A High Power, Solid State and Compact Passive Q-switch Cr4+: YAG (Y3Al5O12 ) is an excellent crystal for passively Q-switching diode pumped or lamp-pumped Nd: YAG, Nd: YLF, Nd: YVO4 or other Nd and Yb doped lasers at wavelength from 0.8 to 1.2μm.  Because of its high damage threshold (<500 MW/cm2) and being easy to be operated, it will replace LiF and Dye which are commonly used as passive Q-switching materials.

The preliminary experiments of Dream Lasers' Cr: YAG showed that the pulse width of passively Q-switched lasers could be as short as 5ns for diode pumped Nd: YAG lasers and repetition as high as 10kHz for diode pumped Nd: YVO4 lasers. Furthermore, an efficient green output @ 532nm, and UV output @ 355nm and 266nm were generated, after a subsequent intracavity SHG in KTP or LBO, THG and 4HG in LBO and BBO for diode pumped and passive Q-switched Nd: YAG and Nd: YVO4 lasers.

Cr: YAG is also a laser crystal with tunable output from 1.35μm to 1.55μm.  It can generate ultrashort pulse laser (to fs pulsed) when pumped by Nd: YAG laser at 1.064μm.

Dream Lasers provides Cr4+: YAG with Cr4+ doping level from 0.5mol% to 3mol%.  The size could be from 2x2mm2 to 14x14mm2 with length from 0.1mm to 12mm available.  We can control the initial transmission from 1% to 99% according to customers’ requirements.

Basic Properties of Cr4+ YAG
Formula: Cr4+: Y3Al5O12
Crystal Structure: Cubic Garnet
Density: 4.56g/cm3
Hardness: 8.5 (Mohs)
Damage Threshold: >500 MW/cm2
Refractive Index: 1.82 @ 1064nm
Thermal Conductivity: 12.13w/m/k
Main Specifications
Flatness: < λ/8
Wavefront Distortion: < λ/4
Parallelism: < 30”
AR-Coating: R <0.2% @ 1064nm

New! Cr4+: YAG crystal has been demonstrated as a Self-Pumped Phase-conjugate Mirror in a Nanosecond Nd: YAG high power loop resonator.  It compensates not only for phase aberrations, but also for polarization aberrations induced into the loop resonator.