Standing-wave cavities

Let us consider thermal radiation in a certain cavity at a temperature T. By the term thermal radiation we mean that the radiation field is in thermal equilibrium with its surroundings, the power absorbed by the cavity walls, Fa (v), being equal to the emitted power, Pe v), for all the frequencies v. Under this condition, the superposition of the different electromagnetic waves in the cavity results in standing waves, as required by the stationary radiation field configuration. These standing waves are called cavity modes. 

Different axial modes (optical standing waves) can be set up in a cavity of length L provided that the frequency v fulfills the condition... 

The electromagnetic field in the cavity is a standing wave which can be described as a superposition of two travelling waves propaga-... 

One method which employs the saturable absorption of intracavity gaseous absorbers has turned out to be strikingly successful333) As explained in the last section, the absorption profile of a gas interacting with a monochromatic standing wave inside the laser cavity exhibits a sharp minimum at the center of the unsaturated ab-... 

A standing wave (SW) microwave linear accelerator consists of a linear array of resonant cavities that are energized by a common source of microwave power. These cavities are nearly isolated by webs with small-diameter apertures, and the high-energy electron beam passes through these apertures. However, they are coupled through intermediate cavities, which stabilize the microwave phase relationship between the accelerating cavities. 

Figure 7.14 Principles of mode-locking, (a) Standing waves in a cavity of length L defined by two mirrors mp, m2, (b) Selection of frequencies within the emission spectrum of the lasing material v is the frequency...

Cavities. The sample is contained in a resonant cavity, which is a structure capable of supporting a standing-wave pattern. The cavity is analogous to a tuned circuit (e.g., a parallel RLC combination) used at lower frequencies and must be matched to the klystron frequency range. A measure of the quality of the cavity is its Q or Q factor, which is defined as... 

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