The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform

Clauspeter Richter - One of the best experts on this subject based on the ideXlab platform.

  • laser stimulation of auditory neurons effect of shorter pulse duration and penetration depth
    Biophysical Journal, 2008
    Co-Authors: Agnella D Izzo, Joseph T Walsh, Mark Bendett, James E A Webb, Heather A Ralph, Jonathon D Wells, Clauspeter Richter
    Abstract:

    We have pioneered what we believe is a novel method of stimulating cochlear neurons, using pulsed infrared radiation, based on the hypothesis that Optical radiation can provide more spatially selective stimulation of the cochlea than electric current. Very little of the available Optical Parameter space has been used for Optical stimulation of neurons. Here, we use a pulsed diode laser (1.94 μm) to stimulate auditory neurons of the gerbil. Radiant exposures measured at CAP threshold are similar for pulse durations of 5, 10, 30, and 100 μs, but greater for 300-μs-long pulses. There is evidence that water absorption of Optical radiation is a significant factor in Optical stimulation. Heat-transfer-based analysis of the data indicates that potential structures involved in Optical stimulation of cochlear neurons have a dimension on the order of ∼10 μm. The implications of these data could direct further research and design of an Optical cochlear implant.

  • Optical Parameter variability in laser nerve stimulation a study of pulse duration repetition rate and wavelength
    IEEE Transactions on Biomedical Engineering, 2007
    Co-Authors: Agnella D Izzo, Joseph T Walsh, E Jansen, Mark Bendett, James E A Webb, Heather A Ralph, Clauspeter Richter
    Abstract:

    Pulsed lasers can evoke neural activity from motor as well as sensory neurons in vivo. Lasers allow more selective spatial resolution of stimulation than the conventional electrical stimulation. To date, few studies have examined pulsed, mid-infrared laser stimulation of nerves and very little of the available Optical Parameter space has been studied. In this study, a pulsed diode laser, with wavelength between 1.844-1.873 mum, was used to elicit compound action potentials (CAPs) from the auditory system of the gerbil. We found that pulse durations as short as 35 mus elicit a CAP from the cochlea. In addition, repetition rates up to 13Hz can continually stimulate cochlear spiral ganglion cells for extended periods of time. Varying the wavelength and, therefore, the Optical penetration depth, allowed different populations of neurons to be stimulated. The technology of Optical stimulation could significantly improve cochlear implants, which are hampered by a lack of spatial selectivity

Agnella D Izzo - One of the best experts on this subject based on the ideXlab platform.

  • laser stimulation of auditory neurons effect of shorter pulse duration and penetration depth
    Biophysical Journal, 2008
    Co-Authors: Agnella D Izzo, Joseph T Walsh, Mark Bendett, James E A Webb, Heather A Ralph, Jonathon D Wells, Clauspeter Richter
    Abstract:

    We have pioneered what we believe is a novel method of stimulating cochlear neurons, using pulsed infrared radiation, based on the hypothesis that Optical radiation can provide more spatially selective stimulation of the cochlea than electric current. Very little of the available Optical Parameter space has been used for Optical stimulation of neurons. Here, we use a pulsed diode laser (1.94 μm) to stimulate auditory neurons of the gerbil. Radiant exposures measured at CAP threshold are similar for pulse durations of 5, 10, 30, and 100 μs, but greater for 300-μs-long pulses. There is evidence that water absorption of Optical radiation is a significant factor in Optical stimulation. Heat-transfer-based analysis of the data indicates that potential structures involved in Optical stimulation of cochlear neurons have a dimension on the order of ∼10 μm. The implications of these data could direct further research and design of an Optical cochlear implant.

  • Optical Parameter variability in laser nerve stimulation a study of pulse duration repetition rate and wavelength
    IEEE Transactions on Biomedical Engineering, 2007
    Co-Authors: Agnella D Izzo, Joseph T Walsh, E Jansen, Mark Bendett, James E A Webb, Heather A Ralph, Clauspeter Richter
    Abstract:

    Pulsed lasers can evoke neural activity from motor as well as sensory neurons in vivo. Lasers allow more selective spatial resolution of stimulation than the conventional electrical stimulation. To date, few studies have examined pulsed, mid-infrared laser stimulation of nerves and very little of the available Optical Parameter space has been studied. In this study, a pulsed diode laser, with wavelength between 1.844-1.873 mum, was used to elicit compound action potentials (CAPs) from the auditory system of the gerbil. We found that pulse durations as short as 35 mus elicit a CAP from the cochlea. In addition, repetition rates up to 13Hz can continually stimulate cochlear spiral ganglion cells for extended periods of time. Varying the wavelength and, therefore, the Optical penetration depth, allowed different populations of neurons to be stimulated. The technology of Optical stimulation could significantly improve cochlear implants, which are hampered by a lack of spatial selectivity

H M Florez - One of the best experts on this subject based on the ideXlab platform.

  • quantum noise correlations of an Optical parametric oscillator based on a nondegenerate four wave mixing process in hot alkali atoms
    Physical Review Letters, 2020
    Co-Authors: Montana A Guerrero, P Nussenzveig, M Martinelli, Alberto M Marino, H M Florez
    Abstract:

    We present the first measurement of two-mode squeezing between the twin beams produced by a doubly resonant Optical Parameter oscillator (OPO) in an above threshold operation based on parametric amplification by nondegenerate four wave mixing with rubidium (^{85}Rb). We demonstrate a maximum intensity difference squeezing of -2.7  dB (-3.5  dB corrected for losses) with a pump power of 285 mW and an output power of 12 mW for each beam, operating close to the D1 line of Rb atoms. The use of open cavities combined with the high gain media can provide a strong level of noise compression and the access to new operation regimes that could not be explored by crystal based OPOs. The spectral bandwidth of the squeezed light is broadened by the cavity dynamics, and the squeezing level is robust for strong pump powers. Stable operation was obtained up to 4 times above the threshold. Moreover, operation of the OPO close to the atomic resonances of alkali atoms allows a natural integration into quantum networks, including structures such as quantum memories.

  • quantum noise correlations of an Optical parametric oscillator based on a nondegenerate four wave mixing process in hot alkali atoms
    Physical Review Letters, 2020
    Co-Authors: Montana A Guerrero, P Nussenzveig, M Martinelli, Alberto M Marino, H M Florez
    Abstract:

    We present the first measurement of two-mode squeezing between the twin beams produced by a doubly resonant Optical Parameter oscillator (OPO) in an above threshold operation based on parametric amplification by nondegenerate four wave mixing with rubidium ($^{85}\mathrm{Rb}$). We demonstrate a maximum intensity difference squeezing of $\ensuremath{-}2.7\text{ }\text{ }\mathrm{dB}$ ($\ensuremath{-}3.5\text{ }\text{ }\mathrm{dB}$ corrected for losses) with a pump power of 285 mW and an output power of 12 mW for each beam, operating close to the D1 line of Rb atoms. The use of open cavities combined with the high gain media can provide a strong level of noise compression and the access to new operation regimes that could not be explored by crystal based OPOs. The spectral bandwidth of the squeezed light is broadened by the cavity dynamics, and the squeezing level is robust for strong pump powers. Stable operation was obtained up to 4 times above the threshold. Moreover, operation of the OPO close to the atomic resonances of alkali atoms allows a natural integration into quantum networks, including structures such as quantum memories.

Joseph T Walsh - One of the best experts on this subject based on the ideXlab platform.

  • laser stimulation of auditory neurons effect of shorter pulse duration and penetration depth
    Biophysical Journal, 2008
    Co-Authors: Agnella D Izzo, Joseph T Walsh, Mark Bendett, James E A Webb, Heather A Ralph, Jonathon D Wells, Clauspeter Richter
    Abstract:

    We have pioneered what we believe is a novel method of stimulating cochlear neurons, using pulsed infrared radiation, based on the hypothesis that Optical radiation can provide more spatially selective stimulation of the cochlea than electric current. Very little of the available Optical Parameter space has been used for Optical stimulation of neurons. Here, we use a pulsed diode laser (1.94 μm) to stimulate auditory neurons of the gerbil. Radiant exposures measured at CAP threshold are similar for pulse durations of 5, 10, 30, and 100 μs, but greater for 300-μs-long pulses. There is evidence that water absorption of Optical radiation is a significant factor in Optical stimulation. Heat-transfer-based analysis of the data indicates that potential structures involved in Optical stimulation of cochlear neurons have a dimension on the order of ∼10 μm. The implications of these data could direct further research and design of an Optical cochlear implant.

  • Optical Parameter variability in laser nerve stimulation a study of pulse duration repetition rate and wavelength
    IEEE Transactions on Biomedical Engineering, 2007
    Co-Authors: Agnella D Izzo, Joseph T Walsh, E Jansen, Mark Bendett, James E A Webb, Heather A Ralph, Clauspeter Richter
    Abstract:

    Pulsed lasers can evoke neural activity from motor as well as sensory neurons in vivo. Lasers allow more selective spatial resolution of stimulation than the conventional electrical stimulation. To date, few studies have examined pulsed, mid-infrared laser stimulation of nerves and very little of the available Optical Parameter space has been studied. In this study, a pulsed diode laser, with wavelength between 1.844-1.873 mum, was used to elicit compound action potentials (CAPs) from the auditory system of the gerbil. We found that pulse durations as short as 35 mus elicit a CAP from the cochlea. In addition, repetition rates up to 13Hz can continually stimulate cochlear spiral ganglion cells for extended periods of time. Varying the wavelength and, therefore, the Optical penetration depth, allowed different populations of neurons to be stimulated. The technology of Optical stimulation could significantly improve cochlear implants, which are hampered by a lack of spatial selectivity

Mark Bendett - One of the best experts on this subject based on the ideXlab platform.

  • laser stimulation of auditory neurons effect of shorter pulse duration and penetration depth
    Biophysical Journal, 2008
    Co-Authors: Agnella D Izzo, Joseph T Walsh, Mark Bendett, James E A Webb, Heather A Ralph, Jonathon D Wells, Clauspeter Richter
    Abstract:

    We have pioneered what we believe is a novel method of stimulating cochlear neurons, using pulsed infrared radiation, based on the hypothesis that Optical radiation can provide more spatially selective stimulation of the cochlea than electric current. Very little of the available Optical Parameter space has been used for Optical stimulation of neurons. Here, we use a pulsed diode laser (1.94 μm) to stimulate auditory neurons of the gerbil. Radiant exposures measured at CAP threshold are similar for pulse durations of 5, 10, 30, and 100 μs, but greater for 300-μs-long pulses. There is evidence that water absorption of Optical radiation is a significant factor in Optical stimulation. Heat-transfer-based analysis of the data indicates that potential structures involved in Optical stimulation of cochlear neurons have a dimension on the order of ∼10 μm. The implications of these data could direct further research and design of an Optical cochlear implant.

  • Optical Parameter variability in laser nerve stimulation a study of pulse duration repetition rate and wavelength
    IEEE Transactions on Biomedical Engineering, 2007
    Co-Authors: Agnella D Izzo, Joseph T Walsh, E Jansen, Mark Bendett, James E A Webb, Heather A Ralph, Clauspeter Richter
    Abstract:

    Pulsed lasers can evoke neural activity from motor as well as sensory neurons in vivo. Lasers allow more selective spatial resolution of stimulation than the conventional electrical stimulation. To date, few studies have examined pulsed, mid-infrared laser stimulation of nerves and very little of the available Optical Parameter space has been studied. In this study, a pulsed diode laser, with wavelength between 1.844-1.873 mum, was used to elicit compound action potentials (CAPs) from the auditory system of the gerbil. We found that pulse durations as short as 35 mus elicit a CAP from the cochlea. In addition, repetition rates up to 13Hz can continually stimulate cochlear spiral ganglion cells for extended periods of time. Varying the wavelength and, therefore, the Optical penetration depth, allowed different populations of neurons to be stimulated. The technology of Optical stimulation could significantly improve cochlear implants, which are hampered by a lack of spatial selectivity