Abstract: The invention relates to a microlaser cavity switched with the aid of an electrooptical material (54). Electrodes (84, 86) are produced on support elements (80, 82) and the latter are then applied on either side of the electrooptical element. Solid electrodes can also be applied on either side of the electrooptical material.

Abstract: Compact electron gun having a microdot electron source and a semiconductor laser using said gun for electronic pumping. A compact electron gun is provided having a microdot electron emitting source (2), an anode (8) spaced from the microdots, means (16) for applying a high voltage to the and, array (10) of electrodes distributed around the bean emitted by the source for the strip focussing thereof onto the anode. The array also serves as an electrostatic screen for the source with respect to the high voltage of the array. The array is positioned between the source and the anode and has at least two pairs of electrodes (18, 18b, 20a, 20b) of different dimensions which are raised to respectively positive and negative voltages. The positive and the negative voltages produce a weak electrostatic field between the source and the electrode array and a strong electrostatic field between the electrode array and the anode.

Abstract: A semiconductor heterostructure laser cavity is disclosed which has semiconductor layers epitaxied to define four zones on a substrate. The laser cavity includes a first zone with a composition that varies continuously from a first face to a second face with a gap decreasing from the first face to the second face, the first zone ensuring an optical confinement and light guidance. A second zone constitutes an active emission zone in contact with the second face of the first zone and having at least one quantum well with a gap smaller than that of the first zone. A third zone has a gap larger than that of the at least one quantum well. The third zone ensuring an optical confinement and a light guidance, and having a composition which varies continuously from a first face to a second face with a gap which increases from the first face to the second face, the first face of the third zone being in contact with the active emission zone.