The main advantages of organic photochromic compounds used in optical information storage media are as follows:
(1) High storage density and large storage capacity. Organic materials use molecular changes to record information, which can realize molecular memory in theory. (2) High sensitivity and fast response, which can reach nanosecond level or even shorter. (3) Low production cost and easy processing. (4) The signal-to-noise ratio is high. (5) Good diamagnetism. Because most organic materials are not affected by magnetic fields. (6) optics .374
The performance can be adjusted by changing the molecular structure so as to be suitable for various laser wavelengths. (7) Low toxicity.
At present, the research focus of organic photochromic optical storage materials is to find high fatigue resistance and stable writing and reading States. A photochromic material with real practical application prospect should meet the following conditions:
(1) It has good anti-fatigue performance, especially eight/you seem to be in danger of spot operation (4) It can keep information in secret with commercial semiconductors for a long time. (3) The sensitivity of the sky is the same, and the fat-and-drink-to-drink ratio is not matched with the laser with the wavelength matching of the semi-pilot laser. With the semiconductor excitation, the five-north (low-tech) anvil is read out. (6) Solubility has become an important indicator of photochromic materials. Several lines (lIA) the recording layer is made by spinning laurel cloth method. Good, in polymer medium or inorganic solid, it can keep the UV-B emission, and VB will be used as (7) chromophore, and its absorption is very weak in the spectral range of excitation light of colorless body, otherwise it will be used as (7) chromophore after it is generated.
Optical filter greatly reduces the quantum efficiency of photochromism reaction.
17.2 transition metal oxide semiconductor photochromic materials
17.2.1 Introduction
Photochromism refers to the reversible change of a substance between two physical or chemical states, in which at least one direction change is caused by light radiation.
Its basic characteristics are: 1) Ti and T2 can exist stably under certain conditions; 2) The color parallax between T and T2 is significantly different; 3) The change between Ti and Tz is reversible. Because of these excellent characteristics, materials can be used in display materials, sensors and decorative materials. To be practical, the R of TTaT1 should be stable enough. B)T,T2 have a long enough cycle life; C) the absorption band is in the visible region.