Tailored nonlinear optics for particle acceleration and environmental sensing

This proposal concerns research in nonlinear optics using the backward-wave optical parametric oscillator (BWOPO) - a unique device developed in our laboratory.

It is a quasi-phase-matched, nanodomain-engineered crystal which, when pumped with an intense laser beam, generates a narrow-linewidth, frequency stable, contra-directional, down-converted beam and a collinear beam that inherits the spectrum of the pump.With the BWOPO we will demonstrate novel physical phenomena and devices by providing previously unavailable functionality.

We will develop sources of record-high mid-infrared THz pulses. They will be used to drive a chip-based particle accelerator. It consists of an electron beam from an electron microscope launched through a microstructured diamond chip. The chip is pumped with the THz radiation and the electron bunches will be accelerated to MeV energies.

By colliding the electron beam with a laser we will get high-brightness radiation covering the x-ray to far-IR spectrum.

It will have applications in radiation therapy, material science, and more.We will also use the BWOPO as a novel light source for environmental gas sensing.

The backward beam is perfectly suited for differential absorption lidar due to its narrow linewidth, easy tuning, and high stability.

With research partners, we will do precise and continuous monitoring of atmospheric CO2 and other greenhouse gases in different biotopes, which will be valuable for enhancing our understanding of climate change.