Cr4:YAG Passive Q-Switch Crystals
Cr4+:YAG crystals have several advantages when compared to traditional Passive Q-switching choices such as organic dyes and colour centres materials. Crystal Passive Q-switch is preferred for simplicity of manufacturing and operation, low cost, and reduced system size and weight. Cr4+:YAG is chemically stable, UV resistant and it is durable. Cr4+:YAG will operate over a wide range of temperatures and conditions. The good thermal conductivity of Cr4+:YAG is well suited for high average power applications.
Excellent results have been demonstrated using Cr4+:YAG as a passive Q-switch for Nd:YAG lasers. The saturation fluence was measured to be approximately 0.5 J/cm2. The slow recovery time of 8.5 µs, as compared to dyes, is useful for the suppression of mode locking. Q-switched pulsewidths of 7 to 70 ns and repetition rates of up to 30 Hz have been achieved. Laser Damage Threshold tests showed AR coated Cr4+:YAG passive Q-switches exceeded 500 MW/cm2.
The optical quality and homogeneity of Cr4+:YAG is excellent. To minimise insertion loss the crystals are AR coated. Cr4+:YAG crystals are offered with a standard diameter, and a range of optical densities and lengths to match your specifications.
Optical Properties and Dimensions
|0 mm / +0.05 mm|
|Typical Length||2 mm to 10 mm|
|Parallelism||30 arc-sec. max|
|Flatness||λ/2 at 632 nm Max.|
|Refractive Index||1.82 at 1.064µm|
|Standard Optical Densities||0.40 +/- 10%|
|0.50 +/- 10%|
|0.60 +/- 10%|
|1.00 +/- 10%|
|Saturation Fluence||near to 0.5 J/cm2|
|Recovery Time||8.5 µs|
|Repetition Rate||> 30 Hz|
|AR coating||0.3% per surface|
|Damage Threshold||> 500 MW/cm2|
|Orientation||<111 > cubic|