Originally posted by Andrikos
ANYTHING is more efficient than laser diodes. LASER needs a LOT of power and cooling.
Why does everyone here think LED's are more efficient than laser diodes? According to the graduate electrical engineering class I just took, laser diodes are always more efficient than the equivalent LED.
A laser diode is just an LED with special properties: frequency is tuned to the size of the resonant cavity in the silicon, cavity has mirror surfaces, etc.
The reason an LED is more inefficient than its equivalent laser diode: most of the light never leaves the silicon, it is reabsorped and turns into heat, where as in a laser diode, almost all of the light travels in a single path out of the mirror faces.
Also, the way coherent light emission is stimulated by other photons is more efficient than the way non-coherent light just randomly "occurs" in an LED.
I'm not saying all lasers are efficient, just that an LED tuned to be a laser is more efficient than the LED.