Patent ID: 8353899

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, 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 rare-earth doped large-mode-area (LMA) 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; one or more passive polarization-maintaining (PM) fiber sections configured in series to form 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.