Pulsed laser apparatus and method

A method of generating optical pulses by Q-switching, comprising the steps of:

• providing a reflective gain element comprising first reflective means, an input/output port, a gain medium therebetween and optical pumping means for providing pump radiation into the gain medium for enabling optical gain, for emitting optical radiation from the input/output port along a first optical path;
• providing controllable reflecting/transmitting means disposed in the first optical path having a reflecting state for reflecting a controllable portion of the optical radiation back into the gain medium, a transmitting state for transmitting the optical radiation through the reflecting/transmitting means along the first optical path to form an output optical radiation, and operable to switch between said reflecting state and said transmitting state;
• switching the controllable reflecting/transmitting means from the transmitting state to the reflecting state to form a temporal optical cavity between the first reflective means and the controllable reflective/transmitting means through the gain medium for a duration of time less than a roundtrip time of the controllable portion of the optical radiation in the temporal optical cavity to initiate an optical pulse;
• and,
• switching the controllable reflecting/transmitting means from the reflecting state to the transmitting state for transmitting the optical pulse propagating from the gain element through the controllable reflecting/transmitting means along the first optical path.

A method of generating optical pulses by Q-switching, comprising the steps of:

• providing a reflective gain element comprising first reflective means, an input/output port and a gain medium therebetween, for emitting optical radiation from the input/output port along a first optical path;
• providing optical pumping means for providing pump radiation into the gain medium for enabling optical gain;
• providing controllable reflecting/transmitting means disposed in the first optical path having a reflecting state for reflecting a controllable portion of the optical radiation back into the gain medium, a transmitting state for transmitting the optical radiation through the reflecting/transmitting means along the first optical path to form an output optical radiation, and operable to switch between said reflecting state and said transmitting state;
• switching the controllable reflecting/transmitting means from the transmitting state to the reflecting state to form a temporal optical cavity between the first reflective means and the controllable reflective/transmitting means through the gain medium;
• and,
• switching the controllable reflecting/transmitting means from the reflecting state to the transmitting state for transmitting the optical pulse propagating from the gain element through the controllable reflecting/transmitting means along the first optical path after the optical pulse makes a pre-determined number of round trips in the temporal optical cavity.