© oxford university press 2009 10.6 using lasers laser pointers a laser pointer uses a low power...
TRANSCRIPT
© Oxford University Press 2009
10.6 Using lasers
Laser pointersA laser pointer uses a low power laser.
Teachers and lecturers sometimes use them to point out things of special interest.
© Oxford University Press 2009
More laser pointersA laser level projects lines onto surfaces to help builders keep things level. You use the spirit level to get the device level and then a laser projects a straight line onto the surface you need to work with.
10.6 Using lasers
© Oxford University Press 2009
More laser pointersThe machines which scan barcodes at the supermarket use low-power lasers.
The light does not spread out so each set of strips, representing a number, can be read.
10.6 Using lasers
© Oxford University Press 2009
Playing compact discs (CDs)
A compact disc (CD) stores audio data such as music as a series of tiny pits which is read by a low-power laser.
The laser light does not spread out so can shine on an individual pit.
10.6 Using lasers
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Cutting CDs
A CD-ROM works in the same way as a compact disc except the data read by the laser is converted into a range of things such as instructions and graphics for a computer game.
A more powerful laser is used to burn the pits into the CD or CD-ROM.
10.6 Using lasers
© Oxford University Press 2009
High power lasers
High power lasers can cut out a shape or drill holes in metals.
The machine here is cutting a sheet of steel according to a pattern.
10.6 Using lasers
© Oxford University Press 2009
Cutting metal
A firefighter uses a high power laser to free a person trapped in a vehicle, following a road traffic accident.
It produces an intense beam of light that heats up the metal so that it can be cut away.
A second firefighter holds the victim still to prevent him aggravating any injuries he might have.
10.6 Using lasers