A high transmission for the laser pulse can be achieved by positioning the voltage pulse such that the voltage maximum coincides with the incoming laser pulse. A method for generating bursts of laser pulses comprising generating first repetition rate laser pulses, and generating first repetition rate laser bursts from the repetition laser pulses, the laser bursts each containing a sequence of second repetition rate laser pulses, wherein the second repetition rate is higher than the first repetition rate. This type of low-gain, regenerative amplifier, controllable Pockels cell system can be particularly advantageous as compared to an acousto-optical modulator. If the delay unit is connected to the second push-pull circuit, the first output port is connected to the third switch and the second output port is connected to the fourth switch. Such an electro-optical modulator with a Pockels cell and a switchable high voltage supply can be used to optically switch laser pulses of short duration such as a few nanoseconds ns , or ultrashort duration such as picoseconds ps or femtoseconds fs , either changing their intensity or their propagation path. DE 51 B4 discloses an electrical control for Pockels cells and a laser system employing a Pockels cell with such an electrical control for selecting laser pulses.
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Another aspect of the invention features a laser system for producing short or ultrashort laser pulses. The laser system as claimed in claim 6further comprising a regenerative amplifier comprising a resonator, in a beam path of which a gain medium and the Pockels cell are arranged.
US20080018977A1 – Controlling pockels cells – Google Patents
Thus, by using two delay units, the switching times of all four switches may be modified by analog signals with individually set and controlled delays. This switch can either replace the commonly used recharging resistor or be placed in parallel to it.
The voltage is applied to or removed from the Pockels cell 22 by operating the first and second switches S 1 B and S 1 A and likewise the third and fourth switches S 2 B and S 2 A in a push-pull manner, such as by simultaneously closing switch S 1 B and opening switch S 1 A, simultaneously closing switch S 1 A and opening switch S 1 B, or by simultaneously closing switch S 2 B and opening switch S 2 A, simultaneously closing switch S 2 A and opening switch Ppockels 2 B.
In this way, it is not possible to control the amplitude of consecutive laser pulses, which is desired for certain applications such as material processing.
CROSS REFERENCE TO RELATED APPLICATION
This improves upon some known Pockels cell systems by providing means for modifying the switching time when the high voltage is applied to the Pockels cell. This allows displacing in time the voltage pulse applied to the Pockels cell, in this pockel also displacing in time the transmission pulse of the Pockels cell with an analyzer located behind the Pockels cell.
Mode-locked laser pulses usually have high repetition rates above 1 MHz, typically from 40 MHz to MHz, for solid state lasers, and low pulse energies in the order of nanojoules, typically from 0. This laser system is equipped with an electro-optical modulator as discussed above. In accordance with one exemplary embodiment of the driver circuit 40 in FIG.
Commonly used devices for switching laser pulses are optical switches or modulators placed in the beam path within ppockels outside of a laser resonator. The laser system of claim 13, wherein the laser amplifier comprises a regenerative laser amplifier.
BME – Bergmann Messgeraete Entwicklung: Pockels Cell Drivers
The voltage pulse corresponds to a transmissivity pulse for the laser beam that passes an analyzer positioned behind or downstream of the Pockels cell Thus, by using two delay units, the switching times of all four switches may be modified by analog signals with individually set and controlled delays. A driver circuit, comprising a first node, which is connected to a first terminal of a Pockels cell; and.
Other features, objects, and advantages of the invention will be apparent from the hme and drawings, and from the claims. In this case, the extracted mode-locked laser pulses are injected into an optical amplifier, passing its amplifying stage the number of times necessary to achieve the desired energy level. This laser pulse 41 at time t b with energy E Pockls is to be selected by the Pockels cell 12 and 22 and its amplitude is to be set to the desired value by the Pockels cell system 10 and Options for enhanced reliability include complex voltage traces to avoid crystal degradation, custom triggering logic with precisely controlled delays to prevent damage and custom interfaces for remote control.
For switching short and ultrashort laser pulses the transmission versus time function should be slow enough to be essentially constant during the time span of the laser pulse. DE A1, the contents of which are incorporated herein by reference.
YAG—that is to say actually a high-gain material—in the case of an embodiment in the form of thin plates the single-pass gain may be only in the range of 1.
A laser beam source generates laser pulses having defined polarization, energy, wavelength and pocke,s rate. In accordance with a second aspect, the present disclosure relates to a Pockels cell comprising a driver circuit in accordance with the first aspect.
The system of claim 7wherein pokcels first push-pull circuit comprises a first switch connected to both a first potential and a first node, and a second switch connected to both a second potential and the first node; wherein the second push-pull circuit comprises a celo switch connected to both the first potential and a second node, and a fourth switch connected to ppckels the second potential and the second node.
Thus it is possible to individually control the amplitude of selected laser pulses. The first and second delay units 13 and 23 generate control signals with individually controllable time delays for each control signal.
Alternatively this can also be done by adding capacitance to the circuit or by increasing the self-capacitance of the switch S 1 A or the capacitance of the Pockels cell The delay unit can be connected to the push-pull-circuit, and can include an input port for a trigger single bem a first and a second output port for control signals, with the first output port connected to the first switch and the second output pockes connected to the second switch.
This amplifier can by of any type, linear or regenerative. High-voltage switch with a cooling device. Carrier-envelope-phase stabilized chirped-pulse amplification system scalable to higher pulse energies.
A controllable Pockels cell system comprising a Pockels cell; and. The delay unit can have an input port for a trigger signal and first and second output ports for control signals.