A laser system comprising at least one Pockels cell comprising the driver circuit as claimed in claim The difference of these two voltage values is a function of the parameters of the crystal material that is used and the wavelength of the propagating laser beam to be switched. Pockels cell driver circuit for rapidly varying the pulse amplitude of short or ultrashort laser pulses. Tunable passively mode-locked lasers with phase-lock feedback for low timing jitters. In some applications both transitions from high to low voltage and vice versa must take place within a few nanoseconds, while some other applications only require one of the transitions to be as fast as a few nanoseconds, whereas the other transition can take place also in a time of microseconds. One or both of the edges may deliberately be slowed down for this purpose.
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This example shows the falling edge 55 to be slower than the rising edge 54 of the voltage pulse. Extrusions and corner brackets for a screen frame of a rear projection display. Some aspects of cepl invention feature a controllable Pockels cell system that allows for a particularly fast amplitude variation of laser pulses. The delay unit can be connected to the push-pull-circuit, and can include an input port for a trigger single and a first and a second output port for control signals, with the first output port connected to the first switch and the second output port connected to the second switch.
In this case the laser pulse passes the Pockels cell at the instant of maximum transmission T maxleaving it with the maximum pulse energy E max. These edges can be deliberately slowed down, for example more than 15 ns, to reduce the effect of unavoidable jitter in the synchronization of laser pulse with voltage pulse by reducing the slope of the voltage versus time function.
Our Pockels ccell drivers include the Q-series Q-switch drivers and R-series regenerative amplifier drivers. A high repetition rate laser system with such as amplitude control for individually plckels laser pulses can favorably be used for material processing, such as drilling holes or grooves with single laser pulses, specifically with respect to their depths or widths, etc.
This well defined transmission versus time function will be applied synchronously with the impinging laser pulses to the Pockels cell, synchronous to every laser pulse, for example, to every celp laser pulse or to every nth laser pulse.
US20080018977A1 – Controlling pockels cells – Google Patents
The difference of these two voltage values is a function of the parameters of the crystal material that is used and the wavelength of the propagating laser beam to be switched.
The main pulse that has been selected by the external electro-optical modulator 5 e leaves the optical path through polarizer 4 e at port A and is directed to a workpiece A Pockels cell normally comprises a birefringent crystal, which is suitably oriented with respect to the propagating light beam and to which a voltage of a few hundred to a few thousand volts is applied for changing the polarization of the incident light beam.
Since the polarizer 4 b can never be perfect, before the amplified pulse is extracted from the resonator, there will be a pulse train of pre-pulses leaking through this polarizer, with each amplified pulse reflected back. Using acousto-optical modulators, the switching time is determined by the speed of sound and the diameter of the laser beam. The amplitude may be controlled by temporal coincidence of the voltage pulse applied to the Pockels cell with the arriving laser pulse.
Thorald Horst Bergmann Inventions, Patents and Patent Applications – Justia Patents Search
The Pockels cell 22 is switched on by closing the first switch S 1 B and opening the second switch S 1 A, and the Pockels cell 22 is switched off by operating the third and fourth switches S 2 B and S 2 A.
The corresponding time on the x-axis was then calculated from the temporal delay between laser pulse and Pockels cell pulse. Like in the system of FIG.
However, the gain medium can likewise have an intrinsically high gain, in which case, however, owing to the external constitution, the gain achievable during operation in the case of a single pass through the gain medium has only relatively low values.
In accordance with a third aspect, the present disclosure relates to a laser system comprising at least one Pockels cell in accordance with the second aspect.
CROSS REFERENCE TO RELATED APPLICATION
One of these laser pulses is selected by temporal coincidence of its arrival at the electro-optical modulator with the edges of the control voltage pulse of the Pockels cell. This laser beam is focused onto the surface with a mirror that is placed as close as possible to the analysed surface. A rising edge of the high voltage pulse is produced by simultaneously closing the first switch S 1 B and opening the second switch S 1 A, applying the high voltage to the Pockels cell Such a decrease in the optical contrast can have a disadvantageous effect on optical systems, in particular laser amplifiers, for example.
The resonant circuit has a third resistance R 3a capacitance 03 and an inductance L 1. Method and apparatus for controlling and protecting pulsed high power fiber amplifier systems.
USA1 – Controlling pockels cells – Google Patents
Graph b of FIG. The evaporated material passes through a opening in the mirror into the mass spectrometer. The Faraday rotator 7 a, half-wave plate 7 b and polarizer 4 a thus form an optical diode. The QDP-drive produces a double-pulse waveform that holds off lasing during flash lamp operation and pulses the Pockels cell at peak gain inversion— when laser output is at maximum — then applies voltage again to turn the Pockels cell off and prevent additional laser pulses from being emitted.
This node is connected to a second potential, such as a ground terminal, via a second switch. This allows displacing in time the pockeels pulse applied to the Pockels cell, in this manner also displacing in time the transmission pulse of the Pockels cell with an analyzer located behind the Pockels cell.
The system of claim 3wherein the delay unit is connected to both the first switch and the second switch, and wherein the delay unit receives a trigger signal and generates plckels control signals to the first and second switches with individually controllable time delays for each control signal. HV via a second resistance R2 ; and wherein the first node J1 is connected to the second node J2 via a series circuit comprising a third resistance R3 and an inductance L1.
The second delay unit 23 is connected to the third and fourth switches S 2 B and S 2 A of the second push-pull circuit 21 b.