METHOD OF INCREASING THE MAXIMUM LASING ENERGY OF A RAMAN LASER EMITTING AT A WAVELENGTH SAFE FOR VISION
The author investigated Raman self-conversion laser, designed for rangefinder, operating at eye safe diapason at λ = 1.538 µm. The laser is consist of on the active element from a potassium gadolinium tungsten crystal KGd(WO4)2; Nd3+ and a crystal passive laser Q-switcher made from YAG : V3+ crystal, pumped by a pulsed Xe-lamp placed in a silvered tubular reflector. The laser generation was beginning at the wavelength of λ = 1.351 µm and was converted inside the active element at the first Roman Stokes component λ = 1.538 µm. The cross-section of the stimulated radiation at λ = 1.351 µm is four times lower than the cross-section of the stimulated radiation at the wavelength λ = 1.067 µm, so the competition of the amplification processes at these two wave-lengths has a determining value on the energy of the laser generation. In the passive Q-switched mode, the max-imum values obtained for four different sizes of active elements of KGW : Nd3+. The value of the obtained maxi-mum generation energy was proportional to the volume of the active element (as far as the author knows, it was noticed for the first time) and was determined by the gain coefficient, at which a significant removal of inversion at a competing wavelength λ = 1.067 µm began. The method reducing competing processes of the inversion re-moval at λ = 1.067 µm was proposed.
Authors: V. N. Ivanov
Direction: Instrument Engineering and Information-Measurement Technologies
Keywords: Raman, self-conversion, laser, eye safe
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