Final Rejection
This application was filed with claims 1-14. Following a non-final action, applicant filed an amendment on 1/8/2026 (“Response”) in which the specification and claims 1 and 2 are amended. Claims 1-14 are pending.
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.
Claims 1-3 and 7-12 are rejected under 35 U.S.C. 103 as being unpatentable over US 2017/0256904 to Aspelmeyer et al. (“Aspelmeyer”) in view of US 2018/0191121 to Schad et al. (“Schad”), and further in view of US 2020/0094487 to Wahl et al. (“Wahl”).
Aspelmeyer discloses a monolithic laser amplification module for a solid-state laser system (Figs. 1,2; par. [0022]-[0028],[0047]-[0064]) comprising
a solid-state disk 1A (Fig. 2; par. 49,57,58; 03 discloses for example a Nd:YAG disk);
a monolithic composite comprising a heat sink 5 and a reflecting coating 1S configured to at least partially reflect an incident beam propagated in the solid state disk in a wavelength range from 200 nm - 10 μm (Fig. 2; par. [0019], [0024], [0049], [0057]-[0061] discloses for example a diamond heat sink and a Nd:YAG, i.e. emission and reflection around 1064 nm), wherein the reflecting coating 1S is deposited on surface of the heat sink 5 by a deposition method (par. [0058]), wherein the heat sink has:
transverse thermal conductivity at least 100 W/m K (par. [0024], Table 1 discloses a diamond heat sink, i.e. a thermal conductivity of about 2000 W/mK),
Young's modulus at least 100 GPa, preferably at least 300 GPa (par. [0024], Table 1 discloses a diamond heat sink, i.e. a modulus of about 1050 GPa); and wherein
the solid-state disk and the monolithic composite have surfaces having peak to valley flatness and have a surface roughness RMS< 2 nm (par. [0052],[0062] discloses a RMS of less than 1 nm); and wherein
the surfaces of the solid-state disk and the monolithic composite are directly and permanently bonded together (par. [0061]).
Aspelmeyer does not disclose any thickness of the heat sink so does not disclose a thickness of the heat sink at least 1 mm. Schad teaches that it was known for a laser disk to be bonded on a diamond heat sink, much like Aspelmeyer. [0003], [0032]-[0034], [0069]. The heat sink may be 0.75 to 7 mm thick, which falls within the claimed range. [0032]. It would have been obvious to a person of ordinary skill in the art to choose such a thickness as a use of a known technique to improve similar devices in the same way. MPEP 2143 I.C. Aspelmeyer is a base device that differs from the claim by not specifying the thickness of the heat sink. Schad is a comparable device that does include such thickness as claimed. A person of ordinary skill could have implemented this known technique in Aspelmeyer with predictable results. The skilled artisan would need to choose some thickness for the heat sink, therefore it is reasonable to look to similar devices such as Schad, and in light of Schad’s disclosure the person skilled in the art would recognize that 0.75 to 7 mm would be reasonable values that will permit the laser to operate in a normal and predictable manner.
Aspelmeyer does not give any value for flatness of the disk and composite. Aspelmeyer discloses already to provide bonding surfaces with a RMS of less than 1 nm (par. [0062]) and a direct bonding between two surfaces without any intermediate glue or solder (par. [0061]). In order to put the teaching of Aspelmeyer into practice the skilled person has to look for a teaching about which surface quality is needed for permanent bonding of crystalline surfaces. Therefore, he will consider Wahl as relevant. Wahl discloses for permanent bonding of two crystalline surfaces (Figs. 1-5; par. [0014]-[0039]) the surfaces should have a surface flatness of less than λ/10 (par. [0033]) and a RMS of less than 1 nm (par. [0034]). It would have been obvious to a person of ordinary skill in the art to use such values for flatnesss as Wahl teaches that they provide good contacting for a good bond. [0032]. While this is not the same exact disclosure of flatness as claimed, it overlaps with the claimed range and therefore is prima facie obvious. MPEP 2144.05 I.
Regarding clam 2, Aspelmeyer does not disclose that the module has a thermal conductivity of >0.1 W/(m K) for solid-state disk temperatures <500° C. caused by laser operation. However Aspelmeyer’s device is made of the same materials as those of the present invention and has the same general structure. The specification does not explain how these properties are to occur, therefore it is considered that this is simply the property of the module based on the general structure and materials. Since Aspelmeyer has the same general structure and materials the claimed properties are deemed inherent. MPEP 2112.01 I-II.
Regarding claim 3, the reflector 1S may be a thin film stack of a plurality of alternating layers forming the reflective coating, wherein layers are made of materials having alternating refractive indexes and wherein the top layer is bonded to the solid-state disk. [0058].
Regarding claims 7 and 9, Aspelmeyer discloses that the heat sink may be curved. [0061]. The flatness and roughness values of claim 9 are already shown as to claim 1.
Regarding claim 8, the flatness and roughness are taught as in the rejection of claim 1. While claim 8 is a bit more limiting, the values in the art still overlap with these claimed values and therefore the claimed values are obvious. MPEP 2144.05 I.
Regarding claim 10, Aspelmeyer uses these types of materials for the gain medium. [0019].
Regarding claims 11-12, Aspelmeyer uses these same materials for the heat sink, with transparencies as claimed. [0023]-[0025]; Table 1. While the attenuation coefficient is not given, the heat sink is said to be transparent. Also the same materials are used so this claimed property is presumed inherent. MPEP 2112.01 I-II.
Claims 4-6 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Aspelmeyer, Schad, and Wahl, as applied to claim 1, and further in view of Rantamaki et al., Proc. of SPIE March 2015 (see 12/15/2022 IDS) (“Rantamaki”).
Regarding claims 4 and 6, Aspelmeyer does not show a sacrificial layer on top of the reflective coating that decreases the reflectivity of the coating less than 10% or the sacrificial layer comprises a plurality of layers forming a film stack, wherein this film stack is configured to increase the laser-induced damage threshold of the module. Rantamaki describes a similar optically pumped disk laser on diamond heatsink with a thin film stack as the reflective layer, and also includes additional layer of Al2O3 and Al that may be considered sacrificial layer. See Fig. 4(a). It would have been obvious to a person of ordinary skill in the art to add these layers as they allow for similar reflectivity but allow the use of fewer reflector layers. See p. 934908-7. The reflector is still at over 99% reflectivity so it decreases reflectivity less than 10% as claimed. P. 934908-7. As to laser induced damage threshold, Al2O3 will be protective and will reduce this at least to some extent. Furthermore, the present invention also uses Al2O3 as the sacrificial layer, so the examiner maintains that because it is the same structure the claimed property is presumed inherent. See MPEP 2112.01 I-II.
Regarding claim 5, Aspelmeyer and Rantamaki show sacrificial layers that may be a plurality of layers as above. They do not show at least one sacrificial layer is structured by micro or nano-pattern increasing mechanical and/or thermal properties of the solid-state disk. Wahl teaches that the layers for bonding may be micro patterned. [0025]-[0027]. It would have been obvious to a person of ordinary skill in the art to do this as it allows an escape route for entrapped gases or the like occurring during the bonding process, as taught by Wahl.
Regarding claim 13, Aspelmeyer does not show an AR coating on the surface opposite to where the gain medium is bonded as claimed. Rantamaki describes a similar optically pumped disk laser on diamond heatsink, with an AR coating applied on the top of the gain medium opposite the side where it is bonded to the heatsink. Fig. 3(a); 934908-5. It would have been obvious to a person of ordinary skill in the art to include such a coating as it reduces the reflectivity at the top where the pump signal is coming in, which a person of ordinary skill would recognize would improve the device by allowing more pump light to enter.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Aspelmeyer, Schad, and Wahl as applied to claim 1, and further in view of US 2014/0307305 to Deri et al. (“Deri”).
Regarding claim 14, claim 1 is taught as above, but it is not disclosed that the edges are roughened or beveled. Deri teaches that a solid state laser gain medium might have beveled edges to reduce parasitic lasing and ASE. [0034]. It would have been obvious to a person of ordinary skill in the art to include such edges for this reason.
Response to Arguments
The arguments filed with the Response have been fully considered.
The specification objection and the 112 rejection are withdrawn in light of applicant’s amendment, which corrected the issues noted previously.
As to the art rejections, applicant argues that Aspelmeyer does not disclose a reflecting coating deposited on a heat sink as claimed, as the cited par. [0058] does not mention bonding the reflecting coating to a heat sink. Applicant further argues that par. [0060] of Aspelmeyer proves this point. Par. [0060] states that “The laser optical gain material 1 of the laser active medium 2 as shown in FIG. 2 is bonded onto a heat sink 5. This bond is a direct bond 3.” Thus, applicant argues that the gain material is bonded to the heat sink, not the reflecting coating.
First, [0058] was cited primarily to show that reflecting coating 1S may be deposited by a deposition method as claimed. This paragraph of the rejection, discussing the heat sink 5 and reflecting coating 1S, also cited Fig. 2 and various other paragraphs, including [0057]-[0061]. These paragraphs and Fig. 2 (reproduced below) make clear that it is in fact 1S that is bonded to the heat sink. While par. [0060] does say that element 1 is bonded to the heat sink, this must be taken in context, which shows that the reflective stack 1S is part of the laser gain material 1. [0059] states that “In FIG. 2, one side of the laser optical gain material 1 corresponds to the semiconductor structure 1A, the other side corresponds to the high reflectivity stack 1S.” So 1S is just one side of 1. And Fig. 2 quite plainly shows element 1S as part of element 1; 1 has a curly bracket showing it includes both 1A and 1S, just as [0059] says, and 1S is bonded to the heat sink 5.
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The examiner fails to see how Aspelmeyer does not disclose reflector 1S bonded to heat sink 5. The arguments are not persuasive. Applicant further states that Schad and Wahl do not remedy this deficiency, but the examiner maintains that Aspelmeyer is not in fact deficient.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to James Menefee whose telephone number is (571)272-1944. The examiner can normally be reached M-F 7-4.
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/JAMES A MENEFEE/ Primary Examiner, Art Unit 2828