This book deals with chromogenic materials and their uses primarily in large-area optical technology. The word "chromogenic" is new and is used here to denote materials which are able to alter their optical properties in response to a change in ambient conditions such as illumination intensity, temperature, applied electric field, etc. The changeable optical properties embrace transmittance, reflectance, absorptance and emittance.
C. M. Lampert, C. M. Lampert,
"Introduction to chromogenics", Proc. SPIE 10304, Large-Area Chromogenics: Materials and Devices for Transmittance Control, 1030402 (28 March 1990); doi: 10.1117/12.2283605; https://doi.org/10.1117/12.2283605