PURPOSE: To facilitate changing the oscillation frequency of a semiconductor laser chip quickly by a method wherein a magnetic field applied to the semiconductor laser chip is controlled by currents applied to superconductors and the superconductors do not have an LR time constant which an electromagnet has.
CONSTITUTION: As magnetic lines of force do not enter a space between facing superconductors 3 and 4 by the Meissner effect of the superconductors 3 and 4, the magnetic field is not applied to a semiconductor laser chip 7. If currents of 10000A/cm2 are applied to the respective superconductors 3 and 4, superconductive states of the superconductors 3 and 4 are relieved and converted into normal conductive states and the magnetic lines of force are applied to the semiconductor laser chip 7 through the superconductors 3 and 4. With this constitution, as the magnetic field applied to the semiconductor laser chip 7 is controlled by the currents applied to the superconductors 3 and 4 and the superconductors 3 and 4 do not have an LR time constant, the oscillation frequency of the semiconductor laser chip can be changed quickly.
KUWANO YUKINORI
SUZUKI IKUHISA
YOSHISATO MASANOBU
YOKOO TOSHIAKI
KONISHI FUMITO
IKEMACHI TAKAAKI
TAKAHASHI KAZUHIKO
IENAGA TERUHIKO
