Numéro
J. Phys. Colloques
Volume 42, Numéro C8, Décembre 1981
Troisième Symposium sur les Etalons de Fréquence et la Métrologie / Third Symposium on Frequency Standards and Metrology
Page(s) C8-495 - C8-503
DOI https://doi.org/10.1051/jphyscol:1981855
Troisième Symposium sur les Etalons de Fréquence et la Métrologie / Third Symposium on Frequency Standards and Metrology

J. Phys. Colloques 42 (1981) C8-495-C8-503

DOI: 10.1051/jphyscol:1981855

OPTICAL FREQUENCY SYNTHESIS AT NPL

D.J.E. Knight

Division of Quantum Metrology, National Physical Laboratory, Teddington, Middlesex, TW11 OLW, U.K.


Abstract
Current activities relevant to laser frequency measurement are discussed. The main emphasis is an extending frequency measurement from the 3.39 µm region to the visible, for which a particular frequency synthesis scheme is presented. Experimental results are given on phase locking gas lasers together and on checking the equivalence of frequency doubling in a phase-matched crystal and in a point contact device. Technical improvements of Josephson junction devices are mentioned.