Showing papers in "Optics News in 1987"

Fiber-optic measurements

Abstract: Fiber-optic technology has its own distinct set of measurements, based largely on a mixture of optical and electronic techniques. This chapter covers the important optical aspects of fiber-optic measurements, assuming you know something about electronics. It covers measurement units, the quantities measured, and the types of measurements performed, pointing out differences between optical and electronic measurements. The emphasis here is on basic optical concepts that you need to know when working with fiber optics. The next chapter covers fiber-optic test equipment, along with its use in troubleshooting fiber-optic systems.

Spatial factors limiting stereopsis and fusion

Abstract: The a p p r e c i a t i o n o f re la t i ve depth between two or more ob­ jects can be derived f rom the s l ight ly di f ferent perspect ive w i t h which our two eyes view the wor ld . This perspective leads to the forma­ tion of both absolute and relative hor­ izontal retinal image disparities. A b ­ solute disparities are defined as the difference between the v isual angle subtended by a target at the entrance pupils of the two eyes and the eye's angle of convergence. In contrast, rel­ ative disparity is independent of the angle of convergence or even the di ­ rection of gaze. It equals the differ­ ence in v isual angles subtended by two targets at the entrance pupils of the two eyes.