METHOD OF TUNING RAPIDLY LASER AND RAPID TUNING LASER

摘要

Method and means are disclosed for rapidly tuning a laser over a large number of wavelengths. The means of the present invention includes first and second reflecting means which define the optical resonating cavity of a laser, and further includes a dispersive means adapted to sequentially select and direct one and only one of the wavelengths of light from the beam emitted by a laser's amplifying medium along a path back through the laser's amplifying medium as one of the reflecting means is continuously rotated. One embodiment of the present invention forms the rotating reflecting means as a faceted polygonal solid with at least one face thereof being a Littrow reflective grating. A pulsed laser is adapted to tune to a different wavelength of light each time some or all of the grating faces of the polygonal solid are rotated to intercept the longitudinal axis of the laser. A second embodiment forms the rotating reflecting means from a faceted polygonal solid but reflects laser light from the rotating reflected means to a single stationary Littrow grating. A third embodiment provides means and method of producing pairs of output pulses where the pair members are separated by a short time interval.