Manufacturers today are looking for
ways to pack in more data in laser
discs. But the most commonly used
lasers emit red light which has a
longer wavelength compared to blue
light. Attempts to make a blue semiconductor laser have so far not been
Now, a team of scientists from the Nichia Chemical Industries, Japan, have built a violet semiconductor laser using an alloy called gallium nitride. Successful trials will mean that the data packed in a compact disc will almost double (Science, Vo1271,No 5247).