Joseph Eugene Pierson

Full‐color photosensitive glass

New polychromatic (full‐color photosensitive) glasses are described in which the full color spectrum is developed by photochemical precipitation of subcolloidal silver too small to scatter light. The brilliant colors are shown to be due to selective light absorption by randomly oriented silver‐containing particles having controlled anisotropic shapes. The color photographic process and its chemistry are outlined. Controlled anisotropy is due to photo‐silver‐nucleated growth of elongated NaF⋅ (Na,Ag) X pyramidal crystallites, concentration of AgX at the apex, and subsequent photoprecipitation of this silver. Resultant colors are primarily a function of exposure flux (intensity × time) employing ultraviolet light (300 nm). The colors can be semiquantitatively described from electromagnetic theory assuming ellipsoidal metal particles suspended in a transparent dielectric medium. An absorption band moves across the visible spectrum as a function of particle eccentricity. Polychromatic glasses can be made havi...

Full-Colour (Polychromatic) Photosensitive Glass

AbstractA photochemical method is described for precipitating subcolloidal silver particles, having controlled variations in anisotropy, in a rigid glass matrix. Such particles, too small to scatter light, exhibit brilliant colours, covering the full visible spectrum.