Patent ID: 8636726

Claim:
An apparatus comprising: a dual-mode laser device configured to operate in a first mode and a second mode, wherein, in the first mode, the dual-mode laser device generates CW or quasi-CW laser light that is configured to coagulate fluids in human tissue, wherein, in the second mode, the dual-mode laser device generates pulsed laser light such that each pulse of the pulsed laser light has a pulse duration tunable between about 1 nanoseconds (nsec) and about 300 nsec, each pulse has a tissue-penetration depth tunable between about 0.1 millimeters (mm) and about 1 mm, and the pulse duration of each pulse is less than or equal to δ/V s , where δ is the tissue-penetration depth and V s is the speed of sound in the human tissue, and wherein the pulsed laser light is configured to cause-precise laser ablation of human tissues in an irradiated tissue zone within a medical procedure by localized stress-confined tissue damage that creates micropores in the tissue with minimal collateral damage outside the irradiated tissue zone, the dual-mode laser device including: a first fiber gain-medium section, wherein the first fiber gain-medium section is configured to be optically pumped to generate a ring signal laser beam; a ring optical signal path that extends through the first fiber gain-medium section, wherein the ring signal laser beam is propagated across the ring optical signal path; and a Q-switch located between free-space parts in the ring optical signal path but outside of the first fiber gain-medium section, wherein the Q-switch is configured to generate the pulsed laser light of the second mode.