Journal of the Optical Society of America
ISSN : 0030-3941
Published by: The Optical Society (10.1364)
Total articles ≅ 16,147
Latest articles in this journal
Journal of the Optical Society of America, Volume 73, pp 1725-1731; https://doi.org/10.1364/josa.73.001725
Cone oil droplets are highly retractile, optically dense spheres located in front of the cone outer segment. Because of their refractile strength, absorbance, and size, these spherical oil droplets have a pronounced influence on the light reaching the photopigment. We used electromagnetic scattering theory to interrelate these factors, and we calculated the light energy distribution around cone oil droplets modeled as isolated spheres. The necessary electromagnetic parameters were determined from anatomical and optical measurements in the turtle retina. Cone and oil-droplet dimensions were determined with a light microscope. The index-of-refraction values for the red, yellow, orange, and clear oil droplets were measured to be 1.69, 1.55, 1.51, and 1.48, respectively, by the technique of immersion matching. The application of the electromagnetic scattering theory suggests that oil droplets significantly increase cone sensitivity. Cone action spectra predicted by this analysis show that the largest increases o ccur around the absorption maximum of each cone's photopigment.
Journal of the Optical Society of America, Volume 73, pp 1674-1683; https://doi.org/10.1364/josa.73.001674
We studied the detection of coherent motion in stroboscopically moving random-dot patterns for foveal vision and at eccentricities of 6,12, 24, and 48 deg in the temporal visual field. Threshold signal-to-noise ratios (SNR's) were determined as a function of velocity for a range of stimulus sizes. It was found that the motion-detection performance is roughly invariant throughout the temporal visual field, provided that the stimuli are scaled according to the cortical magnification factor to obtain equivalent cortical sizes and velocities at all eccentricities. The maximum field velocity compatible with the percept of coherent motion increased about linearly with the width of the square stimuli. At this high-velocity threshold any pixel crossed the field in five to nine equal steps with a constant total crossing time of 50–90 msec, regardless of stimulus size or eccentricity. The lowest SNR values were reached at the optimal or tuning velocity V0. They approached the amazingly low values of 0.04–0.05 for large stimuli and at all eccentricities. Regardless of stimulus size, the parameter V0 increased about linearly with eccentricity from roughly 1 deg sec−1 at the fovea to some 8 deg sec−1 at 48 deg in the temporal visual field.
Journal of the Optical Society of America, Volume 73, pp 1622-1625; https://doi.org/10.1364/josa.73.001622
Information derived from the superior mirage is used to compute the average vertical temperature profile in the atmosphere between the observer and a known object. The image is described by a plot of ray-elevation angle at the eye against elevation at which that ray intersects the object. The computational algorithm, based on the tracing of rays that have at most one vertex, iteratively adjusts the temperature profile until the observed image characteristics are reproduced. An example based on an observation made on the Beaufort Sea illustrates the process.
Journal of the Optical Society of America, Volume 73, pp 1739-1743; https://doi.org/10.1364/josa.73.001739
We have measured as a function of incident angle, for a range of critical angles between 880° and 89° and of characteristic gain depths between 41 and 96 probe wavelengths, the single-pass reflectance of a He–Ne probe beam reflected from a transverse optically pumped solution of rhodamine B. In contrast to previously reported experiments, no anomalously high reflectances were observed. The theoretical formulas for the exponentially nonuniform- gain model reproduce well the observed reflectance curves including the locations, slopes, and heights of the amplification maximum in the vicinity of critical angle. Peak amplifications of 200–300% were predicted and observed for the given experimental conditions.
Journal of the Optical Society of America, Volume 73, pp 1825-1827; https://doi.org/10.1364/josa.73.001825
The directional behavior of power losses in aberrated multiaperture optical resonators with one or two phase-conjugate mirrors is investigated through integral equations and the reciprocity theorem. In a resonator with one phasecohjugate mirror, the losses of the mode traveling from the conventional mirror to the phase-conjugate mirror are shown to be larger than the losses of the counterpropagating mode. In a resonator with two phase-conjugate mirrors, the losses along each direction are found to be equal.
Journal of the Optical Society of America, Volume 73, pp 1828-1831; https://doi.org/10.1364/josa.73.001828
A discussion of the effect on the primary monochromatic aberrations of moving the stop or the object for a system of axially symmetric curved Fresnel surfaces is presented. Mathematical expressions, which are generalizations of similar results for non-Fresnel systems, for the changes in the aberrations are derived.
Journal of the Optical Society of America, Volume 73, pp 1846-1846; https://doi.org/10.1364/josa.73.001846
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Journal of the Optical Society of America, Volume 73; https://doi.org/10.1364/josa.73.001619
Journal of the Optical Society of America, Volume 73; https://doi.org/10.1364/josa.73.001850
Journal of the Optical Society of America, Volume 73; https://doi.org/10.1364/josa.73.001852