Sang June Yoon

Learn More
Articles you may be interested in Dependence of electron trapping on bubble geometry in laser-plasma wakefield acceleration Self-truncated ionization injection and consequent monoenergetic electron bunches in laser wakefield acceleration Phys. Enhancement of injection and acceleration of electrons in a laser wakefield accelerator by using an argon-doped(More)
A laser pulse propagating in a corrugated plasma channel is composed of spatial harmonics whose phase velocities can be subluminal. The phase velocity of a spatial harmonic can be matched to the speed of a relativistic electron resulting in direct acceleration by the guided laser field in a plasma waveguide and linear energy gain over the interaction(More)
We present the first multi-Watt demonstration of a diode pumped cryogenically cooled neodymium-doped yttrium aluminum garnet (YAG) laser operating at 946 nm on the (4)F(3/2) → (4)I(9/2) transition. 3.8 W of continuous wave output power for 12.8 W of absorbed pump was obtained with a slope efficiency of 47%. In addition, we made an extensive characterization(More)
The accurate determination of burn depth is critical in the clinical management of burn wounds. Polarization-sensitive optical coherence tomography (PS-OCT) has been proposed as a potentially non-invasive method for determining burn depth by measuring thermally induced changes in the structure and birefringence of skin, and has been investigated in(More)
We demonstrate the generation of axially modulated plasma waveguides using spatially patterned high-energy laser pulses. A spatial light modulator (SLM) imposes transverse phase front modulations on a low-energy (10 mJ) laser pulse which is interferometrically combined with a high-energy (130-450 mJ) pulse, sculpting its intensity profile. This enables(More)
Plasma guiding structures are generated with programmable axial density modulations using a Spatial Light Modulator (SLM). A coherent beam-combining scheme enables the sculpting of high power beams with modest energy passing through the SLM.
The energy gain in laser wakefield acceleration is ultimately limited by dephasing, occurring when accelerated electrons outrun the accelerating phase of the wakefield. We apply quasi-phase-matching, enabled by axially modulated plasma channels, to overcome this limitation. Theory and simulations are presented showing that weakly relativistic laser(More)
We examine the generation of axially modulated plasmas produced from cluster jets whose supersonic flow is intersected by thin wires. Such plasmas have application to modulated plasma waveguides. By appropriately limiting shock waves from the wires, plasma axial modulation periods can be as small as 70 μm, with plasma structures as narrow as 45 µm. The(More)