Saturable absorbers

Saturable absorbers
Crytur provides V:YAG and Cr:YAG saturable absorbers

V:Yag

YAG crystals doped with three-valent vanadium V3+ in tetrahedral positions hint at being efficient passive absorbers for lasers operating in the 1.3 µm region. Efficient Q-switching and modelocking has been obtained with a number of active media such as Nd:YAG, Nd:YAP, Nd:KGW, Nd:YVO4 under flash-lamp and diode pumping.

V:YAG plates are available in a wide range of initial transmission values and with diameters between 2–10 mm.

 

 

Material characteristics
Formula V3+:Y3Al5O12
Crystal structure cubic - la3d
Ground-state absorption cross-section at 1064 nm 1.5 x 10-18 cm2
Excited-state absorption cross-section at 1064 nm 3 x 10-19 cm2
Ground-state absorption cross-section at 1338 nm 2.5 x 10-18 cm2
Excited-state absorption cross-section at 1338 nm 4.5 x 10-19 cm2
Ground-state absorption cross-section at 1444 nm 1.8 x 10-18 cm2
Excited-state absorption cross-section at 1444 nm 3 x 10-19 cm2
Recovery time 5 ns
Design
Q-switch diameter  2 – 10 mm
Q-switch thickness  according to requested initial
transmission
Polishing Barrel surface fine ground or polished. Perpendicular or wedged ends. Polishing according to
DIN and MIL standards.
Coatings  Ion assisted mirrors, output couplers, antireflections

 

Application example: Q-switched Nd:YAG-V:YAG microchip laser

      

Cr:YAG

Cr4+:YAG provides a large absorption cross section in the 0.9 - 1.2 micrometer spectral region, which makes it an attractive choice as a passive Q-switch for diode or lamp pumped Nd:YAG, Nd:YLF, Nd:YVO4, Yb:YAG lasers. Cr4+:YAG has a high damage threshold, good thermal conductivity, good chemical stability and is resistant to ultraviolet radiation.

Material characteristics
Formula Cr4+:Y3Al5O12
Crystal structure cubic - la3d
Ground-state absorption cross-section at 1064 nm 4 x 10-18 cm2
Excited-state absorption cross-section at 1064 nm 7 x 10-19 cm2
Recovery time 4 µs
Design
Q-switch diameter 2 – 12 mm
Q-switch thickness  according to requested initial transmission
Polishing Barrel surface fine ground or polished. Perpendicular or wedged ends. Polishing according to
DIN and MIL standards.
Coatings Ion assisted mirrors, output couplers, antireflections