High-Voltage switch controlled by LASER pulse

[pierebean]

Hello,

I wish to switch ON and OFF a high-voltage (that generates a high electric field) using a ultra-fast laser as a trigger.

Basically I have a flow of charged particles that I want to quickly deflect using an E-field. The timing must be correct and controlled by a LASER.

Does anyone know some way to achieve this scheme?

I know there are some pretty fast pulsed laser (picosecond? nanosecond?) can these frequencies "tranduce" a high voltage? Is there an intrinsic upper limit in term of frequency for the High-voltage switch?

Help will be much appreciated.

 

[Bobbywhy]

pierebean, Your project sounds interesting. Surely some members here will be ready and willing to assist you with making it function. Will you please clearly describe your apparatus with more detail? This will help others who wish to contribute suggestions towards its realization.

Modern lasers can emit ultra short pulses, and with some techniques even femtosecond pulses may be developed. Your post title mentioned there was some high voltage switch that would be controlled by the laser. That appears to be a viable proposal.

1. Do you have a high voltage source? What voltage is it?
2. Do you need to turn on and also turn off the source with the laser?
3. What means “can these frequencies “transduce” a high voltage?” Are you proposing to generate some high voltage with the laser pulse?
4. What does “intrinsic upper limit in term of frequency for the HV switch” mean?

Just for your information, you aren’t the first to do this:
A STUDY OF PICOSECOND, HIGH-VOLTAGE PHOTOCONDUCTIVE SWITCHING USING ELECTROOPTIC DIAGNOSTICS AND COMPUTER-AIDED ANALYSIS
by
Lawrence Eric Kingsley
Submitted in Partial Fulfillment of the Requirements for the Degree
DOCTOR OF PHILOSOPHY
Abstract
This dissertation documents advances in the field of ultrafast, high-voltage, semiconductor photoconductive switching. New developments in experimental diagnostics and theoretical device simulation are presented. The output waveform of a laser-activated silicon photoconductive switch in a coaxial circuit was measured for bias voltages up to 20 kV. The switch was activated with a -150 ps laser pulse.
www.lle.rochester.edu/media/publications/.../Kingsley.pdf
++++++++++++++++++++++++++++
Laser-triggered high-voltage plasma switching with diffractive optics
www.opticsinfobase.org › ... › Volume 40 › Issue 16
+++++++++++++++++++++++++++++++++++++
Cheers,
Bobbywhy

 

[pierebean]

Thank you Bobbywhy for your prompt response,

At the moment the apparatus is at an early stage. Before continuing further, I just want to how if it was feasible and preferential commercially available or even better "cheaply makeable".

I have a vacuum chamber with an electron source. On the other end of my chamber I have an electron detector. When I apply the high-voltage, the electrons flow along the chamber to my detector. I wish to prevent them to reach the detector at a certain time. This time need to be at the same frequency of the LASER beat.

For instance, if the LASER beat at 1 kHz. Then the detector will received an electron stream of 1kHz. I cannot use a mechanical shutter because the frequency is too low.

I read about femtosecond laser used in chemistry for pump&probe techniques. Although the pulse is short, I am not sure of the minimum usual beating frequency. Is it GHz THz ?

Here are some more information:

1) I do have a home-made (not by me) high-voltage source. I wish to work between 1kV up to 10kV but the less than 5kV is fine.
2) Perhaps it is not necessary to turn off and on the voltage. A simple modulation would be enough to deflect the electron beam enough so it could not reach the detector.
3) No, I meant to ask if it was possible to modulate or trigger the high-voltage using the Laser as a reference frequency.
4) I meant to ask if there was a physical upper limit (for the frequency) above which an electric field could not be turned ON and OFF. For instance, a don't think I could modulate my electron flux at say 1e14 Hz. I was just wondering what was the physical highest frequency I could achieve in theory.

Anyway, I'll have a look at the dissertation. Thank you so much for that and the article. It seems that my Google searchs were not powerful enough. It is an art after all!

Qapla'

 

[berkeman]

What is your high voltage source? HV power sources don't generally turn on and off very quickly. You can generate HV pulses in the 10kHz-100kHz range using a flyback topology, and you could even vary the frequency of the pulses a bit, but that doesn't sound like what you want.

Using a laser beam or a fiberoptic system to act as a trigger should be no problem. You just need a fast detector, like a PIN photodiode with good reverse bias and a current-to-voltage converter stage to give you a control signal.

 

[alphy]

Thank you for your interest in using a high-voltage switch controlled by a laser pulse. This is a fascinating and innovative idea that has potential in various scientific and technological applications. The use of an ultra-fast laser as a trigger for switching high-voltage is a promising concept that has been explored by researchers in the field of plasma physics and high-voltage engineering.

To answer your questions, yes, it is possible to use a picosecond or nanosecond pulsed laser to trigger a high-voltage switch. These ultra-fast lasers are capable of generating short pulses of intense light, which can be used to create a high-voltage electric field. The timing and control of the laser pulse can be adjusted to accurately switch the high-voltage on and off, providing precise control of the charged particles.

There is no intrinsic upper limit in terms of frequency for the high-voltage switch. The frequency of the laser pulse can be adjusted to match the switching speed required for your specific application. However, it is important to consider the limitations of the materials and components used in the high-voltage switch, as they may have a maximum operating frequency.

Overall, the use of a laser pulse to control a high-voltage switch is a promising approach that has potential in various fields, such as plasma physics, high-voltage engineering, and particle acceleration. I hope this information helps and I wish you success in your research.