Pr:YLF laser

A Pr:YLF laser (or Pr3+:LiYF4 laser) is a solid state laser that uses a praseodymium doped yttrium-lithium-fluoride crystal as its gain medium. The first Pr:YLF laser was built in 1977 and emitted pulses at 479 nm. Pr:YLF lasers can emit in many different wavelengths in the visible spectrum of light, making them potentially interesting for RGB applications and materials processing. Notable emission wavelengths are 479 nm, 523 nm, 607 nm and 640 nm.

Technology

Pr:YLF lasers are optically pumped using flashlamps, pulsed dye lasers or diode lasers. The strongest emission line of Pr:YLF is 640 nm, which stems from the

3

P

0

→

3

F

2

{\displaystyle ^{3}P_{0}\rightarrow \ ^{3}F_{2}}

transition of the Pr3+- ion. However, by suppressing this line (and other lines stronger than the desired one), other transitions can be used for obtaining different wavelengths. This can be done using dichroic mirrors. Pr:YLF lasers are pumped by using the transitions from

3

H

4

{\displaystyle ^{3}H_{4}}

to

3

P

2

{\displaystyle ^{3}P_{2}}

,

3

P

1

{\displaystyle ^{3}P_{1}}

or

3

P

0

{\displaystyle ^{3}P_{0}}

(corresponding wavelengths: 444 nm, 469 nm, 479 nm). The Pr3+- ion then undergoes a quick, radiationless transition (fast relaxation), followed by the light-emitting transition.