Generation of polarisation-nonuniform modes in a high-power CO{sub 2} laser

Journal Article · Tue Jun 30 00:00:00 EDT 2009 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QE2009V039N06ABEH013962· OSTI ID:21467115

Niz'ev, Vladimir G; Yakunin, V P ^[1]; Turkin, N G ^[2]

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1. Institute on Laser and Information Technologies, Russian Academy of Sciences, Shatura, Moscow Region (Russian Federation)
2. State Research Center of Russian Federation 'Troitsk Institute for Innovation and Fusion Research', Troitsk, Moscow Region (Russian Federation)

A method describing radially and azimuthally polarised laser modes is presented, which is devoid of intrinsic contradictions and unjustified restrictions. The solutions of the wave equation found in the paper satisfy Maxwell's equation bigtriangledownE = 0. This allowed the calculation of all the components of the fields of such modes, including the longitudinal one. Expressions for tight focusing of radially and azimuthally polarised modes are obtained in the Debye approximation. The methods of intracavity generation of such modes in a high-power industrial CO{sub 2} laser are experimentally realised and methods of mutual transformation of these modes outside the cavity are developed. The intracavity generation of azimuthally polarised modes was achieved by using as a rear highly reflecting mirror either V-shaped axicons or metal diffraction mirrors with the relief period comparable to the wavelength. Radially polarised radiation was generated by using diffraction mirrors with the relief period of the order of two wavelengths. The polarisation-nonuniform TEM{sub 01*} and TEM{sub 11*} modes of power up to 1.8 kW are generated for the first time. In this case, the degree of polarisation was close to 100% within the entire radiation power range both in the near- and far-field zones. By using two half-wave phase shifters, the azimuthally polarised radiation is transformed to radially polarised radiation and vice versa, the energy efficiency of this transformation being 92%. These results open up the possibility for industrial applications of such radiation. (control of laser radiation parameters)

• OSTI ID: 21467115
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Vol. 39, Issue 6; Other Information: DOI: 10.1070/QE2009v039n06ABEH013962; ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON DIOXIDE LASERS
DIFFRACTION
ENERGY EFFICIENCY
FOCUSING
LASER CAVITIES
LASER RADIATION
MATHEMATICAL SOLUTIONS
MAXWELL EQUATIONS
MIRRORS
OSCILLATION MODES
PHASE SHIFT
POLARIZATION
POWER RANGE
WAVE EQUATIONS
WAVELENGTHS
COHERENT SCATTERING
DIFFERENTIAL EQUATIONS
EFFICIENCY
ELECTROMAGNETIC RADIATION
EQUATIONS
GAS LASERS
LASERS
PARTIAL DIFFERENTIAL EQUATIONS
RADIATIONS
SCATTERING