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 .
Examiner’s Note
The examiner has pointed out particular references contained in the prior art of record within the body of the action for the convenience of the applicant. Although the specified citations are representative of the teachings in the art and are applied to the specific limitations within the individual claim, other passages and figures may apply. Applicant, in preparing response should consider fully the entire reference as potentially teaching all or part of the claimed invention, as well as the context of the passage as taught by the prior art or discussed by the examiner.
In addition, the functional recitation in the claims (e.g. "configured to" or "adapted to" or the like) that does not limit a claim limitation to a particular structure does not limit the scope of the claim. It has been held that the recitation that an element is "adapted to", "configured to", "designed to", or "operable to" perform a function is not a positive limitation but only requires the ability to so perform and may not constitute a limitation in a patentable sense. In re Hutchinson, 69 USPQ 139. (See MPEP 2111.04); see also In In re Giannelli, 739 F.3d 1375, 1378, 109 USPQ2d 1333, 1336 (Fed. Cir. 2014).
Also, it should be noted that it has been held that a recitation with respect to the manner in which a claimed device is intended to be employed does not differentiate the claimed device from a prior art apparatus satisfying the claimed structural limitations Ex-parte Masham 2 USPQ2d 1647 1987).
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.
Claims 10-19 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.
As to claim 10, the limitation, “at least one component and/or a surrounding” is unclear and the relationship between the optical actuator, its settable dispersion, and the controller programmed to carry out claim 1 is not clearly bounded. “Surrounding” is not a well-defined structural term in this context. It is unclear whether this means: ambient environment, housing, surrounding medium, surrounding thermal environment or something else. Also, the use of “and/or” creates ambiguity because it is often considered imprecise unless clearly supported by the specification.
Claims 11-19 are rejected due to their dependencies.
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.
The factual inquiries 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-3, 5, 6, and 10-19 are rejected under 35 U.S.C. 103 as being unpatentable over Brennan, III et al., (hereinafter D1) US 7822347 B1 in view of Calendron Anne-Laure ET al., (hereinafter D2), “Laser system design for table-top X-ray Light source” (all the references cited in the IDS).
As to claim 1, D1 discloses a method for generating output laser pulses (Fig. 5 is a flowchart illustrating a method included in various embodiments of the invention); It further describes generating a pulse, stretching, amplifying, compressing, measuring dispersion, and delivering the pulse), the method comprising: generating input laser pulses having an equal pulse duration (Cols.. 8-10/Figs. 1-5, describes a pulse generator producing a seed pulse and CPA system processing pulses. It states a pulse generator is configured to generate a seed pulse having a certain duration. The overall method in Fig. 5 begins with “Generate Pulse”) , coupling the input laser pulses into an optical actuator ( Figs. 1-4 and col. 8-11, teaches an active tuning element, pulse stretcher, pulse compressor, and modulator within the CPA system. The active tuning element is an optical element whose dispersion is actively adjusted), wherein a dispersion of the optical actuator is settable (Abstract; col. 1-3; Figs. 1-5. D1 expressly states that an active tuning element is incorporated to control overall GVD and that the tuning element can be a stretcher, compressor, modulator, Bragg filter, or chirped light source), and setting the dispersion of the optical actuator for a current input laser pulse ( col. 8-11, teaches dynamic optimization of output using a pulse monitor providing feedback to the active tuning element. Fig. 5 shows tuning steps performed during operation), so that a pulse duration change caused by a change of a temperature of at least one component and/or by a change of an ambient temperature is compensated for (D1 teaches compensation for dispersion variations caused by environmental changes, including the refractive index or air varying with temperature, pressure, and humidity, and variations in system components. This is expressly discussed in the background and Detailed Description) and that an associated output laser pulse has a pulse duration corresponding or nearly corresponding to a target pulse duration (abstract and col. 8-11, teaches optimizing the output pulse width and temporal width of the compressed pulse at the target surface; the pulse monitor measures output characteristics to optimize the pulse duration).
D1 doesn’t explicitly disclose temperature and ambient temperature compensation.
However, D2 is from the same field of endeavor teaches that long optical paths and environmental changes introduce timing drift and that temperature/humidity monitoring and stabilization are required (Section 6.1 Synchronization: thermal expansion of materials causes timing drift, acoustic/thermal noise timing; Section 6.2 Long Term Stability: long term operation requires stabilization against environmental influences; Section 6.3 Controls and diagnostics and 6.4 Cryogenic cooling: monitoring and thermal control are required).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 so that a pulse duration change caused by a change of temperature and/or ambient temperature compensation as suggested by D2 because combining them would have predictably yielded a CPA/laser system with dispersion actively set to maintain pulse duration despite thermal/environmental drift.
As to claim 2, D1 discloses the method as claimed in claim 1, the dispersion of the optical actuator (D1 teaches active tuning based on measurement output characteristics and feedback ) but doesn’t explicitly disclose the dispersion being set for the current input laser is determined based on a current thermal load of the at least one component and on a history of thermal load of the at least one component.
D2 supplies the thermal -load basis for why the tuning is needed. D2 also discloses (Sections 6.2, 6.4 and 6.5) that laser system behavior depends on thermal loading and cryogenic/room-temperature management. Temperature and heating effects influence system operation and further teaches long-term stability, warm-up effects, slow drift, and stabilization over hours; This reflects prior thermal; history influencing current behavior. Section 6.2 and Figs. 9-11 of D2 discusses slow-drift, and long-term output changes.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 by using the known thermal state and thermal history of the system to determine the dispersion setting because the reference teaches that thermal conditions change output timing and stability, the laser system experiences warm-up and drift, long-term operation requires thermal monitoring and stabilization. Using thermal load history to set the dispersion is a predictable control strategy for compensating drift in a high-power ultrafast laser chain.
As to claim 3, D1 discloses feedback from pulse monitor to active tuning element to optimize output pulse characteristics but does not explicitly disclose the method as claimed in claim 2, wherein the current thermal load of the at least one component is determined based on a mean power of the current output laser pulses, and the history of thermal load of the at least one component is determined based on a mean power of respective preceding output laser pulses.
D2 teaches (Sections 6.2, 6.3, and 6.4) energy/power monitoring, long-term operation, and that output power and pulse energy directly affect thermal loading and stability. D2 further describes long-term stability measurements, slow drift over hours, and output energy stability over time (Figs. 9–11), which is consistent with using prior pulse power history as a thermal-history proxy.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 since using mean output power as a proxy for thermal load is an ordinary engineering choice in laser systems because thermal loading is caused by optical power deposition and varies with average power over time. The references teach the need to monitor power/energy and stabilize laser output over time.
As to claim 5, D1 disclose the method as claimed in claim 1, wherein the dispersion of the optical actuator to be set for the current input laser pulse is determined based on last input laser pulses preceding the current input laser pulses (Fig. 5 and col. 8-11; pulse monitor feedback and real-time/periodic tuning based on prior output measurements). D1 doesn’t explicitly teach wherein the last input laser pulses have passed through the at least one component, and/or based on a target dispersion value for a settled state of the at least one component, wherein in the settled state, the temperature of the at least one component is essentially constant over time.
D2 (Section 6.2 Long-term stability and 6.4 Cryogenic cooling) teaches long-term stabilized operating points and thermal steady-state behavior. D2 also expressly discusses stabilization, temperature control, and operation over hours once warm-up is complete.
A feedback controller that uses prior pulse measurements to set the present dispersion value is exactly the kind of closed-loop control taught by D1. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a settled-state target value since this is a predictable and conventional way to initialize or stabilize such a controller, particularly in systems with warm-up drift.
As to claim 6, D1 teaches feedback based tuning of the active tuning element in response to pulse monitor output. D1 also shows in Fig. 5, , the pulse monitor and active tuning element imply feedback correction over successive pulses. However, D1 doesn’t explicitly disclose target dispersion value for settled state.
D2 teaches stable operating points after thermal stabilization.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 by implementing an additive correction scheme based on a steady-state target plus successive pulse corrections since it is an obvious implementations of the feedback loop explicitly taught by D1.
As to claim 10, D1 discloses a laser system for generating output laser pulses (abstract; Figs. 1-5; Detailed Description describing a chirped pulse amplification system with pulse generator, stretcher, amplifier, compressor and output), the laser system comprising: an excitation laser for generating input laser pulses having an equal pulse duration ( D1 discloses a pulse generator 110 producing a seed pulse of a defined duration; Fig. 1l Detailed Description, where the pulse generator is described as generating seed pulse having a certain duration), at least one component and/or a surrounding (This is satisfied by the system’s optical and environmental components, including the stretcher, amplifier, compressor, modulator, pulse monitor, and ambient optical path; Figs. 1-4), an optical actuator arranged between the excitation laser and an output, wherein a dispersion of the optical actuator is settable (D1 expressly teaches an active tuning element is the pulse chain that alters dispersion; abstract” dispersion on the system is tuned by actively tuning one or more components; Figs. 1-4: active tuning element 160/230/310 in the stretcher/compressor/modulator path; Detailed Description: active tuning elements include tunable fiber Bragg gratings, Bragg fibers, modulators, and pulse compressors), and a controller programmed to carry out the method as claimed in claim 1 (D1 teaches feedback control via the pulse monitor providing feedback to the active tuning element. This is a controller-based implementation of the method; Abstract: A pulse monitor is added to the system to measure an output pulse and provide feedback to one or more active tuning elements; Fig. 5: operational method steps showing tuning based on measured output; The controller is implicit in the feedback-based tuning system).
As to claim 11, D1 teaches the laser system as claimed in claim 10, wherein the optical actuator comprises a temperature-controllable stretcher grating for stretching the input laser pulses, or a dispersion changing element arranged in a pulse compressor (D1 teaches tunable stretcher elements, including fiber Bragg gratings and thermal-gradient tuning; Detailed Description: tunable fiber Bragg gratings can be tuned by thermal gradient or strain gradient’ Fig. 1: active tuning element in the stretcher path; In Figs. 2 and 4 as well as in Detailed Description, D1 teaches active tuning elements in the pulse compressor, including dispersion-changing elements).
As to claim 12, D1 discloses the laser system as claimed in claim 10, wherein the optical actuator comprises a movable element of a pulse compressor (D1 teaches a pulse compressor as part of the CPA system, including a Treacy compressor and compressor-side tuning; Fig. 2; Detailed Description describing compressor tuning).
D1 doesn’t explicitly disclose that the movable element being a grating or a prism.
However, D2 discloses compressor architectures and optical pulse-compression elements, including grating-based compressor implementations in ultrafast laser systems. (Section 4.6 and related compressor discussion).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 by having the movable element being a grating or a prism because a POSITA would have used known compressor elements such as grating-based Treacy compressors in D1 system because they are conventional dispersion-control structures in CPA lasers and D2 confirms their use in practical laser system architecture.
As to claim 13, D1 discloses the laser system as claimed in claim 10, wherein the at least one component is an amplifier for amplifying the input laser pulses (D1 expressly teaches a pulse amplifier 130 in the CPA chain; Figs. 1-4; Detailed Description).
As to claim 14, D1 discloses the laser system as claimed in claim 13, but fails to explicitly disclose further comprising a first preamplifier and a second preamplifier arranged upstream of the amplifier.
D2 discloses a multi-stage laser chain with multiple amplifier stages, including frontend and booster/regenerative amplification modules (Sections 4.2-4.7; Tables 4-6; Figs. 12-15).
D1 already teaches an amplifier stage in the pulse chain; D2 Teaches multi-stage amplification architecture. Combining them would have yielded a laser system with one or more preamplifier stages upstream of the main amplifier and thus would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention.
As to claim 15, D1 discloses that the active tuning element is placed in the optical path of the CPA system and may be arranged at the stretcher/compressor stage upstream of amplifications (Figs. 1, 3 and 4) but doesn’t explicitly disclose that wherein the optical actuator is arranged between the excitation laser and the first preamplifier.
D2 teaches front-end architecture with upstream conditioning and distribution before amplification stage (Sections 4.1, 4.2-4.7).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 by locating the dispersion actuator upstream of the first preamplifier since this is a conventional CPA design choice because pulse stretching and phase shaping are typically performed before high-gain amplification to manage pulse energy and nonlinear effects.
As to claim 16, D1 discloses the laser system as claimed in claim 10, but fails to explicitly disclose further comprising a pulse selection unit for letting through selected ones of the input laser pulses, wherein the pulse selection unit is arranged downstream from the excitation laser in a direction of the output.
D2 discloses front-end laser distribution and pulse-selection/delivery architecture for different beamlines and diagnostic paths (Section 4.1; Table 3; Figs. 12-15), thus teaching selecting pulses for downstream use in a laser system.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 by further comprising a pulse selection unit for letting through selected ones of the input laser pulses, wherein the pulse selection unit is arranged downstream from the excitation laser in a direction of the output since pulse selection is a known front-end laser system feature and D2 provides the architecture and motivation for selective routing of pulses downstream from the excitation source.
As to claim 17, D1 discloses the laser system as claimed in claim 10, but fails to explicitly disclose further comprising a nonlinear optical crystal for frequency conversion of the input laser pulses, wherein the nonlinear optical crystal is arranged upstream of the output.
D2 discusses nonlinear optical frequency conversion components in ultrafast laser systems, including harmonic generation and related nonlinear stages (Section 4.6 and the nonlinear-conversion discussion in the system architecture).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 by including a nonlinear optical crystal for frequency conversion of the input laser pulses, wherein the nonlinear optical crystal is arranged upstream of the output because nonlinear frequency conversion is a conventional upstream process in ultrafast laser architecture and D2 supplies the teaching for including such elements in a system like D1’s and would provide predictable result.
As to claim 18, D1 teaches the laser system as claimed in claim 10, further comprising a pulse compressor for compressing the input laser pulses, wherein the pulse compressor is arranged upstream from the output (D1 expressly discloses a pulse compressor 140 (Figs. 1, 2, 4; Detailed Description). Further, arranging the pulse compressor upstream from the out is considered as design choice and thus would have been obvious to obtain predictable result.
As to claim 19, D1 discloses (abstract; Detailed Description) that dispersion can be affected by optical components and environmental conditions, including thermal effects on optical paths and tunable dispersive elements. D2 teaches that laser system performance is affected by heated optical paths, thermal drift, environmental temperature changes, stabilization or components during operation (Sections 6.1-6.4; Figs. 9-11).
The claim merely enumerates component types whose temperature-related behavior affects system performance. D2 strongly supports the notion that both optical and thermally affected non-optical components can influence system stability, and D1 provides the dispersion-compensation mechanism.
As to claim 20, D1 discloses feedback-controlled method using a pulse monitor and active tuning element. A controller or processor executing such steps is the straightforward computer-implemented form of the disclosed method (abstract; Fig. 5; Detailed Description). A non-transitory computer-readable medium having program steps stored thereon, the program steps, when executed by a computer processor, causing performance of the method as claimed in claim 1.
Claims 4, 7, 8, 9 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over D1 in view of D2 and further in view of Benjamin Alonso et al., (hereinafter D3), “Self-calibrating d-scan:measuring ultrashort laser pulses on-target using an arbitrary pulse compressor (all the references cited in the IDS).
As to claim 4, D1 teaches pulse monitor feedback and periodic or real-time tuning. However, D1 doesn’t explicitly disclose the method as claimed in claim 2, wherein the dispersion of the optical actuator to be set is progressively determined from modeling of a pulse phase as a function of the temperature of the at least one component, or is determined beforehand based on a previously known sequence of output laser pulses.
D2 teaches use of diagnostics and long-term measurement history. D3 further teaches iterative numerical optimization of pulse spectral phase and compressor dispersion. The retrieval algorithm uses a model of the phase and iteratively updates it to match measured traces and a phase model and compressor model, which can be extended as an obvious engineering choice to include temperature dependence.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 since D3 specifically teaches an iterative model-based retrieval of phase and compressor dispersion without prior calibration. It would have been obvious to use the same kind of progressive modeling approach to determine the actuator setting based on temperature-dependent phase behavior, because the purpose is the same: compensate unknown/variable dispersion in real time.
As to claim 7, D1 and D2 teaches diagnostics and feedback. Further, precomputed corrections are an obvious extension of those teachings. However, D1 when modified by D2 do not explicitly disclose the method as claimed in claim 6, wherein the correction values are determined progressively from modeling of a pulse phase as a function of the temperature.
D3 teaches iterative phase retrieval using a model and optimization.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 when modified by D2 because the iterative phase-retrieval algorithm in D3 is a clear teaching of progressively determining corrections from a model and measured data. Applying that to temperature-dependent correction values would have been obvious to obtain predictable result.
As to claims 8 and 9, D1 teaches optimizing the output pulse to specified characteristics and using pulse monitor feedback to minimize output variation but doesn’t explicitly disclose wherein a deviation of the pulse duration of the output laser pulses from the target pulse duration is less than 10% or less than 2%.
D3 demonstrates accurate pulse retrieval and optimized compression.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify D1 when modified by D2 wherein a deviation of the pulse duration of the output laser pulses from the target pulse duration is less than 10% or 2% because the numerical threshold is an intended result of feedback-optimized dispersion setting. The prior art teaches controlling pulse width to an optimized target and accurately measuring the result. Maintaining pulse duration within less than 10% or less than 2% of target is an expected result of a feedback-controlled CPA system. It is a routine optimization goal.
As to claim 20, D1 discloses feedback-controlled method using a pulse monitor and active tuning element. A controller or processor executing such steps is the straightforward computer-implemented form of the disclosed method (abstract; Fig. 5; Detailed Description). However, D1 doesn’t explicitly disclose non-transitory computer-readable medium having program steps stored thereon, the program steps, when executed by a computer processor, causing performance of the method as claimed in claim 1.
D3 teaches computational retrieval and optimization of pulse phase/dispersion through algorithmic processing (Abstract; Methods; Results/Discussion).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the feedback and optimization steps in software on an non-transitory computer-readable medium because both D1 and D3 describe computational control/optimization of pulse dispersion and pulse phase and would provide predictable result.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure..
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TARIFUR RASHID CHOWDHURY whose telephone number is (571)272-2287. The examiner can normally be reached M-F: 8 am-5 pm.
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/TARIFUR R CHOWDHURY/Supervisory Patent Examiner, Art Unit 2877
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