Pulsed-laser with first-pulse control

A pulsed-laser, comprising:

• a laser resonator including a gain-medium and a Q-switch for generating laser pulses;
• a pump-light source for energizing said gain-medium;
• said Q-switch having an on-mode in which the Q-switch is substantially transparent, and an off-mode in which the Q-switch is substantially opaque;
• a gate-signal source cooperative with said Q-switch and providing a gate-signal for switching the laser between a ready-mode in which no pulses are generated and a pulse-drive mode in which pulses are generated;
• and
• a first-pulse controller for controlling the energy in a first of a series of pulses generated by the laser, said first-pulse controller operative such that (a) during the ready-mode of the pulsed-laser said Q-switch is substantially opaque, (b) and when the pulsed laser switches from the ready-mode to the pulse-drive mode, the transmission of said Q-switch is raised, (c) and wherein the triggering of said first pulse following said switching of the pulsed laser from the ready-mode to the pulse-drive mode is delayed for a selectable delay-period, said delay-period being selected to be sufficiently long that energy in said-gain-medium falls within said delay-period to a peak level which is reached during the pulse-drive mode, and (d) from the end of said delay-period until switching the pulsed laser back to the ready-mode, transmission of said Q-switch in its off-mode is adjusted to be substantially opaque so that the energy of the first pulse generated in the series does not differ significantly from the successive pulses in the series.

A pulsed-laser, comprising:

• a laser resonator including a gain-medium and a Q-switch for generating a laser beam;
• a pump-light source for energizing said gain-medium;
• said Q-switch having an on-mode in which the Q-switch is substantially transparent, and an oft-mode in which the Q-switch is substantially opaque;
• a gate-signal source cooperative with said Q-switch and providing a gate-signal for switching the laser between a ready-mode in which no pulses are generated and a pulse-drive mode in which pulses are generated;
• and
• a first-pulse controller for controlling the energy in a first of a series of pulses generated by the laser, said first-pulse controller operative such that (a) at the instant of switching the pulsed-laser from the ready-mode to the pulse-drive mode the pump-power is reduced to a limiting value at which losses in the laser exceed the pump-power (b) the triggering of the first pulse after the instant of switching the pulsed-laser from the ready-mode to the pulse-drive mode is delayed for a predetermined delay-period V+T where T is the temporal-separation of pulses in the series of pulses, the value of V being sufficiently long that within time V the energy in said gain-medium falls to zero, and (c) at the end of time V the pump-power is raised to full-power so that the energy of the first pulse generated in the series does not differ significantly from the successive pulses in the series.

A pulsed-laser, comprising:

• a laser resonator including a gain-medium and a Q-switch for generating a laser beam;
• pump-light source for energizing said gain-medium;
• said Q-switch having an on-mode in which the Q-switch is substantially transparent, and an off-mode in which the Q-switch is substantially opaque;
• a gate-signal source cooperative with said Q-switch and providing a gate-signal for switching the laser between a ready-mode in which no pulses are generated and a pulse-drive mode in which pulses are generated;
• and
• a first-pulse controller for controlling the energy in a first of a series of pulses to be generated by the laser, said first-pulse controller operative such that after switching the laser to the pulse-drive mode, the transmission of the Q-switch is increased during a first time-interval so that the energy in said gain-medium is depleted to a start-value which corresponds to the value that would exist in CW operation of the laser, and in a second time interval, immediately following said first time interval, said gain-medium is energized to a peak level which is reached during the pulse-drive mode, and at the end of the second time interval the first laser-pulse is generated so that the energy of the first pulse generated in the series does not differ significantly from the successive pulses in the series.

A pulse-laser, comprising:

• a laser resonator including a gain-medium and a Q-switch for generating laser pulse;
• a pump light source for energizing said gain medium;
• said Q-switch having an on-mode in which the Q-switch is substantially transparent, and an off-mode in which the Q-switch is substantially opaque;
• a gate-signal source cooperative with said Q-switch and providing a gate-signal for switching the laser between a ready-mode in which no pulses are generated and a pulse-drive mode in which pulses are generated;
• and
• a first-pulse controller for controlling the energy in a first of a series of pulses to be generated by the laser, said first-pulse controller operative such that from the instant of switching the pulsed-laser from the ready-mode to the pulse-drive mode, for a predetermined time-interval the transmission of said Q-switch in the on-mode thereof is reduced to a limiting-transmission selected such that the first pulse of a pulse-series delivered following said switching of the pulsed-laser from the ready-mode to the pulse-drive mode has substantially the same energy as subsequent pulses in said pulse-series.