Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Study of tunable resonances in laser beam divergence and beam deflection   New, fundamental resonant properties of laser resonators are theoretically
predicted and experimentally demonstrated. These resonances occur either in the
time dependence of the beam width and that of beam radius of curvature of the
wavefront or in the time dependent pointing and position stability of the
output light beam of a laser resonator. The resonant frequency can be tuned
continuously from zero to the round-trip frequency in the first case; and from
zero to the half of the round-trip frequency in the second case, by for
example, moving one of the mirrors of the resonator. In both cases besides a
resonant frequency its complementary frequency to the round-trip frequency is
also resonant, and their shifted frequencies by multiples of the round-trip
frequency are also resonant. In our experimental demonstration we measured the
radiofrequency noise spectrum of the output laser beam, that was partially
blocked by a knife-edge. We observed increased noise at the theoretically
predicted frequencies. Similar resonances are predicted either in the time
dependent pulse-width and phase modulation or time jitter and the central
frequency of the ultrashort light pulses of the mode-locked lasers because of
the analogy between the space description of the light beams and the
time-description of the light pulses.

11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex