<Table> Light - emitting diode <Tr> <Td_colspan="2"> Blue, green, and red LEDs in 5 mm diffused case </Td> </Tr> <Tr> <Th> Working principle </Th> <Td> Electroluminescence </Td> </Tr> <Tr> <Th> Invented </Th> <Td> H.J. Round (1907) Oleg Losev (1927) James R. Biard (1961) Nick Holonyak (1962) </Td> </Tr> <Tr> <Th> First production </Th> <Td> October 1962 </Td> </Tr> <Tr> <Th> Pin configuration </Th> <Td> Anode and cathode </Td> </Tr> <Tr> <Th_colspan="2"> Electronic symbol </Th> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> </Table> <Tr> <Td_colspan="2"> Blue, green, and red LEDs in 5 mm diffused case </Td> </Tr>

State the basic operating principle of an led