Blue laser advances

1997/01/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Teknologia

The blue laser is much thinner than red, so on the CD-Rom you can read ten times more information. However, there are great difficulties in getting the blue laser, but a Japanese team has advanced a lot.

Shuji Nakamura, from Nichia Chemical Industries, has prepared a first blue-purple laser that has put the issue to the top. Among other things, the compact disc reads ten times more information than the red laser, since its wavelength is shorter. The smaller the wavelength, the narrower the laser beam, allowing you to read information located in a smaller place on the CD or CD-Rom. Therefore, more information can be saved in the same place.

However, the realization of these small wavelength lasers is difficult, but his has been prepared by Shuji Nakamura, who also prepares blue-purple, that is, of lesser wavelength than blue. To do this, the Japanese researcher has ruled out classical semiconductors, including those of zinkseleniuro. He has chosen gallium nitride (GaN), robust due to significant variations in temperature and tension.

The gallium nitride currently used presents numerous defects: one billion square centimeters. So much lack in any other laser prevents the emission of rays, but gallium nitride, despite its abundance of impurities, does not damage much the beam of light emitting.

Toshiba has already announced the improvement of gallium nitride. Therefore, the blue laser will be published soon. The combination with red and yellow laser will allow you to obtain all the colors. Among others, the possibility of building very fine TV screens and HD copiers is open.