then to the application”).
Regarding claim 13, Fermann in view of Hasegawa teaches the optical system of claim 1. The referenced embodiment of Fermann does not teach: wherein the at least one path-length adjustment element is located between the dividing element and the at least one optical amplifier. However, Fermann in a separate embodiment teaches the limitation in Fig. 12A, Modulator Array placed after beam is divided but before amplification for adjusting the optical phase path, see [0109]. And further also teaches the limitation in Fig. 1, where modulators 103-105 are placed between splitter 102 and amplifiers 106-108 to adjust each path’s optical path length through phase control, see [0061]. It would have been obvious before the effective filing date of the claimed invention to modify the path-length adjustment element of Fermann in view of Hasegawa with the additional teachings of Fermann in order to perform path-length phase trimming on each channel prior to power amplification, thereby yielding a system with broader applicability across amplifier architectures (Fermann, ¶¶ 89-91, 109-110), fewer components and simplified assembly (Fermann, ¶ 105), easier scaling (Fermann, ¶ 21), and simpler controls (Fermann, ¶¶ 20, 81-84).
Claims 3-4 are rejected under 35 U.S.C. 103 as being unpatentable over Fermann in view of Hasegawa further in view of Klenke (US20170179666A1).
Regarding claim 3, Fermann in view of Hasegawa teaches the optical system of claim 1, however does not teach: wherein the dividing element and/or the combination element are each formed as a reflective element with zones of different reflectivity. Klenke teaches a dividing element formed as a reflective element with zones of different reflectivity in Fig. 2, 1 and a combining element formed as a reflective element with zones of different reflectivity in Fig. 2, 4. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the dividing element and/or the combination element of Fermann in view of Hasegawa with the teachings of Klenke with a reasonable expectation for success since doing so allows for lower optical and thermal coupling to input/output channels, thereby improving thermal management and overcoming power scaling limitations (see Klenke, [0007-0012, 0024]).
Regarding claim 4, Fermann in view of Hasegawa and Klenke teaches the optical system of claim 3, and further teaches: wherein the dividing element and/or the combination element each comprise two or more reflective elements at which the laser radiation is reflected consecutively one or multiple times (Klenke, Fig. 2, elements 1 & 4).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Fermann in view of Hasegawa further in view of Ciu (“Spectral phase effects and control requirements of coherent beam combining for ultrashort ultrahigh intensity laser systems,” published 2016)1.
Regarding claim 10, Fermann in view of Hasegawa teaches the optical system of claim 1, however does not expressly teach: wherein the pulse compressor is an arrangement of one or more grating pairs or prism pairs, wherein each grating or prism pair is penetrated by each of the spatially separate sub-beams single or multiple times. Ciu teaches the limitation in Fig. 2 in which each channel includes a pulse compressor (§2, p. 10126, “compression in every channel”); each compressor implemented as a grating pair or prism pair (§3.C, p. 10129, “grating double, prism double”). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the optical functional element of Fermann in view of Hasegawa to include a pulse compressor for each spatially separate sub-beam as taught by Ciu with the motivation to preventing pulse broadening and peak-power loss (Ciu, §2, p. 10126), thereby yielding a system with greater pulse control and improved beam quality/precision.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Fermann in view of Hasegawa further in view of Peyghambarian (US20090154503A1).
Regarding claim 11, Fermann in view of Hasegawa teaches the optical system of claim 1, however does not expressly teach: wherein the spectral broadening element is a multicore waveguide in which a plurality of waveguide structures is integrated, wherein each waveguide structure carries one of the sub-beams. However, Peyghambarian teaches the limitation in Fig. 3, 48 & 50. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the optical functional element of Fermann in view of Hasegawa to further include the spectral broadening of Peyghambarian with the motivation to reduce optical loss and improve high-power operational stability (see Peyghambarian, [0096]).
Conclusion
Prior art made of record though not relied upon in the present basis of rejection are noted in the attached PTO 892 and include: Schneider (US20130140429A1) which discloses prism pairs corresponding to each beam prior to beam combining. Pan (US5706371A) which discloses an optical isolator which receives multiple spatially separate beams for the optical isolation of each individual channel.
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/ZHENGQING QI/Examiner, Art Unit 3645
1 Cui et al., "Spectral phase effects and control requirements of coherent beam combining for ultrashort ultrahigh intensity laser systems," Appl. Opt. 55, 10124-10132 (2016).