Eccentric infrared photorefraction is an attractive tool for measuring refractive errors of young children and uncooperative subjects, for it allows quick and non-invasive acquisition of data from both eyes simultaneously over a reasonably large dioptric range. Accuracy of refraction in this technique depends on calibration of luminance slope formed across the pupil into diopters (defocus calib...

We report what is to our knowledge the first observation of pixellike spatial solitons from partially spatially incoherent light. We created an array of as many as 32x32 soliton pixels by launching a spatially modulated incoherent light beam into a noninstantaneous self-focusing photorefraction medium. These solitons were stable and robust, forming a steady-state two-dimensional waveguide array...

Cavity nonlinear optics enables intriguing physical phenomena to occur at micro- or nano-scales with modest input powers. While this enhances capabilities in applications such as comb generation, frequency conversion, and quantum optics, undesired effects including photorefraction thermal bistability are exacerbated. In Letter, we propose demonstrate a highly effective method of achieving cavit...

OBJECTIVE The lag of accommodation which occurs in most human subjects during reading has been proposed to explain the association between reading and myopia. However, the measured lags are variable among different published studies and current knowledge on its magnitude rests largely on measurements with the Canon R-1 autorefractor. Therefore, we have measured it with another technique, eccent...

PURPOSE To investigate the nature of early ocular misalignments in human infants to determine whether they can provide insight into the etiology of esotropia and, in particular, to examine the correlates of misalignments. METHODS A remote haploscopic photorefraction system was used to measure accommodation and vergence in 146 infants between 0 and 12 months of age. Infants underwent photorefr...

Amorphous thin films from Ge-As-Te system were prepared by pulsed laser deposition to study their intrinsic photostability, morphology, chemical composition, structure and optical properties. Photostability of fabricated layers was studied by spectroscopic ellipsometry within as-deposited as well as relaxed (annealed) layers. For irradiation, laser sources operating at three wavelengths in band...

Photorefractive crystals exhibit large optical nonlinearities1 and have great potential in optical data processing.2 The extrinsic photorefractive effect in these electro-optic and photoconductive materials is rather well understood. The band-transport model' has been successfully employed to describe photorefraction in crystals such as the sillenite compounds, Bi12SiO2 0 and Bi12GeO 2 0 (BGO)....