You may be wondering how the laser comes to reach organs inside the body. The answer to this is another fantastic laser related technology known as fiber optics. Laser light passes through extremely thin hollow tubes without losing intensity or changing color. Optical fibers can be inserted into natural or surgically created holes in the body. Light can be received through one fiber and transmitted through another. This way a doctor can both see the problem and effect it.

For instance, a small hole in the stomach can be made with a laser incision. An optical fiber is inserted to reach the gallbladder. A long pulse laser is used to cut out the diseased gallbladder from the surrounding liver tissue, sealing the surrounding blood vessels to avoid excess bleeding. Then, the doctor can attempt to pull the gallbladder out of the hole. Sometimes the gallbladder is so ladden with hard mineral deposits (gallstones) that it doesn't fit through the hole. To remedy this, the doctor can hit the stones with a pulsed laser that causes a shock wave in the gallstones, breaking them apart. This procedure illustrates how different elements of laser technology are used in medicine.