Etienne-Louis Malus

Etienne-Louis Malus (July 23, 1775 – February 24, 1812) was a French officer, engineer, physicist, and mathematician.

Related Topics:
July 23 - 1775 - February 24 - 1812 - French - Officer - Engineer - Physicist - Mathematician

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Malus was born in Paris, France. He participated in Napoleon's expedition into Egypt, 1798 to 1801. Malus became a member of the Académie des Sciences in 1810.

Related Topics:
Paris - France - Napoleon's - Expedition into Egypt - 1798 - 1801 - Académie des Sciences - 1810

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His mathematical work was almost entirely concerned with the study of light. He studied geometric systems called ray systems, closely connected to Julius Plücker's line geometry. He conducted experiments to verify Christiaan Huygens' theories of light and rewrote the theory in analytical form. His discovery of the polarisation of light by reflection was published in 1809 and his theory of double refraction of light in crystals, in 1810.

Related Topics:
Light - Geometric - Julius Plücker - Line geometry - Christiaan Huygens - Polarisation - Reflection - 1809 - Double refraction - Crystal

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He is probably best remembered for Malus' law, giving the resultant intensity, I, when a polarizer is placed in an incident beam of intensity I0:

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:I = I0 cos2 θ,

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where θ is the angle between the polarisation direction of the incident beam and the axis of the polariser.

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