The upper energy level of laser emission typically needs to have a lifetime as short as possible in order to quickly emit the laser photons.

The refractive index of the cladding of an optical fiber is higher than that of the core, so that light can be confined and propagate along the core.

45.  It is extremely rare for people to recall events that occurred before the age of ______.

19.  The psychological experience created by the brain in response to changes in air pressure that are perceived in the auditory system is known as ______.

44.  Our recollection of the events that have occurred in our life and when those events took place is called ______ memory.

49.  Which of the following is true?

14.  ______ is the mental process of sorting, identifying, and arranging the raw data of experience into meaningful patterns.

36.  Presenting an aversive stimulus to eliminate undesired behavior is an example of ______.

25.  A biological cycle, or rhythm, that is approximately 24 hours long is a(n) ______ cycle.

28.  The initials REM stand for ______.