Blue laser light has very widespread applications. For example, the blue laser light may be applicable to high-density optical storage or even medical science. Conventionally, the high-density optical data stores are operated with red diodes at the wavelength of about 650 nm. Through the use of shorter-wavelength blue laser radiation (about 405 nm), the next generation of optical data stores, e.g. DVDs, are currently introduced onto the market to be written or read by means of a blue laser light in a high-density manner. Generally, the DVDs applied in the blue laser technology are classified into two types, for example blu-ray discs and advanced optical discs (AODs).
According to the blue laser technology, the light-absorbent substances used in the optical discs are very important for adsorbing blue laser light. Generally, the light-absorbent substances include organic dyes and inorganic phase-changeable materials. The organic dyes displaying an intense absorption in the wavelength range of 390 to 490 nm (e.g. 405 nm) can be used for adsorbing the blue laser light. Examples of the organic dyes include cyanines, porphyrins, polyenes, azo compounds, dicyanovinylphenyl compounds, etc.
To achieve excellent optical properties, the dyes should have a high molar extinction coefficient at the blue light absorption wavelength. Moreover, photosensitivity, solubility, light fastness and writing power are also important for selecting suitable dyes.
Therefore, there is a continuous need of providing better blue laser light-absorbent substances, which can satisfy the abovementioned requirement profile particularly well.