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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 11/30/2023 and 09/04/2025 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the Examiner.
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.
Claim 1 is rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Beddard (US 2024/0066312) in view of Zaho et al. (US 2005/0111785).
Regarding claim 1, Ershov discloses a laser pulser system (Figure 10; [0079] discloses:100, output laser light pulse beam) for an Laser Air Data System (LADS) sensor, comprising:
a Faraday isolator ([0094] discloses: 212, polarizing beam splitter, a quarter wave plate or a Faraday rotator a reflective mirror and 216, output coupler; the beam splitter and quarter wave plate serve to isolate the MO from the amplification stage; Examiner notes that the interchangeability of the quarter wave plate/Faraday rotator is suggested by Ershov and substituting/using the Faraday rotator alternative would have been a predictable use of a known polarization element to perform the same optical routing/isolation function); and
a laser source ([0077] discloses: 22, MO chamber, that supplies a laser output light pulse beam) coupled to the Faraday isolator, the laser source configured to produce a pulsed laser output ([0095] discloses: Faraday switch is activated to allow a laser system output laser pulse beam to be emitted).
Ershov fails to disclose a system having an electro-magnet configured to generate an oscillating magnetic field; a resonant circuit electrically coupled to the electro-magnet and configured to supply a current to the electro-magnet, and allowing the magnetic field of the isolator to oscillate between an “on” and “off” state. Ershov and Beddard are related because both disclose field manipulated systems.
Beddard teaches a system having an electro-magnet ([0006] teaches: pulsed electromagnetic field; Examiner notes that Beddard uses an induction coil configured to emit an ENF pulse, functionally equivalent to an electro-magnet) configured to generate an oscillating magnetic field ([0012] teaches: EMF pulse comprises a decaying sequence of electromagnetic oscillations); a resonant circuit ([0051] teaches: a parallel resonant circuit) electrically coupled to the electro-magnet (Figure 11 depicts: parallel resonant circuit electrically coupled to 26, coil loop inductor, that functions as the electro-magnet) and configured to supply a current to the electro-magnet ([0051] teaches: resonant circuit, powers inductor to a desired current to generate the sequence of electromagnetic oscillations). Ershov and Zhao are related because both disclose Faraday rotators.
Zhao teaches a system allowing the magnetic field of the isolator to oscillate between an “on” and “off” state ([0009] teaches: faraday rotator in combination with a polarizing beam splitter to change the working state of the faraday rotator, allowing full control of which incoming beams are transmitted and which are reflected; transmission through the optical path corresponds to an “on” state and reflection away corresponds to an “off” state).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Beddard and Zhao and provide a system having an electro-magnet configured to generate an oscillating magnetic field; a resonant circuit electrically coupled to the electro-magnet and configured to supply a current to the electro-magnet, and allowing the magnetic field of the isolator to oscillate between an “on” and “off” state. Doing so would provide fast, non-mechanical optical pulse gating using a resonant frequency driven magnetic field controlled faraday switch, thereby improving the overall performance and efficiency of the laser system.
The Applicant is reminded that claim preamble language, a laser pulser system for an Laser Air Data System (LADS) sensor, may not be treated as a limitation where it merely states an intended use of the system and is unnecessary to define the invention. Catalina Marketing Int'l Inc. v. Coolsavings.com, Inc., Fed. Cir., No. 01-1324, 5/8/02. It has been held that a preamble is denied the effect of a limitation where the claim is drawn to a structure and the portion of the claim following the preamble is a self-contained description of the structure not depending for completeness upon the introductory clause. Kropa v. Robie, 88 USPQ 478 (CCPA 1951). Accordingly, the functional claim language including the intended use set forth in the preamble has not been given the same patentable weight as a positively recited feature or structural relationship. Instead the Examiner has applied any prior art thereto by deducing whether the structure disclosed or taught by the reference is capable of performing the functional limitations and the intended use or purpose recited in the preamble, within the overall context of the claim, as applicable.
Claim 2 is rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Beddard (US 2024/0066312) in view of Zaho et al. (US 2005/0111785), as applied to claim 1 above, in view of Guetta et al. (US 2013/0087684).
Regarding claim 2, the modified Ershov discloses the laser pulser system of claim 1.
Ershov fails to disclose a system wherein the Laser Air Data System (LADS) sensor further comprises: a background data collection module configured to collect background light during the off state of the pulsed laser output; and a data processing module configured to subtract the background data from the pulsed laser output data collected during the on state to obtain primary signal data. Ershov and Guetta are related because both disclose optical laser systems.
Guetta teaches a system wherein the Laser Air Data System (LADS) sensor further comprises:
a background data collection module ([0021] teaches: CCD or CMOS having pixels with two charge registers; signal is collected by one charge register while the background is collected equally by both) configured to collect background light during the off state of the pulsed laser output ([0083] teaches: for laser ON situation, the light and background are transferred to one charge register; for the laser OFF intervals, the background only is transferred to another charge register); and
a data processing module configured to subtract the background data from the pulsed laser output data collected during the on state to obtain primary signal data ([0021] teaches: subtracting the two charge registers filters the background from the signal, leaving the reflected laser signals; this model processes the background data during at least the on state).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Guetta and provide a system wherein the Laser Air Data System (LADS) sensor further comprises: a background data collection module configured to collect background light during the off state of the pulsed laser output; and a data processing module configured to subtract the background data from the pulsed laser output data collected during the on state to obtain primary signal data. Doing so would allow for better signal to noise ration and accuracy of the detected primary signal, thereby improving the overall performance and efficiency of the laser pulse system.
Claim 3 is rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Beddard (US 2024/0066312) in view of Zaho et al. (US 2005/0111785), as applied to claim 1 above, in view of Chuang et al. (US 2012/0314286).
Regarding claim 3, the modified Ershov discloses the laser pulser system of claim 1, wherein the system further comprises:
a faraday switch (Zaho: Figure 1 depicts: 106, rotator and 108, polarizing beam splitter; [0009] teaches: Faraday rotator in combination with polarizing beam splitter) configured to transmit or reflect the pulsed laser output using a polarization (Zaho: [0028] teaches: 106, rotator, rotates the state of polarization by +45 or -45 degrees depending on an applied input signal, beams are either horizontally polarized or vertically polarizer after exiting 106, rotator; 108, beam splitter then reflects beams if vertically polarized or allows passage through if beam is horizontally polarized), the Faraday switch comprising:
a first polarizing beam splitter (PBS) (Zaho: [0028] teaches: 108, polarizing beam splitter) configured to transmit the pulsed laser output having an aligned linear polarization (Zaho: [0028] taches: 108, beam splitter allows passage through if beam is horizontally polarized);
the Faraday isolator configured to rotate the linear polarization of the pulsed laser output (Zaho: [0028] teaches: 106, rotator, rotates the state of polarization depending on applied input signal), respective to the on and off states (Zaho: [0009] teaches: faraday rotator in combination with a polarizing beam splitter to change the working state of the faraday rotator, allowing full control of which incoming beams are transmitted and which are reflected; transmission through the optical path corresponds to an “on” state and reflection away corresponds to an “off” state)
Ershov fails to disclose a system with a second PBS configured to at least one of transmit or reflect the pulsed laser output to achieve pulsing of the laser respective at least one of the on and off states. Ershov and Chuang are related because both disclose laser systems.
Chuang teaches a system with a second PBS (Figure 9A depicts: two beam splitters) configured to at least one of transmit or reflect the pulsed laser output to achieve pulsing of the laser respective at least one of the on and off states (in at least abstract teaches: beam splitter transmits the first set of pulses as an output and reflects the second set of pulses into the ring cavity; thus creating output pulse trains from an input laser pulse respective of the on and off states by deciding which light becomes output and which light does not become output).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Chuang and provide a system with a second PBS configured to at least one of transmit or reflect the pulsed laser output to achieve pulsing of the laser respective at least one of the on and off states. Doing so would allow for predictable pulse laser output control, thereby improving the overall efficiency of the laser system.
Claims 4-5 are rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Beddard (US 2024/0066312) in view of Zaho et al. (US 2005/0111785) in view of Chuang et al. (US 2012/0314286), as applied to claim 3 above, in view of Barkauskas et al. (US 2020/0067260).
Regarding claim 4, the modified Ershov discloses the laser pulser system of claim 3.
Ershov fails to disclose wherein the system further comprises: an optical amplifier configured to amplify a pulsed seed laser output, with the Faraday isolator in the off state, having a reflective configuration, wherein the pulsed seed laser output enters and exits through an input port, and the Faraday isolator, positioned along a path of the pulsed seed laser output, rotates the light between the first and the second PBS and directs the pulsed seed laser output away from the optical amplifier. Ershov and Barkauskas are related because both disclose laser systems.
Barkauskas teaches wherein the system further comprises:
an optical amplifier configured to amplify a pulsed seed laser output (Figure 1a depicts: regenerative amplifier including 132, gain medium; [0085] teaches: 112, seed pulse generator; [0023] teaches: injecting a single seed pulse from the master oscillator to an amplifier which undergoes amplification in the gain medium), with the Faraday isolator in the off state ([0098] teaches: regenerative amplifier is in an inactive mode with respect to certain polarization states and a locked mode with respect to another polarization state; [0097] 118, faraday isolator, is in optical path for switching/rotating the polarization state), having a reflective configuration ([0085] teaches: regenerative amplifier cavity is confined between 120 and 122, refractive elements), wherein the pulsed seed laser output enters and exits through an input port (Figure 1a depicts: seed pulse from 112, seed pulse generator entering regenerative amplifier through the optical path associated with 114, first polarization selective element, and the pulse is extracted through the optical path associated with 114, first polarization selective element, which functions as a common input/extraction path), and the Faraday isolator, positioned along a path of the pulsed seed laser output (Figure 1a depicts: 118, Faraday isolator, positioned along the optical path of the laser seed pulse output/extraction path), rotates the light between the first and the second PBS (Figure 1a depicts: pulse traveling through 116, halfwave plate and 118, faraday isolator between 114, first polarization selective element and 128, second polarization-selective element, therefore the rotation happens between 114 and 128) and directs the pulsed seed laser output away from the optical amplifier (Figure 1a depicts: pulse being extracted from amplifier path and directed to 134, output away from the regenerative amplifier cavity).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Barkauskas and provide an optical amplifier configured to amplify a pulsed seed laser output, with the Faraday isolator in the off state, having a reflective configuration, wherein the pulsed seed laser output enters and exits through an input port, and the Faraday isolator, positioned along a path of the pulsed seed laser output, rotates the light between the first and the second PBS and directs the pulsed seed laser output away from the optical amplifier. Doing so would allow for amplification of the pulsed seed laser output and controlled extraction of the pulse away from the optical amplifier, thereby improving overall performance of the laser system.
Regarding claim 5, the modified Ershov discloses the laser pulser system of claim 4, wherein the system further comprises:
the optical amplifier configured to amplify the pulsed laser output in the on state (Barkauskas: [0023] teaches: burst of laser pulses are generated by injecting a single seed pulse from the maser oscillator to an amplifier, then then undergoes amplification in gain medium), the optical amplifier having the reflective configuration (Barkauskas: Figure 1a depicts: regenerative amplifier cavity including 120 and 122, reflective elements), wherein the pulsed laser output enters through the input port and exits through an output port (Barkauskas: Figure 1a depicts: seed pulses entering the regenerative amplifier from 112, seed pulse generator, through the optical path associated with 114, first polarization selective element, and amplified/extracted pulses exiting toward 134, output), and the Faraday isolator is positioned along the pulsed laser output path between the first and the second passes through the optical amplifier (Barkauskas: Figure 1a depicts: 118, faraday isolator positioned in the optical path of the regenerative amplifier between 114 and 128, with the pulse circulating through the reflective regenerative amplifier cavity for multiple passes through 132, gain medium, see abstract for laser pulse trip path; Examiner notes that the same motivation to combine applied to an earlier claim, 4, also applies here, and no further analysis is required, consistent with MPEP § 2143, which permits reliance on previously articulated rationale where the combination and reasonings remain unchanged).
Claims 6-8 are rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Beddard (US 2024/0066312) in view of Zaho et al. (US 2005/0111785) in view of Chuang et al. (US 2012/0314286) in view of Barkauskas et al. (US 2020/0067260), as applied to claim 4 above, in view of Jin et al. (US 6,757,101).
Regarding claim 6, the modified Ershov discloses the laser pulser system of claim 4, wherein the Faraday isolator is configured as a reflective Faraday isolator (Barkauskas: Figure 1a depicts: 118, faraday isolator, positioned in a reflective regenerative amplifier arrangement including 120, 122, reflective elements 114, first polarization selective element, 128, second polarization selective element and 132, gain medium), resulting in a polarization along an S-polarization of the second PBS (Barkauskas: [0095] teaches: 128, second polarizing beam splitter is oriented so that it would transmit/reflect based on polarization), and wherein the second PBS reflects the rotated polarization (Barkauskas: [0095] teaches: 128, second polarizing beam splitter is oriented so that it would transmit/reflect based on polarization; Examiner notes that polarization nomenclature has no effect on function and regardless of which polarization it transmits/reflects; Barkauskas second beam splitter performs the same function), preventing the laser from entering the optical amplifier and preventing seeding of the optical amplifier (Barkauskas: [0098] teaches: that if an s-polarized seed pulse is injected into 124, first branch, it is later transmitted through 128, second polarization selective element without amplification; Examiner notes that the same motivation to combine applied to an earlier claim, 4, also applies here, and no further analysis is required, consistent with MPEP § 2143, which permits reliance on previously articulated rationale where the combination and reasonings remain unchanged).
Ershov fails to disclose a system wherein a magnetic field direction of a Faraday rotator is reversed, causing an input laser to undergo a polarization rotation of 45 degrees after passing through the Faraday rotator. Ershov and Jin are related because both disclose optical systems.
Jin teaches a system wherein a magnetic field direction of a Faraday rotator is reversed, causing an input laser to undergo a polarization rotation of 45 degrees after passing through the Faraday rotator (Col. 7, lines 555-65 teach: rotation of +- 45 degrees by the faraday rotator; Claim 7 teaches: Faraday rotator is reversed by reversing the direction of the magnetic field).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Jin and provide a system wherein a magnetic field direction of a Faraday rotator is reversed, causing an input laser to undergo a polarization rotation of 45 degrees after passing through the Faraday rotator. Doing so would allow for predictable control of the polarization rotation direction by reversing the magnetic field, thereby improving overall beam control and performance.
Regarding claim 7, the modified Ershov discloses the laser pulser system of claim 6, wherein a low-level light produced by the optical amplifier ([0188] discloses: lower level fluorescence of amplification stage) is rotated by the Faraday rotator (Barkauskas: Figure 1a depicts: 132, gain medium producing/amplifying light in the regenerative amplifier path and 118, faraday isolator positioned in the optical path with 116, half wave plate to switch/rotate the polarization state of the pulse, see [0095]) to be reflected by the first PBS (Barkauskas: [0094] teaches: 114, first polarization selective element is oriented to transmit p-polarized seed pulses arriving from the master oscillator side and reflect s-polarized pulses arriving from the opposite side to 134, output; [0095] teaches: the pulse passes through 116, halfwave plate and 118, faraday isolator, which switches the polarization state of the pulse to s-polarization; [0097] teaches: after the pulse is transmitted back toward 114, first polarization selective element its polarization is switched to s-polarization by 118, faraday isolator and 116, halfwave plate, and the pulse is extracted after reflecting off of 114, first polarization selective element), thereby establishing the off state for the reflective Faraday isolator configuration (thus, the rotated light is reflected by 114 to 134, and away from the amplifier, corresponding to the off state of the reflective faraday isolator configuration; Examiner notes that the same motivation to combine applied to an earlier claim, 4, also applies here, and no further analysis is required, consistent with MPEP § 2143, which permits reliance on previously articulated rationale where the combination and reasonings remain unchanged).
Regarding claim 8, the modified Ershov discloses the laser pulser system of claim 7, wherein the off state established by the reflective Faraday isolator is further configured to prevent amplified spontaneous emission (ASE) (in an alternative Ershov [0117] teaches: control of timing to keep ASE below limits; Examiner notes that the system of Ershov is as follows, ASE/low level fluorescence is produce in the amplifier→ faraday isolator/rotator changes the light polarization→ PBS rejects/reflects that polarization during the off state→ that unwanted ASE is routed away from the desired output path so it does not contaminated the output light; this is considered the off state configured to prevent ASE) produced by the optical amplifier from contaminating the output light (Barkauskas; [0094]-[0097] teaches: pulse is switched/rotated by 118, faraday isolator and 116, halfwave plate and 114, first polarization selective element reflects s-polarized light arriving for the opposite side to 134, output; Examiner notes that the same motivation to combine applied to an earlier claim, 4, also applies here, and no further analysis is required, consistent with MPEP § 2143, which permits reliance on previously articulated rationale where the combination and reasonings remain unchanged).
Claim 9 is rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Guetta et al. (US 2013/0087684).
Regarding claim 9, Ershov discloses a sensor, comprising:
a pulsed laser source ([0079] discloses:100, output laser light pulse beam)
Ershov fails to disclose the laser configured to produce a pulsed laser output and oscillate between an “off” state and an “on” state; a background data collection module configured to collect background light during an off state of the pulsed laser output; and a data processing module configured to subtract the background data from the pulsed laser output data collected during the on state to obtain primary signal data. Ershov and Guetta are related because both disclose optical laser systems.
Guetta teaches the laser configured to produce a pulsed laser output and oscillate between an “off” state and an “on” state ([0083] teaches: a laser ON situation where light and background are transferred to one charge register and laser OFF intervals where background only is transferred to another charge register).
a background data collection module ([0021] teaches: CCD or CMOS having pixels with two charge registers; [0083] teaches: that during laser OFF intervals, background only is transferred to another charge registry) configured to collect background light during an off state of the pulsed laser output ([0083] teaches: for laser ON situation, the light and background are transferred to one charge register; for the laser OFF intervals, the background only is transferred to another charge register); and
a data processing module configured to subtract the background data from the pulsed laser output data collected during the on state to obtain primary signal data (Guetta: [0021] teaches: subtracting the two charge registers filters the background from the signal, leaving the reflected laser signals).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Guetta and provide the laser configured to produce a pulsed laser output and oscillate between an “off” state and an “on” state; a background data collection module configured to collect background light during an off state of the pulsed laser output; and a data processing module configured to subtract the background data from the pulsed laser output data collected during the on state to obtain primary signal data. Doing so would allow for better signal to noise ratio and accuracy of the detected primary signal, thereby improving system to noise ratio and accuracy of the detected primary signal.
The Applicant is reminded that claim preamble language, Laser Air Data System (LADS) sensor, may not be treated as a limitation where it merely states an intended use of the system and is unnecessary to define the invention. Catalina Marketing Int'l Inc. v. Coolsavings.com, Inc., Fed. Cir., No. 01-1324, 5/8/02. It has been held that a preamble is denied the effect of a limitation where the claim is drawn to a structure and the portion of the claim following the preamble is a self-contained description of the structure not depending for completeness upon the introductory clause. Kropa v. Robie, 88 USPQ 478 (CCPA 1951). Accordingly, the functional claim language including the intended use set forth in the preamble has not been given the same patentable weight as a positively recited feature or structural relationship. Instead the Examiner has applied any prior art thereto by deducing whether the structure disclosed or taught by the reference is capable of performing the functional limitations and the intended use or purpose recited in the preamble, within the overall context of the claim, as applicable.
Claims 10 and 12-13 are rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Guetta et al. (US 2013/0087684), as applied to claim 9 above, in view of Barkauskas et al. (US 2020/0067260).
Regarding claim 10, the modified Ershov discloses the sensor of claim 9.
Ershov fails to disclose wherein the sensor is coupled to a Faraday isolator. Ershov and Barkauskas are related because both disclose laser systems.
Barkauskas teaches wherein the sensor is coupled to a Faraday isolator (Figure 1a depicts: 118, Faraday isolator, positioned in the optical path of the pulsed/laser amplifier system between 114, first polarization element and 128, second polarization element, such that the laser path is optically coupled to the Faraday isolator).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Barkauskas and provide wherein the sensor is coupled to a Faraday isolator. Doing so would allow for the pulsed laser output to be optically isolated and routed using the Faraday isolator, thereby improving the overall quality of the optical system.
Regarding claim 12, the modified Ershov discloses the sensor of claim 10, further comprising:
an optical amplifier configured in the off state (Barkauskas: Figure 1a depicts: regenerative amplifier including 132, gain medium; [0085] teaches: 112, seed pulse generator; [0023] teaches: injecting a single seed pulse from the master oscillator to an amplifier which undergoes amplification in the gain medium; [0098] teaches: regenerative amplifier is in an inactive mode with respect to certain polarization states and a locked mode with respect to another polarization state; [0097] 118, faraday isolator, is in optical path for switching/rotating the polarization state), the optical amplifier having a reflective configuration (Barkauskas: [0085] teaches: regenerative amplifier cavity is confined between 120 and 122, refractive elements), wherein the pulsed laser output enters and exits through an input port (Barkauskas: Figure 1a depicts: seed pulse from 112, seed pulse generator entering regenerative amplifier through the optical path associated with 114, first polarization selective element, and the pulse is extracted through the optical path associated with 114, first polarization selective element, which functions as a common input/extraction path), and the Faraday isolator is positioned along the pulsed laser output path (Barkauskas: Figure 1a depicts: 118, Faraday isolator, positioned along the optical path of the laser seed pulse output/extraction path) between a first and second pass through the optical amplifier (Barkauskas: Figure 1a depicts: 118, Faraday isolator, positioned between 114, first polarization selective element and 128, second polarization selective element, and the reflective regenerative amplifier cavity provides multiple passes of the pulse through 132, gain medium between 120 and 122 reflective elements; Examiner notes that the same motivation to combine applied to an earlier claim, 10, also applies here, and no further analysis is required, consistent with MPEP § 2143, which permits reliance on previously articulated rationale where the combination and reasonings remain unchanged).
Regarding claim 13, the modified Ershov discloses the sensor of claim 10, further comprising:
the optical amplifier configured to amplify the pulsed laser output in the on state (Barkauskas: [0023] teaches: burst of laser pulses are generated by injecting a single seed pulse from the maser oscillator to an amplifier, then then undergoes amplification in gain medium), the optical amplifier having a reflective configuration (Barkauskas: Figure 1a depicts: regenerative amplifier cavity including 120 and 122, reflective elements), wherein the pulsed laser output enters through the input port and exits through an output port (Barkauskas: Figure 1a depicts: seed pulses entering the regenerative amplifier from 112, seed pulse generator, through the optical path associated with 114, first polarization selective element, and amplified/extracted pulses exiting toward 134, output), and the Faraday isolator is positioned along the pulsed laser output path between the first and the second passes through the optical amplifier (Barkauskas: Figure 1a depicts: 118, faraday isolator positioned in the optical path of the regenerative amplifier between 114 and 128, with the pulse circulating through the reflective regenerative amplifier cavity for multiple passes through 132, gain medium, see abstract for laser pulse trip path; Examiner notes that the same motivation to combine applied to an earlier claim, 10, also applies here, and no further analysis is required, consistent with MPEP § 2143, which permits reliance on previously articulated rationale where the combination and reasonings remain unchanged).
Claim 11 is rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Guetta et al. (US 2013/0087684) in view of Barkauskas et al. (US 2020/0067260), as applied to claim 10 above, in view of Zaho et al. (US 2005/0111785) in view of Chuang et al. (US 2012/0314286).
Regarding claim 11, the modified Ershov discloses the sensor of claim 10.
Ershov fails to disclose a sensor further comprising:
a faraday switch configured to deflect the pulsed laser output using polarization, the Faraday switch comprising: a first polarization beam splitter (PBS) configured to transmit the pulsed laser output having a first linear polarization; the Faraday isolator configured to rotate the polarization of the laser beam; and a second PBS configured to add an additional controlled rotation of the polarization of the pulsed laser output to achieve the on and off states of the pulsed laser source. Ershov and Zhao are related because both disclose Faraday rotators.
Zhao teaches a faraday switch (Figure 1 depicts: 106, rotator and 108, polarizing beam splitter; [0009] teaches: Faraday rotator in combination with polarizing beam splitter) configured to deflect the pulsed laser output using polarization ([0028] teaches: 106, rotator, rotates the state of polarization by +45 or -45 degrees depending on an applied input signal, beams are either horizontally polarized or vertically polarizer after exiting 105, rotator; 108, beam splitter then reflects beams if vertically polarized or allows passage through if beam is horizontally polarized), the Faraday switch comprising:
a first polarization beam splitter (PBS) ([0028] teaches: 108, polarizing beam splitter) configured to transmit the pulsed laser output having an aligned linear polarization ([0028] taches: 108, beam splitter allows passage through if beam is horizontally polarized);
the Faraday isolator configured to rotate the polarization of the laser beam ([0028] teaches: 106, rotator, rotates the state of polarization depending on applied input signal). Ershov and Chuang are related because both disclose laser systems.
Chuang teaches a second PBS (Figure 9A depicts: two beam splitters) configured to add an additional controlled rotation of the polarization of the pulsed laser output to achieve the on and off states of the pulsed laser source (in at least abstract teaches: beam splitter transmits the first set of pulses as an output and reflects the second set of pulses into the ring cavity; thus creating output pulse trains from an input laser pulse respective of the on and off states by deciding which light becomes output and which light does not become output; Zhao teaches that the PBS transmission/reflection is controlled by the polarization state produced by the faraday rotator, such that the transmission corresponds to an on state and reflection/non-output corresponds to an off state, the second PBS provides the additional controlled polarization dependent routing of the already rotated pulsed laser light, thus is considered to add additional controlled rotation of the polarization of the pulsed laser output).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Zhao and Chuang and provide a sensor further comprising: a faraday switch configured to deflect the pulsed laser output using polarization, the Faraday switch comprising: a first polarization beam splitter (PBS) configured to transmit the pulsed laser output having a first linear polarization; the Faraday isolator configured to rotate the polarization of the laser beam; and a second PBS configured to add an additional controlled rotation of the polarization of the pulsed laser output to achieve the on and off states of the pulsed laser source. Doing so would allow for predictable pulse output control, thereby improving the overall efficiency of the laser system.
Claims 14 and 15 are rejected under 35 U.S.C. § 103 as being unpatentable over Ershov et al. (US 2008/0165337) in view of Guetta et al. (US 2013/0087684) in view of Barkauskas et al. (US 2020/0067260), as applied to claim 12 above, in view of Jin et al. (US 6,757,101).
Regarding claim 14, the modified Ershov discloses the sensor of claim 12, wherein the Faraday isolator is configured as a reflective Faraday isolator (Barkauskas: Figure 1a depicts: 118, faraday isolator, positioned in a reflective regenerative amplifier arrangement including 120, 122, reflective elements 114, first polarization selective element, 128, second polarization selective element and 132, gain medium), resulting in a polarization that is reflected by the second PBS (Barkauskas: [0095] teaches: 128, second polarizing beam splitter is oriented so that it would transmit/reflect based on polarization), preventing the laser from entering the optical amplifier (Barkauskas: [0098] teaches: that if an s-polarized seed pulse is injected into 124, first branch, it is later transmitted through 128, second polarization selective element without amplification; Examiner notes that the same motivation to combine applied to an earlier claim, 10, also applies here, and no further analysis is required, consistent with MPEP § 2143, which permits reliance on previously articulated rationale where the combination and reasonings remain unchanged), thereby establishing the off state for the reflective Faraday isolator configuration (Barkauskas: [0098] teaches: that if an s-polarized seed pulse is injected into 124, first branch it is later transmitted through 128, second selective element without amplification; thus the rotated/s-polarized light is routed by 128, second selective element so that it does not seed or enter the gain medium amplification path, corresponding to the off state of the reflective Faraday isolator configuration).
Ershov fails to disclose a sensor wherein a magnetic field direction of a Faraday rotator is reversed, causing a input laser to undergo a polarization rotation of 45 degrees after passing through the Faraday rotator. Ershov and Jin are related because both disclose optical systems.
Jin teaches a sensor wherein a magnetic field direction of a Faraday rotator is reversed, causing an input laser to undergo a polarization rotation of 45 degrees after passing through the Faraday rotator (Col. 7, lines 555-65 teach: rotation of +- 45 degrees by the faraday rotator; Claim 7 teaches: Faraday rotator is reversed by reversing the direction of the magnetic field).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Ershov in view of Jin and provide a sensor wherein a magnetic field direction of a Faraday rotator is reversed, causing an input laser to undergo a polarization rotation of 45 degrees after passing through the Faraday rotator. Doing so would allow for predictable control of the polarization rotation direction by reversing the magnetic field, thereby improving overall beam control and performance.
Regarding claim 15, the modified Ershov discloses the system of claim 14, wherein the off state established by the reflective Faraday isolator is further configured to prevent amplified spontaneous emission (ASE) (in an alternative Ershov [0117] teaches: control of timing to keep ASE below limits; Examiner notes that the system of Ershov is as follows, ASE/low level fluorescence is produce in the amplifier→ faraday isolator/rotator changes the light polarization→ PBS rejects/reflects that polarization during the off state→ that unwanted ASE is routed away from the desired output path so it does not contaminated the output light; this is considered the off state configured to prevent ASE) produced by the optical amplifier from contaminating the output light (Barkauskas; [0094]-[0097] teaches: pulse is switched/rotated by 118, faraday isolator and 116, halfwave plate and 114, first polarization selective element reflects s-polarized light arriving for the opposite side to 134, output; Examiner notes that the same motivation to combine applied to an earlier claim, 4, also applies here, and no further analysis is required, consistent with MPEP § 2143, which permits reliance on previously articulated rationale where the combination and reasonings remain unchanged).
Compact Prosecution
Applicant is advised that the prior art of record generally teaches pulsed laser systems, Faraday rotator/PBS optical switching, resonant coil/electromagnetic field generation, background subtraction during laser-off intervals, and reflective regenerative amplifier routing. However, the prior art does not appear to teach the specific integration of these features in a LADS laser source where the resonant circuit is directly coupled to the electro-magnet of the Faraday isolator such that the Faraday isolator itself is driven between on and off optical states to generate the pulsed laser output.
Accordingly, Applicant may wish to consider amending the independent claims to more clearly require that the laser source provides a continuous or seed laser beam and that the pulsed laser output is generated by the resonant circuit driven electro-magnet of the Faraday isolator, rather than by conventional pulsing of the laser source itself. Applicant may also with to further specify the timing relationship between the Faraday-isolator off state and the background data collection, if such timing is intended to distinguish over ordinary laser-on/laser-off background subtraction systems.
This suggestion is provided for compact prosecution purposes only, any amendment will be considered fully upon entry.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Eul et al. (US 2025/0172828) discloses a Faraday rotator but fails to disclose the correct positioning of elements, Erhard (US 2020/0379281) discloses a laser system with an optical isolator, but fails to disclose the correct placement of beamsplitters
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John Sipes
Examiner
Art Unit 2872
/J.C.S./Examiner, Art Unit 2872
/BUMSUK WON/Supervisory Patent Examiner, Art Unit 2872
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