Brendan McGuckin | Edinburgh Napier University (original) (raw)
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Papers by Brendan McGuckin
Solid State Lasers III, 1992
Tunable continuous-wave and pulsed laser output was obtained from a Tm-sensitized Ho:YLiF4 crysta... more Tunable continuous-wave and pulsed laser output was obtained from a Tm-sensitized Ho:YLiF4 crystal at subambient temperatures when longitudinally pumped with a diode laser array. A conversion efficiency of 42 percent and slope efficiency of approximately 60 percent relative to the absorbed pumped power have been achieved at a crystal temperature of 275 K. The emission spectrum was etalon tunable over
The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onb... more The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onboard radiometric calibration of the multiangle imaging spectroradiometer, at laser wavelengths of 442, 632.8, and 859.9 nm. With p-and s-polarized incident light and for an angle of incidence of 45°, the bidirectional reflectance distribution function was measured over a polar angle range of 1-85°and a range of azimuthal angles of 0 -180°in 10°increments. The resultant directional-hemispherical reflectance is found by integration to be 1.00 Ϯ 0.01 at 442 nm, 0.953 Ϯ 0.01 at 632.8 nm, and 0.956 Ϯ 0.01 at 859.9 nm. The experimental methodology and the data analysis are presented together with a full discussion of the primary experimental errors.
Applied Optics - APPL OPT, 1999
The Multiangle Imaging Spectroradiometer makes use of an onboard calibration system that includes... more The Multiangle Imaging Spectroradiometer makes use of an onboard calibration system that includes two Spectralon panels that are used to reflect sunlight into the cameras. During preflight testing, these panels were quantified in terms of their bidirectional reflectance distribution function, which was measured as a function of the source-incident and detector view angles and at laser wavelengths of 442.0, 632.8, and 859.9 nm. Principal plane measurements are presented in which polarizations of the source and detector are analyzed. These data are unique and valuable in modeling Spectralon reflectance properties and for experiments in which polarization sensitivities are important.
Applied Optics, 1993
A diode-laser-pumped single-frequency thulium holmium yttrium lithium fluoride laser that exhibit... more A diode-laser-pumped single-frequency thulium holmium yttrium lithium fluoride laser that exhibits a closed-loop stability of a few megahertz and a continuous single-mode tuning range of 800 MHz is described. The laser output power is 25 mW and is tunable over ~ 8 cm(-1) at 25 degrees C.
Applied Optics, 1997
The reflectance properties of an engineering model ͑EM͒ of the Spectralon panel intended for use ... more The reflectance properties of an engineering model ͑EM͒ of the Spectralon panel intended for use within an on-board calibrator ͑OBC͒ on the NASA Multiangle Imaging Spectroradiometer ͑MISR͒ instrument have been fully characterized with regard to panel uniformity and isotropy in response to three incident laser wavelengths of 442, 632.8, and 859.9 nm. A regional variation in the relative bidirectional reflectance factor ͑RBRF͒ across the surface of the EM panel, which contributes to spatial nonuniformity at the Ϯ2% level, has been measured at all three laser wavelengths. Further, a reflectance anisotropy has been identified. The mechanism causing these departures from the ideal Lambertian surface may originate in the sanding of the Spectralon surface in the final stage of preparation. This supposition is corroborated by measurements made on a pressed polytetrafluoroethylene ͑PTFE͒ panel in which a greatly reduced anisotropy in panel RBRF is measured. The EM panel RBRF exhibits a deviation from Lambertian characteristics as an off-specular peak in the forward scattering direction. A common crossover point at an angle of reflection of ϳ37°at which the BRF is constant within Ϯ0.4% for an illumination angle range of i ϭ 30°-60°is observed at all three wavelengths. Two Spectralon protoflight panels that were fabricated after the EM was studied were also the subject of a uniformity study over part of the area of the Spectralon panels at the 442-nm wavelength. The analysis indicated that the panel uniformity satisfies the Ϯ0.5% criterion, which indicates improved panel preparation. However, the off-specular peak in the forward scattering direction was essentially unchanged, with the crossover point at ϳ37°.
Applied Optics, 1998
The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onb... more The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onboard radiometric calibration of the multiangle imaging spectroradiometer, at laser wavelengths of 442, 632.8, and 859.9 nm. With p-and s-polarized incident light and for an angle of incidence of 45°, the bidirectional reflectance distribution function was measured over a polar angle range of 1-85°and a range of azimuthal angles of 0 -180°in 10°increments. The resultant directional-hemispherical reflectance is found by integration to be 1.00 Ϯ 0.01 at 442 nm, 0.953 Ϯ 0.01 at 632.8 nm, and 0.956 Ϯ 0.01 at 859.9 nm. The experimental methodology and the data analysis are presented together with a full discussion of the primary experimental errors.
Solid State Lasers III, 1992
Tunable continuous-wave and pulsed laser output was obtained from a Tm-sensitized Ho:YLiF4 crysta... more Tunable continuous-wave and pulsed laser output was obtained from a Tm-sensitized Ho:YLiF4 crystal at subambient temperatures when longitudinally pumped with a diode laser array. A conversion efficiency of 42 percent and slope efficiency of approximately 60 percent relative to the absorbed pumped power have been achieved at a crystal temperature of 275 K. The emission spectrum was etalon tunable over
The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onb... more The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onboard radiometric calibration of the multiangle imaging spectroradiometer, at laser wavelengths of 442, 632.8, and 859.9 nm. With p-and s-polarized incident light and for an angle of incidence of 45°, the bidirectional reflectance distribution function was measured over a polar angle range of 1-85°and a range of azimuthal angles of 0 -180°in 10°increments. The resultant directional-hemispherical reflectance is found by integration to be 1.00 Ϯ 0.01 at 442 nm, 0.953 Ϯ 0.01 at 632.8 nm, and 0.956 Ϯ 0.01 at 859.9 nm. The experimental methodology and the data analysis are presented together with a full discussion of the primary experimental errors.
Applied Optics - APPL OPT, 1999
The Multiangle Imaging Spectroradiometer makes use of an onboard calibration system that includes... more The Multiangle Imaging Spectroradiometer makes use of an onboard calibration system that includes two Spectralon panels that are used to reflect sunlight into the cameras. During preflight testing, these panels were quantified in terms of their bidirectional reflectance distribution function, which was measured as a function of the source-incident and detector view angles and at laser wavelengths of 442.0, 632.8, and 859.9 nm. Principal plane measurements are presented in which polarizations of the source and detector are analyzed. These data are unique and valuable in modeling Spectralon reflectance properties and for experiments in which polarization sensitivities are important.
Applied Optics, 1993
A diode-laser-pumped single-frequency thulium holmium yttrium lithium fluoride laser that exhibit... more A diode-laser-pumped single-frequency thulium holmium yttrium lithium fluoride laser that exhibits a closed-loop stability of a few megahertz and a continuous single-mode tuning range of 800 MHz is described. The laser output power is 25 mW and is tunable over ~ 8 cm(-1) at 25 degrees C.
Applied Optics, 1997
The reflectance properties of an engineering model ͑EM͒ of the Spectralon panel intended for use ... more The reflectance properties of an engineering model ͑EM͒ of the Spectralon panel intended for use within an on-board calibrator ͑OBC͒ on the NASA Multiangle Imaging Spectroradiometer ͑MISR͒ instrument have been fully characterized with regard to panel uniformity and isotropy in response to three incident laser wavelengths of 442, 632.8, and 859.9 nm. A regional variation in the relative bidirectional reflectance factor ͑RBRF͒ across the surface of the EM panel, which contributes to spatial nonuniformity at the Ϯ2% level, has been measured at all three laser wavelengths. Further, a reflectance anisotropy has been identified. The mechanism causing these departures from the ideal Lambertian surface may originate in the sanding of the Spectralon surface in the final stage of preparation. This supposition is corroborated by measurements made on a pressed polytetrafluoroethylene ͑PTFE͒ panel in which a greatly reduced anisotropy in panel RBRF is measured. The EM panel RBRF exhibits a deviation from Lambertian characteristics as an off-specular peak in the forward scattering direction. A common crossover point at an angle of reflection of ϳ37°at which the BRF is constant within Ϯ0.4% for an illumination angle range of i ϭ 30°-60°is observed at all three wavelengths. Two Spectralon protoflight panels that were fabricated after the EM was studied were also the subject of a uniformity study over part of the area of the Spectralon panels at the 442-nm wavelength. The analysis indicated that the panel uniformity satisfies the Ϯ0.5% criterion, which indicates improved panel preparation. However, the off-specular peak in the forward scattering direction was essentially unchanged, with the crossover point at ϳ37°.
Applied Optics, 1998
The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onb... more The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onboard radiometric calibration of the multiangle imaging spectroradiometer, at laser wavelengths of 442, 632.8, and 859.9 nm. With p-and s-polarized incident light and for an angle of incidence of 45°, the bidirectional reflectance distribution function was measured over a polar angle range of 1-85°and a range of azimuthal angles of 0 -180°in 10°increments. The resultant directional-hemispherical reflectance is found by integration to be 1.00 Ϯ 0.01 at 442 nm, 0.953 Ϯ 0.01 at 632.8 nm, and 0.956 Ϯ 0.01 at 859.9 nm. The experimental methodology and the data analysis are presented together with a full discussion of the primary experimental errors.