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Full-Text Articles in Physics
Ultrafast Laser-Induced Damage And The Influence Of Spectral Effects, Jeremy Gulley
Ultrafast Laser-Induced Damage And The Influence Of Spectral Effects, Jeremy Gulley
Jeremy R. Gulley
Numerous studies have investigated the prerequisite role of photoionization in ultrafast laser-induced damage (LID) of bulk dielectrics. This study examines the role of spectral width and instantaneous laser frequency in LID using a frequency dependent multiphoton ionization (MPI) model and numerical simulation of initially 800 nm laser pulses propagating through fused silica. Assuming a band gap of 9 eV, MPI by an 800 nm field is a six-photon process, but when the instantaneous wavelength is greater than 827 nm an additional photon is required for photoionization, reducing the probability of the event by many orders of magnitude. Simulation results suggest …
Frequency Dependence In The Initiation Of Laser-Induced Damage, Jeremy Gulley
Frequency Dependence In The Initiation Of Laser-Induced Damage, Jeremy Gulley
Jeremy R. Gulley
Numerous studies have investigated the role of photoionization in ultrafast laser-induced damage of bulk dielectrics. This study examines the role of spectral width and instantaneous laser frequency in laser-induced damage using a frequency dependent multiphoton ionization model and numerical simulation of an 800 nm laser pulse propagating through fused silica. When the individual photon wavelengths are greater than 827 nm, an additional photon is required for photoionization, reducing the probability of the event by many orders of magnitude. Simulation results suggest that this frequency dependence may significantly affect the processes of laser-induced damage and filamentation.
Simulation And Analysis Of Ultrafast Laser Pulse Induced Plasma Generation In Dielectric Materials, Jeremy Gulley, Sebastian Winkler, William Dennis
Simulation And Analysis Of Ultrafast Laser Pulse Induced Plasma Generation In Dielectric Materials, Jeremy Gulley, Sebastian Winkler, William Dennis
Jeremy R. Gulley
Recent experiments on optical damage by ultrashort laser pulses have demonstrated that the temporal pulseshape can dramatically influence plasma generation in fused silica and sapphire. In this work a modified 3+1D nonlinear Schroedinger equation for the pulse propagation coupled to a rate equation for the plasma density in the dielectric material is used to simulate pulse propagation and plasma formation in a range of dielectric materials. We use these simulations to analyze the influence of pulse-width, pulse-shape and beam geometry on the formation of the electron plasma and hence damage in the bulk material. In particular, when possible, we simulate …