Two-mode gas lasers and their applications in spectroscopy and optical frequency standards (review)

Abstract

It is shown that, by usual definition about the Hopf term, the Skyrmions in the (2+l)-D 0(3) non-linear a model with this term have only integer spin. A modified definition about the term is suggested to make the Skyrmions have probability to possess fractional spin.

<title>Double-mode CO2 laser with complex cavity for ultrasensitive sub-Doppler spectroscopy</title>

“…i: order to investigate the behavior of the field intenities in the first I , I, and the second 12a, 12y sections and frequencies of mode beats v z' zi (v2,, are the frequencies of the generated modes) it is neceseary to consider a set of six equations: R(R2A2 + RiAiG,,)sin V,, = (R1R2A1A2G,, + 1)sinU,, (1) R(R2A2 RiAiG,,) cos Vs,,, = (R1R2A1A2G,,,, -1) cos U,,,,…”

He-Ne (λ = 1.15 μ) laser with two orthogonally polarized modes

“…These lasers possess qualitatively new features promising for different applications. Such features (the controlled coupling between the modes, the tunable spectrum, and the detection possibility of each mode severally) allow the light sources with special characteristics or the sensors for precise measuring to be obtained [5][6][7][8][9][10]. These lasers differ in design from the ordinary type, in that one or several transparent optical elements possess natural or artificial birefringence installed into the laser cavity (Fig.…”