Calculation of the velocity and threshold of a thermal absorption wave of laser radiation in an optical fibre

Journal Article · Tue Aug 31 00:00:00 EDT 2004 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QE2004V034N08ABEH002844· OSTI ID:21470581

Tkachev, Aleksei N; Yakovlenko, Sergei I ^[1]

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1. A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

Based on the nonstationary one-dimensional heat conduction equation, taking the efficient heat removal into account, a thermal absorption wave of laser radiation in the core of an optical fibre is studied. The dependence of the wave velocity on the laser radiation intensity is calculated and threshold intensities at which the thermal wave appears are estimated. It is shown that the wave velocity at high intensities is well described by the formula known from the combustion theory and is proportional to the square root of the radiation intensity. Simple expressions are derived which describe the dependence of the threshold intensity on the effective cooling radius and the dependence of the wave velocity on the radiation intensity (including the near-threshold region). The calculated threshold intensities of laser radiation are approximately twice those needed to obtain the equality between the power coupled to the fibre and the effective heat removal power. The calculated dependences of the wave velocity on the radiation intensity and threshold intensities are in agreement with the experimental data available. (optical fibres)

• OSTI ID: 21470581
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Journal Name: Quantum Electronics (Woodbury, N.Y.) Journal Issue: 8 Vol. 34; ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
CHEMICAL REACTIONS
COMBUSTION
COOLING
DATA
ELECTROMAGNETIC RADIATION
ENERGY TRANSFER
EQUATIONS
EXPERIMENTAL DATA
FIBERS
HEAT TRANSFER
INFORMATION
LASER RADIATION
NUMERICAL DATA
ONE-DIMENSIONAL CALCULATIONS
OPTICAL FIBERS
OXIDATION
RADIATIONS
SORPTION
THERMAL CONDUCTION
THERMOCHEMICAL PROCESSES