DesertFox
03-29-2006, 01:08 AM
Barry Fox
NewScientist.com
28 Mar 06
The spark plugs inside an internal combustion engine erode and need to be replaced regularly because high voltages are required to ignite the engine fuel.
Colorado State University in the US hopes to create longer-lasting plugs by replacing electrical ignition with pulsed laser light, fed into the cylinders by glass fibres.
But so much energy is needed to ionise gas and create a spark that conventional optical fibres disintegrate. So the university is patenting a new fibre that promises to be strong enough to feed laser power to spark plugs.
The fibre is hollow, 700 micrometres in diameter and filled with helium. The internal surface of the tube is coated with a 0.2 micrometre layer of reflective silver.
The silver coating should stop light from escaping and the inert helium should prevent the creation of any sparks inside the fibre.
Infrared light from a neodymium-YAG laser is fired into the tube, which carries it round bends and into the engine cylinders where a lens focuses all the energy onto a fine spot. This triggers the electrical breakdown of gas inside the cylinder and generates a plasma spark that ignites the fuel.
Source (http://www.newscientist.com/article/dn8907-invention-laser-spark-plugs.html)
NewScientist.com
28 Mar 06
The spark plugs inside an internal combustion engine erode and need to be replaced regularly because high voltages are required to ignite the engine fuel.
Colorado State University in the US hopes to create longer-lasting plugs by replacing electrical ignition with pulsed laser light, fed into the cylinders by glass fibres.
But so much energy is needed to ionise gas and create a spark that conventional optical fibres disintegrate. So the university is patenting a new fibre that promises to be strong enough to feed laser power to spark plugs.
The fibre is hollow, 700 micrometres in diameter and filled with helium. The internal surface of the tube is coated with a 0.2 micrometre layer of reflective silver.
The silver coating should stop light from escaping and the inert helium should prevent the creation of any sparks inside the fibre.
Infrared light from a neodymium-YAG laser is fired into the tube, which carries it round bends and into the engine cylinders where a lens focuses all the energy onto a fine spot. This triggers the electrical breakdown of gas inside the cylinder and generates a plasma spark that ignites the fuel.
Source (http://www.newscientist.com/article/dn8907-invention-laser-spark-plugs.html)