Patents by Inventor Walid A. Atia
Walid A. Atia has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20110051148Abstract: An integrated swept wavelength optical source uses a filtered ASE signal with an optical amplifier and tracking filter. This source comprises a micro optical bench, a source for generating broadband light, a first tunable Fabry Perot filter, installed on the bench, for spectrally filtering the broadband light from the broadband source to generate a narrowband tunable signal, an amplifier, installed on the bench, for amplifying the tunable signal, and a second tunable Fabry Perot filter, installed on the bench, for spectrally filtering the amplified tunable signal from the amplifier. A self-tracking arrangement is also possible where a single tunable filter both generates the narrowband signal and spectrally filters the amplified signal. In some examples, two-stage amplification is provided. The use of a single bench implementation yields a low cost high performance system. For example, polarization control between components is no longer necessary.Type: ApplicationFiled: September 3, 2009Publication date: March 3, 2011Applicant: AXSUN TECHNOLOGIES, INC.Inventors: Dale C. Flanders, Walid A. Atia, Mark E. Kuznetsov
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Patent number: 7671981Abstract: A tunable laser spectroscopic carpet identification system comprises a tunable laser spectroscopy system for generating a tunable signal that is transmitted to a carpet sample. The system detects the tunable signal after interaction with the carpet sample so that an analyzer is able to relate a spectral response of the carpet sample to a chemical composition of the carpet sample. In one example, the spectroscopy system comprises a laser cavity in which the tunable signal is generated, a semiconductor gain medium in the laser cavity, and a tunable element for controlling a wavelength of tunable signal generated in the laser cavity. To deal with variations in water content, the analyzer estimates a water content of the carpet sample using the spectral response of the carpet sample and then determines the chemical composition of the carpet sample in part based on the estimate of the water content.Type: GrantFiled: June 27, 2007Date of Patent: March 2, 2010Assignee: Axsun Technologies, Inc.Inventors: Walid A. Atia, Dale C. Flanders, Robert K. Jenner, Lawrence P. McDermott, Bartley C. Johnson
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Publication number: 20090290167Abstract: A frequency swept laser source for TEFD-OCT imaging includes an integrated clock subsystem on the optical bench with the laser source. The clock subsystem generates frequency clock signals as the optical signal is tuned over the scan band. Preferably the laser source further includes a cavity extender in its optical cavity between a tunable filter and gain medium to increase an optical distance between the tunable filter and the gain medium in order to control the location of laser intensity pattern noise. The laser also include a fiber stub that allows for control over the cavity length while also controlling birefringence in the cavity.Type: ApplicationFiled: March 2, 2009Publication date: November 26, 2009Applicant: AXSUN TECHNOLOGIES, INC.Inventors: Dale C. Flanders, Walid A. Atia, Bartley C. Johnson, Mark E. Kuznetsov, Carlos R. Melendez
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Publication number: 20090059970Abstract: A frequency swept laser source that generates an optical signal that is tuned over a spectral scan band at single discrete wavelengths associated with longitudinal modes of the swept laser source. Laser hopping over discrete single cavity modes allows long laser coherence length even under dynamic very high speed tuning conditions. A ramp drive to the laser is used to linearize laser frequency tuning. A beam splitter is used to divide the optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample. A detector system detects the optical signal from the reference arm and the sample arm for generating depth profiles and images of the sample.Type: ApplicationFiled: February 7, 2008Publication date: March 5, 2009Applicant: AXSUN TECHNOLOGIES, INC.Inventors: Walid A. Atia, Mark E. Kuznetsov, Dale C. Flanders
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Publication number: 20090059971Abstract: A frequency swept laser source that generates an optical signal that is tuned over a spectral scan band at single discrete wavelengths associated with longitudinal modes of the swept laser source. Laser hopping over discrete single cavity modes allows long laser coherence length even under dynamic very high speed tuning conditions. A ramp drive to the laser is used to linearize laser frequency tuning. A beam splitter is used to divide the optical signal between a reference arm leading to a reference reflector and a sample arm leading to a sample. A detector system detects the optical signal from the reference arm and the sample arm for generating depth profiles and images of the sample.Type: ApplicationFiled: February 7, 2008Publication date: March 5, 2009Applicant: AXSUN TECHNOLOGIES, INC.Inventors: Walid A. Atia, Mark E. Kuznetsov, Dale C. Flanders
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Patent number: 7482589Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.Type: GrantFiled: October 18, 2006Date of Patent: January 27, 2009Assignee: Axsun Technologies, Inc.Inventors: Dale C. Flanders, Walid A. Atia, Mark E. Kuznetsov
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Patent number: 7450862Abstract: A detector system for a fiber optic component is insensitive to stray light. Specifically, the invention comprises a detector chip, which converts received light into an electric signal. A baffle substrate is positioned over the detector chip. This baffle substrate has a transmission port through which an optical signal is transmitted to the detector chip. As a result, light that is not directed to be transmitted through the port is blocked by the baffle substrate. In this way, it rejects stray light that may be present in the hermetic package. A detector substrate is provided on which the detector chip is mounted. This detector substrate preferably comprises electrical traces to which the detector chip is electrically connected. The detector substrate can further comprise bond pads for wire bonding to make electrical connections to the electrical traces.Type: GrantFiled: March 19, 2003Date of Patent: November 11, 2008Assignee: Axsun Technologies, Inc.Inventors: Dale C. Flanders, Walid Atia, Eric E. Fitch, Minh Van Le, Randal A. Murdza, Robert L. Payer, Jeffrey A. Korn, Xiaomei Wang, Walter R. Buchwald, L. James Newman, III
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Patent number: 7415049Abstract: An external cavity laser has a mirror-based resonant tunable filter, such as a Fabry Perot tunable filter or Gires-Tournois interferometer tuning element, with the tunable filter being preferably used as a laser cavity mirror. A mirror-based resonant tunable filter is selected in which the spectral response in reflection has an angular dependence. A tilt scheme is used whereby by selecting an appropriate angle between the filter's nominal optical axis and the cavity optical axis, a narrowband peak spectral reflection is provided to the laser cavity. This tunable narrowband spectral reflection from the filter is used to lock and tune the laser output wavelength.Type: GrantFiled: June 22, 2005Date of Patent: August 19, 2008Assignee: Axsun Technologies, Inc.Inventors: Dale C. Flanders, Mark E. Kuznetsov, Walid A. Atia
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Patent number: 7406107Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.Type: GrantFiled: September 29, 2004Date of Patent: July 29, 2008Assignee: Axsun Technologies, Inc.Inventors: Dale C. Flanders, Xinfa Ma, Walid A. Atia
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Patent number: 7375812Abstract: A spectroscopy system comprises a tunable semiconductor laser, such as an external cavity laser, that generates a tunable signal. A detector is provided for detecting the tunable signal after interaction with a sample. In this way, the system is able to determine the spectroscopic response of the sample by tuning the laser of the scan band and monitoring the detector's response. An integrating device, such as an integrating sphere, is interposed optically between the tunable semiconductor laser and the detector. This integrating device is used to mitigate the effects of parasitic spectral noise, such as noise that is generated by speckle or the combination of single-and multi-mode optical fibers in the transmission link between the tunable semiconductor laser and the detector.Type: GrantFiled: February 22, 2005Date of Patent: May 20, 2008Assignee: Axsun Technologies, Inc.Inventors: Walid A. Atia, Dale C. Flanders
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Patent number: 7324569Abstract: A multi semiconductor source tunable spectroscopy system has two or more semiconductor sources for generating tunable optical signals that are tunable over different spectral bands. The system enables the combination of these tunable signals to form an output signal that is tunable over a combined band including these individual spectral bands of the separate semiconductor sources. The system further compensates for spectral roll-off associated with the semiconductor sources. Specifically, near the limits of the semiconductor sources' spectral bands, the power in the tunable signal tends to degrade or decrease. The system compensates for this roll-off using drive current control, attenuators, or electronic compensation.Type: GrantFiled: September 30, 2004Date of Patent: January 29, 2008Assignee: Axsun Technologies, Inc.Inventors: Dale C. Flanders, Walid A. Atia, Mark E. Kuznetsov
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Publication number: 20080019705Abstract: A system includes an optical transmitter that outputs an optical signal having a substantially Gaussian waveform and an optical receiver that is optically coupled to the optical transmitter and has an impulse response essentially matching the waveform. The impulse response and waveform preferably match in the time domain. The transmitter and receiver may be average-power-limited, using, for example, an erbium-doped fiber amplifier. To achieve a high signal-to-noise ratio, the waveform may be designed to minimize jitter, sample duration, matching parasitics, and inter-symbol interference (ISI). Such a waveform may be a return-to-zero (RZ) Gaussian or Gaussian-like waveform and may be transmitted in a variety of modulation formats. Further, the system may be used in WDM or TDM systems. A method for characterizing the time domain impulse response of an optical element used in the optical receiver is provided, where the method is optionally optimized using deconvolution and/or cross-correlation techniques.Type: ApplicationFiled: January 3, 2007Publication date: January 24, 2008Inventors: David Caplan, Walid Atia
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Patent number: 7292344Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.Type: GrantFiled: April 28, 2006Date of Patent: November 6, 2007Assignee: Axsun Technologies, Inc.Inventors: Walid A. Atia, Dale C. Flanders, Petros Kotidis, Mark E. Kuznetsov
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Patent number: 7242509Abstract: Integrated spectroscopy systems are disclosed. In some examples, integrated tunable detectors, using one or multiple Fabry-Perot tunable filters, are provided. Other examples use integrated tunable sources. The tunable source combines one or multiple diodes, such as superluminescent light emitting diodes (SLED), and a Fabry Perot tunable filter or etalon. The advantages associated with the use of the tunable etalon are that it can be small, relatively low power consumption device. For example, newer microelectrical mechanical system (MEMS) implementations of these devices make them the size of a chip. This increases their robustness and also their performance. In some examples, an isolator, amplifier, and/or reference system is further provided integrated.Type: GrantFiled: April 28, 2006Date of Patent: July 10, 2007Assignee: Axsun Technologies, Inc.Inventors: Walid A. Atia, Dale C. Flanders, Petros Kotidis, Mark E. Kuznetsov
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Patent number: 7230710Abstract: A semiconductor source spectroscopy system controls optical power variation of the tunable signal due to polarization dependent loss in the system and thus improves the noise performance of the system. It relies on using polarization control between the source and the sample and/or the sample and the detector. In one example, the source has a semiconductor optical amplifier and an intracavity tunable element for generating a tunable optical signal for illuminating a sample. The tunable optical signal is spectrally tuned over a scan band of the spectroscopy system by operation of the intracavity tunable element.Type: GrantFiled: December 21, 2004Date of Patent: June 12, 2007Assignee: Axsun Technologies, Inc.Inventors: Dale C. Flanders, Walid A. Atia, Mark E. Kuznetsov
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Publication number: 20070071040Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.Type: ApplicationFiled: October 18, 2006Publication date: March 29, 2007Applicant: AXSUN TECHNOLOGIES, INC.Inventors: Dale Flanders, Walid Atia, Mark Kuznetsov
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Patent number: 7181097Abstract: A system includes an optical transmitter that outputs an optical signal having a substantially Gaussian waveform and an optical receiver that is optically coupled to the optical transmitter and has an impulse response essentially matching the waveform. The impulse response and waveform preferably match in the time domain. The transmitter and receiver may be average-power-limited, using, for example, an erbium-doped fiber amplifier. To achieve a high signal-to-noise ratio, the waveform may be designed to minimize jitter, sample duration, matching parasitics, and inter-symbol interference (ISI). Such a waveform may be a return-to-zero (RZ) Gaussian or Gaussian-like waveform and may be transmitted in a variety of modulation formats. Further, the system may be used in WDM or TDM systems. A method for characterizing the time domain impulse response of an optical element used in the optical receiver is provided, where the method is optionally optimized using deconvolution and/or cross-correlation techniques.Type: GrantFiled: March 13, 2002Date of Patent: February 20, 2007Assignee: Massachusetts Institute of TechnologyInventors: David O. Caplan, Walid A. Atia
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Publication number: 20070024847Abstract: A process monitoring system determines a spectral response of a process material. This system has a tunable laser for generating an optical signal that is wavelength tuned over a scan band and an optical probe for conveying the optical signal to the process material and detecting the spectral response of the process material. The optical probe expands a beam of the optical signal to a diameter of greater than 10 millimeters. This avoids one of the difficulties with monitoring these process applications by ensuring that the spectroscopy measurements are accurate and repeatable. It is desirable to sample a relatively large area of the processed material since it can be heterogeneous. Additionally the large area mitigates spectral noise such as from speckle.Type: ApplicationFiled: May 18, 2006Publication date: February 1, 2007Applicant: AXSUN TECHNOLOGIES, INC.Inventors: James Zambuto, Walid Atia, Christopher Cook
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Patent number: 7157712Abstract: An optical power control system for a semiconductor source spectroscopy system controls power fluctuations in the tunable signal from the spectroscopy system and thus improves the noise performance of the system. This general solution has advantages relative to other systems that simply detect reference power levels during the scan and then correct the detected signal after interaction with the sample by reducing the requirements for coordinating the operation of the sample detectors and power or reference detectors. The spectroscopy system comprises a semiconductor source and a tunable filter. The combination of the semiconductor source and tunable signal illuminate a sample with a tunable signal, being tunable over a scan band. The power control system comprises an amplitude detector system for detecting the power of the tunable optical signal and power control system for regulating the amplitude of the tunable optical signal in response to its detected power.Type: GrantFiled: September 29, 2004Date of Patent: January 2, 2007Assignee: Axsun Technologies, Inc.Inventors: Dale C. Flanders, Walid A. Atia, Mark E. Kuznetsov
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Publication number: 20060215713Abstract: An external cavity laser has a mirror-based resonant tunable filter, such as a Fabry Perot tunable filter or Gires-Tournois interferometer tuning element, with the tunable filter being preferably used as a laser cavity mirror. A mirror-based resonant tunable filter is selected in which the spectral response in reflection has an angular dependence. A tilt scheme is used whereby by selecting an appropriate angle between the filter's nominal optical axis and the cavity optical axis, a narrowband peak spectral reflection is provided to the laser cavity. This tunable narrowband spectral reflection from the filter is used to lock and tune the laser output wavelength.Type: ApplicationFiled: June 22, 2005Publication date: September 28, 2006Applicant: Axsun Technologies, Inc.Inventors: Dale Flanders, Mark Kuznetsov, Walid Atia