Apparatus for and method of modulating a light source wavelength

A method of controlling a laser system, the method comprising:

• placing an actuator in a first state in which the actuator causes a first burst of one or more pulses of laser radiation produced by the laser system to have a first reference wavelength;
• and
• placing the actuator in a second state in which the actuator causes a next burst of one or more pulses of laser radiation produced by the laser system to have a second reference wavelength different from the first reference wavelength,
• the method further comprising a third step, performed between the step of placing the actuator in the first state and the step of placing the actuator in the second state, of pre-positioning the actuator in an intermediate state which is between the first state and the second state between the first burst and the next burst.

A method of controlling a laser system, the method comprising:

• placing an actuator in a first state in which the actuator causes a first burst of one or more pulses of laser radiation produced by the laser system to have a first reference wavelength;
• and
• placing the actuator in a second state in which the actuator causes a next burst of one or more pulses of laser radiation produced by the laser system to have a second reference wavelength different from the first reference wavelength,
• wherein the step of placing the actuator in the second state comprises computing an optimal control waveform for the actuator to transition from the first state to the second state and causing the actuator to transition from the first state to the second state along a trajectory under control of the optimal control waveform.

A method of controlling a laser system, the method comprising:

• placing an actuator in a first state in which the actuator causes a first burst of one or more pulses of laser radiation produced by the laser system to have a first reference wavelength;
• and
• placing the actuator in a second state in which the actuator causes a next burst of one or more pulses of laser radiation produced by the laser system to have a second reference wavelength different from the first reference wavelength,
• the method further comprising a third step, between the first burst and the next burst of pre-positioning the actuator in a third state which is intermediate the first state and the second state,
• wherein the step of placing the actuator in the second state comprises computing an optimal control waveform for causing the actuator to transition from the first state to the second state along an optimal trajectory.