Laser Sources differ from traditional illumination sources because they produce coherent light. The illumination spectrum is often narrow band with line widths as narrow as tens of megahertz and divergence as low as fractions of milliradians. Lasers are either utilized in free space, steered with traditional optics, or the source is coupled into a fiber. In a fiber coupled orientation, the emitting fiber tip is mounted at the location of beam delivery, reducing the need for steering optics. When a laser is fiber coupled, a cone of light is produced instead of a collimated beam.