A double-sided optical disc, such as a DVD-18 disc, is formed with data tracks on each layer. The tracks on one side are oriented along one spiral while the tracks on the other side are oriented along a second spiral, the two spirals being oriented in opposite directions as viewed from the respective sides. A player with two laser read heads is provided for reading the disc. Each laser read head is disposed adjacent to a respective disc side. The data is read from the two sides, either in sequence from one side and then the other, simultaneously, or in some alternating fashion.

 
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> Method of fabricating semiconductor laser

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