Non-Final Rejection
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This application was filed with claims 1-20, which are pending.
Specification
The disclosure is objected to because of the following informalities: in paragraph [0001] the other application number needs to be updated. Appropriate correction is required.
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 1-18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Yang, Electrical Parasitic Bandwidth Limitations of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers, Dissertation, Univ. of Central Florida (2016) (available at https://stars.library.ucf.edu/etd/5205) (“Yang”).
Regarding claim 1, Yang describes lasers, the entire document discusses VCSELs, and discloses that a total response comprises the parasitic response and the intrinsic response. See section 5.2, page 44 (“When a laser device is driven by a radio frequency electrical source, there are two major limitations to degrade the laser performance. One is the intrinsic laser properties, which are determined by the carrier combination and photon generation speeds. The other is the extrinsic parasitic elements including capacitance and resistance in the circuit.”) (a person skilled in the art would understand this is talking about the same thing as the present invention). Any laser will operate at the operating wavelength, and Yang discusses various lasers at various wavelengths.
Yang does not explicitly say that the wavelength is “selected to maximize the total response of the laser.” However, this is a device claim. The claim defines what the device is. Cf. MPEP 2114 II. The claim does not somehow capture the user’s intent or reasoning behind making the device, her various choices in choosing different materials or why some design was chosen rather than another.
Furthermore, a person of ordinary skill is considered to be aware of all of the prior art. In re Rouffet, 149 F.3d 1350, 1357 (Fed. Cir. 1998) (the law “presumes that all prior art references in the field of the invention are available to this hypothetical skilled artisan.”). The person skilled in the art is therefore aware of Yang, and also of any other references that describe the response of a laser, and any disclosed wavelengths. There is necessarily some maximum response for some workable laser. Yang is clear that the response of a laser is important and therefore is a desirable thing to optimize. Section 5-2 to 5-4. Accordingly, it would have been obvious to a person of ordinary skill in the art to optimize the response by choosing the laser (and associated wavelength) that does so.
Additionally, a person of ordinary skill in the art would understand that selecting a wavelength of a laser affects everything about the laser. Different wavelengths will require different materials, different cavity sizes, different DBRs to ensure appropriate reflectivity, etc. etc. All of these things affect total response, because different materials and sizes etc. will affect both the intrinsic response and the parasitic response. Section 5-2. The total response is going to be understood as important to a person skilled in the art. See section 5.2 p. 44 (it is indication of degradation of performance, thus is important to optimize). The wavelength can therefore be considered a result effective variable that affects the response, and generally it is considered obvious to optimize a result effective variable within prior art conditions. MPEP 2144.05 II. Note that the claims are not attempting to optimize the total response to something that has not been done before, but are optimizing within prior art conditions to the highest possible value.
Additionally, Yang shows the existence of different lasers having different wavelengths and having different total response. See p. 47 Fig. 5-4 (showing different resistance values for different wavelength lasers; from the rest of Yang it is apparent different resistance values will lead to different parasitic response, and thus different total response). At the very least, a person of ordinary skill in the art could look at these lasers and select the one with wavelength having the best total response. The person of ordinary skill could extend this thought process to whatever lasers she knows of, at known wavelengths (and keeping in mind Rouffet above), and select the wavelength corresponding to the best total response.
Regarding claim 2, a person skilled in the art understand that in a VCSEL cavity length determines the operating wavelength of the laser.
Regarding claims 3-6, Yang discloses a parasitic transfer function and an intrinsic transfer function. P. 57 (discussing intrinsic model that is dependent on photon number and slope efficiency); p. 44-45 (parasitic). These functions are dependent on a lot of different variables that may be affected by but are different from the wavelength or cavity length. There therefore may exist some other laser design comprising another cavity or wavelength where these transfer functions have a lower or higher -3 dB frequency as claimed.
Regarding claim 7, the VCSEL is designed in accord with Chapter 2, showing the mirrors are DBRs and have their own thickness and doping profiles. See pp. 12-17. The VCSELs also have an active resistance and capacitance. See section 5.5 starting p. 52, including Table 5-2 p. 56. Yang very much recognizes that resistance and capacitance need to be optimized to improve the parasitic response, p. 52 section 5.5 first par., and again this will be affected by the doping as discussed in section 5.5 and the general VCSEL discussion in section 2.3.
Regarding claim 8, Yang describes a laser, a VCSEL, see Fig. 5-9 p. 53, comprising a first mirror region; a second mirror region; and an active region positioned between the first mirror region and the second mirror region, wherein the active region comprises a cavity defining a cavity length, and wherein the cavity length is a multiple of half an operating wavelength. See Chapters 1-2 for general intro and discussion of VCSELs, including that the cavity is a multiple of half wavelength (p. 2 second sentence).
“wherein the laser has a total response comprising a parasitic response and an intrinsic response; wherein the laser is configured to operate at the operating wavelength; and wherein the operating wavelength is selected to maximize the total response of the laser.” This is all discussed above re: claim 1.
Regarding claim 9, the VCSEL is designed in accord with Chapter 2, showing the mirrors are DBRs and have their own thickness and doping profiles. See pp. 12-17. The VCSELs also have an active resistance and capacitance. See section 5.5 starting p. 52, including Table 5-2 p. 56. Yang very much recognizes that resistance and capacitance need to be optimized to improve the parasitic response, p. 52 section 5.5 first par., and again this will be affected by the doping as discussed in section 5.5 and the general VCSEL discussion in section 2.3.
Regarding claims 10-11, Yang shows VCSELs having active resistance and capacitance within the claimed range. See Table 5-2 p. 56; Fig. 5-9 showing the circuit diagram in the laser.
Regarding claims 12-13, the VCSEL is designed in accord with Chapter 2, showing the mirrors are DBRs and have their own thickness and doping profiles. See pp. 12-17. Again Yang very much recognizes that resistance and capacitance need to be optimized to improve the parasitic response, p. 52 section 5.5 first par., which will also optimize the bandwidth, and again this will be affected by the doping.
Regarding claims 14, the active region is implicitly not doped. See Fig. 2-1 and discussion pp. 8-9 (listing other layers as doped, but not the cavity). The laser of claim 8, wherein the active region is undoped.
Regarding claim 15, the laser comprises an aperture. See Fig. 1 p. 9, under the contact, or Fig. 5-9 p. 53, between H+ regions. The active region comprises a depleted junction under the aperture as it is at a pn junction.
Regarding claim 16, again Yang describes VCSELs throughout.
Regarding claim 17, this method claim is essentially just manufacturing the laser of claim 1, with a wavelength optimizing the total response. The claim is rejected for the same reasons as claim 1, where it was already explained why it would have been obvious to optimize the wavelength and the total response in light of the other teachings of Yang. Note that the claim does not require any steps as to how the wavelength is chosen, therefore the obvious optimization rationale is appropriate. Claim 19 is considered allowable herein because it actually claims steps in how the optimization is to occur, and these steps are not in the prior art.
Regarding claim 18, again the cavity is generally a multiple of half wavelength (p. 2 second sentence), which includes simply one half wavelength within its disclosure.
Regarding claim 20, the VCSEL is designed and eventually manufactured in accord with Chapter 2, showing the mirrors are DBRs and have their own thickness and doping profiles. See pp. 12-17. The VCSELs also have an active resistance and capacitance. See section 5.5 starting p. 52, including Table 5-2 p. 56. Yang very much recognizes that resistance and capacitance need to be optimized to improve the parasitic response, p. 52 section 5.5 first par., and again this will be affected by the doping as discussed in section 5.5 and the general VCSEL discussion in section 2.3.
Claims 1-9, 12-18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Chang et al., Efficient, High-Data Rate…, J. of Selected Topics in Quantum Electronics (2009) (see 8/16/2023 IDS for full cite) (“Chang”).
Regarding claim 1, Chang describes a laser, a VCSEL, see Fig. 4, and the laser has a total response comprising a parasitic response and an intrinsic response. See p. 704, section II. (“For directly current-modulated VCSELs, the bandwidth is determined by the intrinsic laser properties as well as the extrinsic parasitics.”) (a person skilled in the art would understand this is talking about the same thing as the present invention). The laser operates at a wavelength. See abstract.
Chang does not explicitly say that the wavelength is “selected to maximize the total response of the laser.” However, this is a device claim. The claim defines what the device is. Cf. MPEP 2114 II. The claim does not somehow capture the user’s intent or reasoning behind making the device, her various choices in choosing different materials or why some design was chosen rather than another.
Furthermore, a person of ordinary skill is considered to be aware of all of the prior art. In re Rouffet, 149 F.3d 1350, 1357 (Fed. Cir. 1998) (the law “presumes that all prior art references in the field of the invention are available to this hypothetical skilled artisan.”). The person skilled in the art is therefore aware of Chang, and also of any other references that describe the response of a laser (such as those other mentioned in Chang, see below), and any disclosed wavelengths. There is necessarily some maximum response for some workable laser. Chang is clear that the response of a laser is important and therefore is a desirable thing to optimize. Section 5-2 to 5-4. Accordingly, it would have been obvious to a person of ordinary skill in the art to optimize the response by choosing the laser (and associated wavelength) that does so.
Additionally, a person of ordinary skill in the art would understand that selecting a wavelength of a laser affects everything about the laser. Different wavelengths will require different materials, different cavity sizes, different DBRs to ensure appropriate reflectivity, etc. etc. All of these things affect total response, because different materials and sizes etc. will affect both the intrinsic response (see p. 705 section II.A.) and the parasitic response (see pp. 705-706 section II.B.). The total response is going to be understood as important to a person skilled in the art. See sections I-II. The wavelength can therefore be considered a result effective variable that affects the response, and generally it is considered obvious to optimize a result effective variable within prior art conditions. MPEP 2144.05 II. Note that the claims are not attempting to optimize the total response to something that has not been done before, but are optimizing within prior art conditions to the highest possible value.
Additionally, Chang shows the existence of different lasers having different wavelengths and having different total response. See p. 705 Table I (wavelength on left col., total response on right col.). At the very least, a person of ordinary skill in the art could look at these lasers and select the one with wavelength having the best total response. The person of ordinary skill could extend this thought process to whatever lasers she knows of, at known wavelengths (and keeping in mind Rouffet above), and select the wavelength corresponding to the best total response.
Regarding claim 2, a person skilled in the art understands that in a VCSEL cavity length determines the wavelength of the laser.
Regarding claims 3-6, Chang discloses a parasitic transfer function and an intrinsic transfer function. Sections II-A to II-B. These transfer functions are dependent on a lot of different variables that may be affected by but are different from the wavelength or cavity length. There therefore may exist some other laser design comprising another cavity or wavelength where these transfer functions have a lower or higher -3 dB frequency as claimed.
Regarding claim 7, Chang’s laser has an active resistance and capacitance. See Fig. 2 and section II.B. discussion. There is various doping in the device. See section III. Chang very much recognizes that resistance and capacitance need to be optimized to improve the parasitic response, section II.B., and it is known that doping affects the resistance and capacitance of the various layers. parasitic transfer function of the parasitic response of the laser by (i) decreasing the active resistance and (ii) decreasing the active capacitance.
Regarding claim 8, Chang describes a laser, a VCSEL, see Fig. 4, comprising a first mirror region; a second mirror region; and an active region positioned between the first mirror region and the second mirror region, wherein the active region comprises a cavity defining a cavity length, and wherein the cavity length is a multiple of half an operating wavelength. See Fig. 10 (cavity is 490 nm, compared to 980 nm operating wavelength).
“wherein the laser has a total response comprising a parasitic response and an intrinsic response; wherein the laser is configured to operate at the operating wavelength; and wherein the operating wavelength is selected to maximize the total response of the laser.” This is all discussed above re: claim 1.
Regarding claim 9, Chang’s laser has an active resistance and capacitance. See Fig. 2 and section II.B. discussion. There is various doping in the device including the mirrors. See section III. Chang very much recognizes that resistance and capacitance need to be optimized to improve the parasitic response, section II.B., and it is known that doping affects the resistance and capacitance of the various layers.
Regarding claim 12, again the mirrors have various thickness and doping profiles. Section III. Again the doping will affect the parasitics, which will affect the bandwidth, so the doping may be optimized to optimize the parasitics/bandwidth.
Regarding claim 13, the mirrors are DBRs. See p. 707 left col.
Regarding claim 14, the active region is undoped. See Fig. 10 center region.
Regarding claim 15, the laser has an oxide aperture, see Fig. 4. The active region comprises a depleted junction under the aperture as it is at a pn junction.
Regarding claim 16, the laser is a VCSEL. Fig. 4.
.
Regarding claim 17, this method claim is essentially just manufacturing the laser of claim 1, with a wavelength optimizing the total response. The claim is rejected for the same reasons as claim 1, where it was already explained why it would have been obvious to optimize the wavelength and the total response in light of the other teachings of Chang. Note that the claim does not require any steps as to how the wavelength is chosen, therefore the obvious optimization rationale is appropriate. Claim 19 is considered allowable herein because it actually claims steps in how the optimization is to occur, and these steps are not in the prior art.
Regarding claim 18, the laser is manufactured with a cavity length of half the determined operating wavelength. Fig. 10 (cavity is 490 nm, compared to 980 nm operating wavelength).
Regarding claim 20, Chang’s laser has an active resistance and capacitance. See Fig. 2 and section II.B. discussion. There is various doping in the device including the mirrors. See section III. Chang very much recognizes that resistance and capacitance need to be optimized to improve the parasitic response, section II.B., and it is known that doping affects the resistance and capacitance of the various layers.
Allowable Subject Matter
Claim 19 is 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.
There is not taught or disclosed in the prior art a method of manufacturing a laser as in claim 17 including determining an operating wavelength at which the total response as claimed is maximized, wherein the determining step comprises:
determining a parasitic −3 dB frequency of a predicted parasitic transfer function of the predicted parasitic response at a plurality of wavelengths;
determining an intrinsic −3 dB frequency of a predicted intrinsic transfer function of the predicted intrinsic response at the plurality of wavelengths; and
selecting, as the operating wavelength and from the plurality of wavelengths, a wavelength at which a combination of the parasitic −3 dB frequency and the intrinsic −3 dB frequency at the wavelength is greatest.
Conclusion
Some other references are cited that discuss total, intrinsic, and parasitic response.
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/JAMES A MENEFEE/ Primary Examiner, Art Unit 2828