Laser system with a circular beam profile

摘要

A laser system 10 has a diode laser 12 which produces an output beam of radiation, a first feedback means and a second feedback means. The first feedback and second feedback means interact with the output beam to produce a resultant beam of radiation having a substantially circular cross-sectional area. The laser system 10 may be comprised of a diode laser 12, a convex lens 14 with an antireflective coating, and a diffraction grating 16. The convex lens 14 and diffraction grating 16 may act as the first feedback means and second feedback means. The convex lens 14 may be non frequency selective so as to produce a substantially non-dispersive feedback, with the diffraction grating 16 being frequency selective so as to produce a dispersive feedback. The diffraction grating 16 can be arranged so the first order maximum of the grating is fed back to the diode laser 12 and the zeroth order of the diffraction grating is used as a resultant output beam 24. The diffraction grating 16 can be mounted on an adjustable stage 42 so that the angle of the diffraction grating relative to the output beam 24 can be altered so as to provided a tuneable laser system. A method of modifying an output of the diode laser to provide a substantially circular output beam is also provided.