A dye thin film containing a dye compound represented by the general formula (I), an optical switch, an optical distributor, an optical modulator and an optical switch array having the dye thin film, as well as a method for producing a dye thin film are provided. The method includes the step of coating the solution of the dye compound on a substrate: ##STR1## where R.sub.1 and R.sub.2 may be identical or different from each other and each represents, respectively, a linear alkyl group or a branched alkyl group, the dye thin film having high thermal stability, having intense absorption at approximately 1.3 .mu.m and having ultrafast response characteristic.
A dye thin film containing a dye compound represented by the general formula (I), an optical switch, an optical distributor, an optical modulator and an optical switch array having the dye thin film, as well as a method for producing a dye thin film are provided. The method includes the step of coating the solution of the dye compound on a substrate: ##STR1## where R.sub.1 and R.sub.2 may be identical or different from each other and each represents, respectively, a linear alkyl group or a branched alkyl group, the dye thin film having high thermal stability, having intense absorption at approximately 1.3 .mu.m and having ultrafast response characteristic.
A dibenzofuranonylium methylate compound represented by the following formula (I), having maximum absorption wavelength of over 1 .mu.m, high thermal stability and good solubility in organic solvents, and a production method thereof are provided: ##STR1## where R.sub.1 and R.sub.2 may be identical or different from each other and each represents a linear alkyl group or a branched alkyl group, respectively.
A dibenzofuranonylium methylate compound represented by the following formula (I), having maximum absorption wavelength of over 1 .mu.m, high thermal stability and good solubility in organic solvents, and a production method thereof are provided: ##STR1## where R.sub.1 and R.sub.2 may be identical or different from each other and each represents a linear alkyl group or a branched alkyl group, respectively.
Provided is an optical switching system which is capable of being operated at a very high speed in a communication wavelength region and of meeting the various requests at a high grade by the provision of an optical switching system having such a construction that a signal light composed of a light pulse train, and a pulse-like control light synchronous therewith are applied to a light control portion composed of a thin film made of carbon nanotubes to selectively transmit the light pulse train in the signal light through the thin film to form an output signal light and then receiving the output signal light thus formed is received.