Photonics Dictionary: Q

Q-switched operation, or q-switching, is a technique used in lasers to produce short and intense pulses of light. The term "Q" in q-switching stands for "quality factor," which is a measure of the...

A laser output that occurs when the cavity resonator Q is first kept very low, using rotating mirrors or saturable absorbers, so that the population inversion achieved is greater than usual. A high...

A device with a limited number of possible output values (sometimes able to be selected) that can translate an incoming signal into these values or codes for outputting. See pulse code modulation. In...

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics. It is a versatile and powerful device used for emitting coherent light in...

Quantum efficiency (QE) is a measure of the effectiveness with which a device or system, typically in the context of photonics or electronics, converts incoming photons (light) into a useful output...

A laser that generates a succession of pulses at a high enough repetition rate to appear continuous. The pump source is switched on for short intervals, nominally equal to the lifetime of the...