Few Cycle Laser Laboratory

Lasers are quickly becoming the most important technology humanity is developing. With lasers we aim to understand the fundamentals of the universe by creating environments only seen in the most extreme environments, all within the safety of Earth.

In my lab group we aim to create some of the shortest pulse lasers in the world. In order to create more powerful lasers we shorten how long the lasers pulse is. In our case we make the pulse about ~6.7 femtoseconds (10^-15 seconds) or 0.0000000000000067 seconds. This means that a smaller energy pulse is much more powerful than if we had the same energy with a pulse of a larger duration.

UCXS (Ultra Compact X-Ray Spectrometer)

Based off a design from the research article “Ultra-compact x-ray spectrometer for high-repetition-rate laser–plasma experiments”, this device aims to help understand the x-rays produced by laser-matter interactions. We measure the X-ray energies by using a series of Aluminum filters with varying thicknesses to determine what is being produced. The after the x-rays are filtered, they hit an Image Plate, which is later scanned and anylised to provide a profile of the x rays produced.

UCXS Electron Deflector

Because an image plate is used to measure the x-ray emissions, special consideration must be given for other particles released during the laser matter interaction. The main one of concern is high energy electrons. These will be much more apparent on the image plate than the x-ray emissions and easily blot them out. To prevent this from happening we designed a magnetic field confined by a ferrous yoke to divert the high energy electrons out of the path of the UCXS.

Oscillator and First Stage Enclosures

In order to have a stable laser, it need to start in a stable environment. The project was an replacement to the previous enclosures in order to have proper isolation from unstable air currents present within the lab. Made from extruded aluminum and black acrylic, this enclosure prevents unwanted air currents from disrupting the laser oscillator.

Saphire Window Holder

A new technology on this laser line is its use of a 4-meter hollow core fiber optic. This fiber optic is then filled with helium gas to broaden the spectrum of the laser pulse. The beam must pass through the fiber optic then into vacuum with minimal distortion. A .5mm thick sapphire window provides the barrier between the ~2 bar of helium to high vacuum.

Electron Dispersion Spectrometer

When lasers interact with matter the laser has so much energy it turns the matter into plasma, and tears the electrons off the atoms of the target. So knowing how dense the electron cloud is and how they are distributed within the cloud can be useful data. This design uses a 5 inch ID aluminum tube milled so only 120 degrees of the ID is being used. This allows for an image plate to be used to measure the dispersion of the laser-matter interaction.

Electron Spectrometer

When energized electrons are produced, it is important to know how much energy they possess, as this can be crucial to understanding what is happening when the laser strikes the target. Electrons of different energies have different speeds. This fact along with the fact that electrons are manipulated by magnetic fields in a circular fashion, means we can measure the speed of the electrons and with that the energy of them. This is done with two magnetics in a permeable steel yoke, that direct the electrons up into an image plate to be measured.