Abstract: Disclosed is a laser system comprising: A laser assembly (101) comprising a plurality of emitters; first and second light feedback devices (208, 232) forming respective external cavities with the laser assembly; a dispersive device (205) for redirecting respective portions of the light from the laser assembly to the first and second feedback devices (208, 232), wherein the first feedback device (232) is adapted to reflect a feedback portion of the redirected beam back onto the dispersive device (205) and to generate the output beam (233) from an output part of the first redirected beam, —an imaging device (213) for generating an optical Fourier transform of the plurality of emitters at a Fourier plane (235). The dispersive device (205) is positioned displaced from said Fourier plane (235) by a predetermined displacement (d) in a direction along said principle axis (230).

Abstract: A diode laser system having a diode amplifier member with a large transverse gain area. The diode amplifier member includes an amplifying medium for amplifying a number of spatial modes of a spatial light distribution. The laser system further includes a number of passive reflective members forming a laser cavity which includes at least a part of the diode amplifier member, each of the passive reflective members being adapted, during operation, to reflect light at least partially into the amplifying medium. The passive reflective members are adapted, during operation, to induce, via the light reflected by them, a self-induced dynamic gain and refractive index grating in the diode amplifier member, the dynamic gain and refractive index grating selecting one of said spatial modes and suppressing at least a part of the remaining spatial modes of the spatial light distribution.

Abstract: A diode laser system providing a high-power laser beam with good spatial coherence, which can be focused to a small spot size over long distances and which has a good pointing stability. The laser system comprises a laser diode (301) adapted to emit a first light beam, where the first light beam comprises a plurality of spatial modes, selection means (304) adapted to select a predetermined part of the first light beam, and a reflector (306), where the laser diode and the reflector define a cavity and where the reflector is adapted to reflect the selected part of the first light beam back into the laser diode as a second light beam. The laser system is characterised in that the selection means is adapted to select a part of the first light beam corresponding to a spatial mode with a higher mode number than a spatial mode with maximum gain.

Abstract: The present invention relates to a system and a method for emitting plane laser light to biological tissue, wherein in high power lasers are modulated in order to provide an output beam consisting of high temporal and/or spatial coherence and at the same time is capable of delivering an output beam having a high power when being delivered through fibres having a core diameter of less than 400 &mgr;m. The method and system may in particular be used for photodynamic treatment (PDT) Optical fibers and/or thermal treatment. In a preferred embodiment the system and method also includes a monitoring system for the effect actually delivered to the biological tissue. Furthermore, the invention relates to a method of treatment using the system, as well as a method for diagnosing using the system.