Described herein are methods for developing and maintaining pulses that are produced from compact resonant cavities using one or more Q-switches and maintaining the output parameters of these pulses created during repetitive pulsed operation. The deterministic control of the evolution of a Q-switched laser pulse is complicated due to dynamic laser cavity feedback effects and unpredictable environmental inputs. Laser pulse shape control in a compact laser cavity (e.g., length/speed of light <˜1 ns) is especially difficult because closed loop control becomes impossible due to causality. Because various issues cause laser output of these compact resonator cavities to drift over time, described herein are further methods for automatically maintaining those output parameters.

Described herein are methods for developing and maintaining pulses that are produced from compact resonant cavities using one or more Q-switches and maintaining the output parameters of these pulses created during repetitive pulsed operation. The deterministic control of the evolution of a Q-switched laser pulse is complicated due to dynamic laser cavity feedback effects and unpredictable environmental inputs. Laser pulse shape control in a compact laser cavity (e.g., length/speed of light <˜1 ns) is especially difficult because closed loop control becomes impossible due to causality. Because various issues cause laser output of these compact resonator cavities to drift over time, described herein are further methods for automatically maintaining those output parameters.

Provided is a multiple laser pulse oscillation method using multiple Q-switching capable of reducing peak power of laser and increasing energy efficiency. A multiple laser pulse oscillation method using multiple Q-switching includes: forming one period of light energy; exciting electrons of a gain medium by the light energy; performing first Q-switching during one period of the light energy; oscillating a first laser pulse by the first Q-switching; performing second Q-switching during one period of the light energy; and oscillating a second laser pulse by the second Q-switching.

Provided is a multiple laser pulse oscillation method using multiple Q-switching capable of reducing peak power of laser and increasing energy efficiency. A multiple laser pulse oscillation method using multiple Q-switching includes: forming one period of light energy; exciting electrons of a gain medium by the light energy; performing first Q-switching during one period of the light energy; oscillating a first laser pulse by the first Q-switching; performing second Q-switching during one period of the light energy; and oscillating a second laser pulse by the second Q-switching.

A Q-switched CO2 laser material processing system with acousto-optic modulators (AOM) is employed, on the one hand, inside the resonator for Q-switching the CO2 laser and, on the other hand, externally for efficient suppression of the radiation feedback between a laser and workpiece. The frequency shift of the radiation diffracted at the AOM is taken into account which exactly corresponds to the excitation frequency of the acoustic wave in the AOM crystal under the aspect of the amplification of the radiation in the active medium. Since this frequency shift significantly reduces the amplification of the radiation, it has to be avoided in the Q-switching process, which is achieved, by means of a tandem of two AOMs with identical excitation frequencies but with the acoustic waves propagating in opposite directions in the crystal. The frequency shift advantageously suppresses radiation feedback between the laser and workpiece.

A Q-switched CO2 laser material processing system with acousto-optic modulators (AOM) is employed, on the one hand, inside the resonator for Q-switching the CO2 laser and, on the other hand, externally for efficient suppression of the radiation feedback between a laser and workpiece. The frequency shift of the radiation diffracted at the AOM is taken into account which exactly corresponds to the excitation frequency of the acoustic wave in the AOM crystal under the aspect of the amplification of the radiation in the active medium. Since this frequency shift significantly reduces the amplification of the radiation, it has to be avoided in the Q-switching process, which is achieved, by means of a tandem of two AOMs with identical excitation frequencies but with the acoustic waves propagating in opposite directions in the crystal. The frequency shift advantageously suppresses radiation feedback between the laser and workpiece.

Disclosed herein is a single pulse laser apparatus that includes: a resonator having a first mirror, a second mirror, a gain medium, an electro-optic modulator (EOM) configured to perform single pulse switching, and an acousto-optic modulator (AOM) configured to perform mode-locking; a photodiode configured to measure a laser beam oscillated in the resonator; a synchronizer configured to convert an electrical signal, which is generated by measuring the laser beam, into a transistor-transistor logic (TTL) signal; a delay unit configured to set a delay time for the TTL signal to synchronize the EOM and the AOM and output a trigger TTL signal according to the delay time; an AOM driver configured to input the trigger TTL signal to the AOM that performs mode-locking and drive the AOM; and an EOM driver configured to input the trigger TTL signal to the EOM that performs single pulse switching and drive the EOM.

Disclosed herein is a single pulse laser apparatus that includes: a resonator having a first mirror, a second mirror, a gain medium, an electro-optic modulator (EOM) configured to perform single pulse switching, and an acousto-optic modulator (AOM) configured to perform mode-locking; a photodiode configured to measure a laser beam oscillated in the resonator; a synchronizer configured to convert an electrical signal, which is generated by measuring the laser beam, into a transistor-transistor logic (TTL) signal; a delay unit configured to set a delay time for the TTL signal to synchronize the EOM and the AOM and output a trigger TTL signal according to the delay time; an AOM driver configured to input the trigger TTL signal to the AOM that performs mode-locking and drive the AOM; and an EOM driver configured to input the trigger TTL signal to the EOM that performs single pulse switching and drive the EOM.

Provided is a single pulse laser apparatus. The apparatus including a resonator having a first mirror, a second mirror, a gain medium, and electro-optic modulators (EOMs) which perform each mode-locking and Q-switching, the apparatus includes a photodiode which measures laser light that oscillates from the resonator, a synchronizer which converts an electrical signal generated by measuring the laser light into a transistor-transistor logic (TTL) signal, a delay unit which sets a latency determined in order to synchronize a mode-locked pulse with a Q-switched pulse to the TTL signal, and outputs a trigger TTL signal according to the latency, and a Q-driver which inputs the trigger TTL signal to the EOM which performs Q-switching, and causes the EOM to operates.

An apparatus (such as a laser-based system) and method for providing optical pulses in a broad range of pulse widths and pulse energies uses a pulse slicer which is configured to slice a predefined portion having a desired pulse width of each of the one or more output optical pulses from a laser oscillator, in which timings of a rising edge and a falling edge of each sliced optical pulse relative to a time instance of a maximum of the corresponding each of the one or more output optical pulses from the laser oscillator, are chosen at least to maximize amplification efficiency of the optical amplifier, which may be located after the pulse slicer, and to provide the one or more amplified output optical pulses each having the desired pulse energy and pulse width.