Laser modulation for coagulation

An apparatus comprising:

• a pump module providing pump energy;
• a resonator comprising:
• a gain medium receiving the pump energy from the pump module and producing light;
• at least two at least partially reflective surfaces reflecting light produced by the gain medium back toward the gain medium;
• a variable light attenuator receiving light produced by the gain medium;
• a controller that provides a driver signal to the variable light attenuator to control the amount of light attenuated by the variable light attenuator such that the apparatus emits windows of pulses of laser light at spaced time intervals, each window containing a plurality of pulses of laser light and each interval between windows being larger than an interval between pulses within a window, the duration of the windows and the duration of the intervals between windows being such that the emitted windows of pulses of laser light heat tissue to a temperature that causes coagulation, wherein the provided driver signal is at a first magnitude during the intervals between windows, transitions to a second magnitude to cause the apparatus to emit a first pulse of laser light of a window, and alternates between the first magnitude and a third magnitude to cause the apparatus to emit pulses of laser light of the window other than the first pulse of laser light, wherein the difference between the first magnitude and the third magnitude is greater than the difference between the first magnitude and the second magnitude.

A method comprising:

• receiving an input indicating that a medical laser system is to be placed in a vaporization mode;
• based on the input indicating that the medical laser system is to be placed in the vaporization mode, controlling the medical laser system so that the medical laser system emits a continuous series of micropulses of laser light;
• receiving an input indicating that the medical laser system is to be placed in a coagulation mode;
• and
• based on the input indicating that the medical laser system is to be placed in a coagulation mode, controlling the medical laser system so that the medical laser system emits a series of macropulses of laser light, each macropulse comprising a series of micropulses of laser light and the macropulses in the series separated by a time interval that is longer than a time interval between micropulses within a macropulse, wherein controlling the medical laser system so that the medical laser system emits a series of macropulses of laser light comprises controlling a q-switch in the medical laser system by providing a driver signal to the q-switch that transitions from a first magnitude to a second magnitude and back to the first magnitude to trigger a first micropulse of laser light in a macropulse and transitions from the first magnitude to a third magnitude and back to the first magnitude for other micropulses of laser light in the macropulse.