Transmittance derived line width and line shift in polycrystalline Nd:YAG

Area of Science:

• Materials Science
• Laser Physics
• Spectroscopy

Background:

• Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) is a crucial laser medium.
• Understanding the temperature-dependent spectral properties of Nd:YAG is essential for laser design and performance optimization.
• Polycrystalline Nd:YAG presents an alternative to single-crystal forms, with potentially different optical characteristics.

Purpose of the Study:

• To investigate the temperature-dependent transmittance, line width, and line shift of polycrystalline Nd:YAG.
• To adapt existing single-crystal models for polycrystalline materials.
• To compare different line width measurement techniques and identify the most suitable method.

Main Methods:

• Temperature-dependent transmittance measurements were performed on 1% and 6% Nd-doped polycrystalline YAG samples.
• Measurements were conducted across a temperature range of 293 K to 473 K.
• A single-crystal line width model was adapted and validated for polycrystalline YAG, with a focus on the transmittance method for ground state line width determination.

Main Results:

• Polycrystalline Nd:YAG exhibits a broader intrinsic line width compared to single-crystal Nd:YAG.
• The transmittance method was identified as the preferred technique for measuring ground state line widths.
• Temperature variations significantly influence the line width and shift of the material.

Conclusions:

• Polycrystalline Nd:YAG possesses broader spectral line widths than its single-crystal counterpart.
• The broader line width in polycrystalline Nd:YAG suggests potential for shorter minimum pulse lengths in mode-locking applications.
• This material offers promising advantages for developing advanced laser systems requiring high-performance mode-locking.