Physics Commons^™

A Jones Calculus Approach To High-Order Harmonic Generation In Solids, Erin Crites, Shima Gholam-Mirzaei, Zain Khan, Mamta Singh, John E. Beetar

The Pegasus Review: UCF Undergraduate Research Journal

High-order harmonics from bulk solids were first observed in 2011 by focusing an intense mid-infrared laser through a bulk crystal and detecting the harmonics in a transmission geometry. Due to birefringence and possible nonlinear effects in bulk crystal, the polarization state of the laser can change as it propagates through the crystal in this transmission geometry. This can result in harmonic signal generated with an unknown polarization of light, disrupting the signal. Alternatives to bulk crystal, such as a reflection geometry or thin films, are not always ideal – reflection geometry can introduce nonlinear reflection coefficients, while crystalline thin films …

Improvement For Generating High-Order Harmonics And Attosecond Pulses With Ultrashort Laser Fields, Dian Peng

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Nonlinear processes of high-order harmonic generation (HHG) produced by ultrashort few-cycle laser pulses possess interesting features which HHG produced by long pulses of many cycles may not have. First, HHG spectra produced by ultrashort pulses are extremely sensitive to the driving pulse waveform, which can be controlled by laser parameters such as carrier-envelope phases (CEPs), time delays or frequency chirps. Second, HHG spectra produced by ultrashort pulses can exhibit broad uneven peaks which are different from usual odd-ordered harmonic peaks that long pulses produce.

Based on the high sensitivity on pulse waveform of HHG spectra produced by ultrashort pulses, we …

Comment On “Universality Of Returning Electron Wave Packet In High-Order Harmonic Generation With Midinfrared Laser Pulses”, M. V. Frolov, N. L. Manakov, Wei-Hao Xiong, Liang-You Peng, J. Burgdörfer, Anthony F. Starace

Anthony F. Starace Publications

In conclusion, we have shown that when the same definition for the HHG yield is used [cf. Eq. (1)], the results of Ref. [1] give the same scaling law found earlier in Refs. [2–5] for wavelengths λ ≤ 2 μm. We note that this latter scaling law can be obtained analytically by using results of the model developed in Ref. [6] for the description of short-pulse HHG spectra. These analytic results as well as new numerical TDSE results for longer wavelengths, λ ≤ 4 μm, will be published elsewhere.

Phase-Matching Optimization Of Laser High-Order Harmonics Generated In A Gas Cell, Julia Robin Miller Sutherland

Theses and Dissertations

Ten-millijoule, thirty-five femtosecond, 800 nm (~40 nm bandwidth) laser pulses are used to study high-order harmonic generation in helium- and neon-filled gas cells of various lengths. Harmonic orders in the range of 50 to 100 are investigated. A semi-infinite cell geometry produces brighter harmonics than cells of sub-centimeter length. In the semi-infinite geometry, the gas occupies the region from the focusing lens to a thin exit foil near the laser focus. Counter-propagating light is used to directly probe where the high harmonics are generated within the laser focus and to investigate phase matching. The phase matching under optimized harmonic generation …