In memory of Yurii Vasil'evich Kopaev Alferov, Zhores I; Andreev, Aleksandr F; Aseev, Aleksandr L ...
Physics Uspekhi,
05/2013, Letnik:
56, Številka:
5
Journal Article
In memory of Aleksei Maksimovich Fridman Andreev, Aleksandr F; Bagaev, Sergei N; Boyarchuk, Aleksandr A ...
Physics Uspekhi,
05/2011, Letnik:
54, Številka:
5
Journal Article
We report high-precision frequency measurements of the separate hyperfine structure (HFS) components of the emission B - X system transitions of {sup 127}I{sub 2} molecules in the 982 - 985 nm range. ...To resolve the HFS of the emission lines, advantage was taken of the method of three-level laser spectroscopy. The function of exciting radiation was fulfilled by the second harmonic of a cw Nd : YAG laser, and the probe radiation in the 968 - 998 nm range was generated by an external-cavity diode laser. The output Nd : YAG laser frequency was locked to an HFS component of the absorption transition and the probing laser radiation to the emission transition component. When both frequencies were locked to HFS components with a common upper level, the output diode laser frequency was precisely equal to the emission transition frequency. The output frequency of the thus stabilised diode laser was measured with the help of a femtosecond optical frequency synthesiser based on a Ti : sapphire laser. We present the results of the absolute frequency measurements of 20 HFS components belonging to six vibrational - rotational transitions of the B - X system of iodine R56(32 - 48)a1, P58(32 - 48)a1, P85(33 - 48)a1, R87(33 - 48a1, R88(33 - 48)a10 and all 15 components of the R86(33 - 48) line. The relative measurement uncertainty is equal to 7 Multiplication-Sign 10{sup -10} and is determined by the frequency instability of the diode laser radiation.
25%Eu : KGd(WO{sub 4}){sub 2} crystal is grown by a modified Czochralski method and its spectral and lasing properties are studied. Generation of stimulated emission in this crystal on the {sup ...5}D{sub 0}{yields}{sup 7}F{sub 4} transition of the Eu{sup 3+} ion is obtained, as far as we know, for the first time. The laser operates at room temperature at a wavelength of {approx}703 nm under pumping into the {sup 7}F{sub 0}{yields}{sup 5}D{sub 1} absorption band of the europium ion by the second harmonic of a Q-switched Nd : KGW laser ({lambda}{sub pump}= 533.6 nm). With a 9.4-mm-long active element, the output energy in the free-running regime reached 244 {mu}J, while the optical efficiency was 1.5%. (lasers and active media)
