Nd:YLF Lasers (Neodymium-Doped Yttrium Lithium Fluoride)

Neodymium-doped yttrium lithium fluoride (Nd:YLF) is the most common lasing medium for diode-pumped and arc lamp-pumped solid-state lasers. It is birefringent in nature, and its laser transitions occur at 1047 and 1053 nm. Nd:YLF crystal, is very brittle, slightly soluble in water and has a tendency to fracture easily.

Nd:YLF laser has an ability to yield higher pulse energies than Nd:YAG laser for repetition rates of a few kHz. It is mainly used in Q-switched systems owing to its relatively long fluorescence lifetime. As with Nd:YAG lasers, Q-switched Nd:YLF facilitates harmonic generation to produce shorter wavelengths. Nd:YLF lasers can be lamp-pumped or diode-pumped. When compared to Nd:YAG laser, Nd:YLF laser has low thermal conductivity. However, it exhibits weak thermal distortions to achieve high beam quality.

Other significant properties of Nd:YLF laser include:

• Anisotropic thermal expansion
• Longer upper-state lifetime
• High UV transparency
• Low fracture resistance.

Pumping ultrafast Ti:Sapphire chirped-pulse amplifiers is one of the most common applications of Nd:YLF laser.

Laser Properties

Physical and Chemical Properties

Applications

Nd:YLF lasers are suitable for providing pump light to operate other lasers such as the Ti:Sapphire pulsed lasers which are the most preferred illumination source in multiphoton imaging techniques of fluorescence microscopy. It has also been used by some researchers in all-solid-state multiphoton systems, with the help of three-photon excitation mechanism.

Other suitable applications of Nd:YLF lasers include:

• Spectroscopy
• Particle image velocimetry
• Applications that require high pulse energies.

Sources and Further Reading

• Nd:YLF Mode-Locked Pulsed Lasers – Molecular Expressions
• YLF Lasers – RP Photonics