Harmonic generation in solids with direct fiber laser pumping.

Area of Science:

• Solid-state physics
• Attosecond science
• Nonlinear optics

Background:

• High harmonic generation (HHG) is a crucial process for generating short-wavelength light.
• Extending HHG to solid materials offers potential for compact sources and novel applications.
• Semiconductors are promising materials for HHG due to their tunable electronic properties.

Purpose of the Study:

• To investigate high harmonic generation in semiconductor materials.
• To explore the potential of solid-state HHG for attosecond science and spectroscopy.
• To assess the feasibility of using silicon and zinc oxide for efficient harmonic generation.

Main Methods:

• Focusing a Tm fiber laser into silicon and zinc oxide crystals.
• Characterizing the generated high-order harmonics.
• Performing theoretical calculations to predict higher harmonic orders.

Main Results:

• Generation of up to the seventh harmonic of the Tm fiber laser.
• Observed strong and stable harmonic signals without material damage.
• Calculations indicate potential for generating the nineteenth harmonic (12 eV photons).

Conclusions:

• High harmonic generation in solids is feasible and efficient in silicon and zinc oxide.
• This technique offers a simple source for vacuum ultraviolet frequency comb spectroscopy.
• Further research can explore higher harmonic orders and other solid materials for advanced applications.