Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: All-Optical Realization of an Atom Laser   We demonstrate an atom laser using all-optical techniques. A Bose-Einstein
condensate of rubidium atoms is created by direct evaporative cooling in a
quasistatic dipole trap realized with a single, tightly focused CO$_{2}$-laser
beam. An applied magnetic field gradient allows formation of the condensate in
a field-insensitive $m_{F} = 0$ spin projection only, which suppresses
fluctuations of the chemical potential from stray magnetic fields. A collimated
and monoenergetic beam of atoms is extracted from the Bose-Einstein condensate
by continuously lowering the dipole trapping potential in a controlled way to
form a novel type of atom laser.

30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin