NdYLF

NdYLF refers to a neodymium-doped lithium yttrium fluoride crystal (Nd:YLF), a solid-state laser material based on the LiYF4 host lattice. The Nd3+ ions provide the lasing transitions, while the crystal’s tetragonal, birefringent structure influences polarization and beam quality. Nd:YLF is commonly produced by standard crystal growth techniques and is available with typical doping levels around a fraction of a percent.

The primary laser transitions occur from the 4F3/2 excited state to the 4I11/2 and 4I13/2 manifolds, yielding emission near 1047 nm and 1053 nm, respectively. The crystal’s birefringence makes the emitted light polarization-dependent, which can simplify achieving stable, single-polarization operation. The upper-state lifetime of Nd3+ in LiYF4 is on the order of tens of microseconds, supporting both continuous-wave and pulsed laser configurations.

Nd:YLF is typically pumped with near-infrared diodes in the 802–809 nm range, enabling diode-pumped CW, Q-switched, and mode-locked operation. Compared with Nd:YAG, Nd:YLF generally offers lower emission cross-sections and thermal conductivity, but it provides intrinsic polarization control and narrow, well-defined emission lines that are favorable for line-n narrowing and stable single-frequency lasers.

Applications include diode-pumped solid-state lasers for scientific and industrial use, as well as frequency-doubled green light at around 523.5–526.5 nm for metrology, biomedical instrumentation, and laser displays. Nd:YLF also supports ultrafast laser sources, owing to its favorable pulse-generation characteristics in suitable cavity designs.