In the following device the laser is the red light and there is diffusion lens to dread the light out over a larger distance for field illumination. Spot size is several centimeters.
The hand held laser to be used for the purpose of illuminating tumors during surgery. The laser needs to output 5-10 mW/cm2 at 760 nm after it is passed through a diffusion de focus lens to give a spot size of around 4 cm at 18-20 inches. The laser needs to have a usable on time of 3-4 minutes at a time.