Yttrium aluminum garnet (YAG) belongs to the cubic crystal system, which has good physical and chemical stability and has been widely used in solid-state lasers. Yb-doped YAG crystal, also known as ytterbium doped yttrium aluminum garnet (Yb:Y3Al5O12, Yb:YAG), is a superb laser medium with a wide range of uses.
Yb:YAG crystals are superior to traditional Nd-doped systems as diode pumps. For high power diode pumped lasers and other prospective uses, Yb:YAG crystals are anticipated to take the place of Nd:YAG crystals. Alfa Chemistry is a professional customizer of laser crystals. We'll walk our customers through the online customization procedure for Yb:YAG laser crystals slowly and methodically.
Advantages of Yb:YAG Crystals
Yb3+ ions have a simple electronic structure with only one excited state above the ground state, avoiding thermal effects caused by upconversion and excited state absorption. Yb3+ is well suited for IR InGaAs diode laser pumping between 900 and 980 nm. The simultaneous close absorption and emission wavelengths result in a low thermal load, which significantly increases the slope efficiency to theoretically close to 90%. Therefore, Yb:YAG crystals are considered the most promising fiber material for 1 μm band lasers.
Fig 1. (a) The Yb:YAG bulk crystal and processed source rods. (b) As-grown Yb:YAG SCFs. (Wang T, et al. 2019)
The Czochralski process is what we often use to create Yb:YAG crystals. Yb:YAG crystals that are now on the market are often different colors of cyan, and the color always gets darker as the crystal size increases. The discolouration could be caused by an inert or decreasing environment. For high-power laser application research, we have successfully fabricated colorless and transparent Yb:YAG SCFs by the LHPG method using Yb:YAG bulk crystals with cyan color in oxygen-rich and inert atmospheres.
Advantages:
- High optical quality
- Very low fractional heating
- Very high ramp efficiency
- Wide absorption band
- No excited state absorption or upconversion
- High thermal conductivity, high mechanical strength
Properties of Yb:YAG Crystals
| Optical and Spectral Properties | |
|---|---|
| Laser Transition | 2 F 5/2→2 F 7/2 |
| Photon Energy | 1.93×10-19 J(@1030nm) |
| Laser Wavelength | 1030 nm |
| Emission Cross Section | 2.0×10-20 cm2 |
| Emission Linewidth | 9 nm |
| Fluorescence Lifetime | 1.2 ms |
| Index of Refraction | 1.82 |
| Diode Pump Band | 940 nm or 970 nm |
| Pump Absorption Band Width | 8 nm |
| Thermal Optical Coefficient | 9×10-6/℃ |
| Loss Coefficient | 0.003cm-1 |
| Alfa Chemistry offers Yb:YAG specification | |
| Dimension | Upon customer request |
| Dimension Tolerance | Rods with diameter +0.0/-0.05 mm, L±0.1mm |
| Doping(atm%) | 0.1% ~ 20% |
| Orientation | <111>crystalline direction |
| Flatness | λ/10 @ 632.8nm |
| Surface Quality | 10/5 Scratch/Dig MIL-O-1380A |
| Clear Aperture | > 90% |
| Damage Threshold | 750MW/cm2 at 1064nm, TEM00, 10ns, 10Hz |
| Coating | AR/HR/PR coating upon customer's request |
| Quality Warranty Period | One year under proper use |
Why Choose Alfa Chemistry?
Alfa Chemistry can customize very high quality ytterbium-doped yttrium aluminum garnet Yb:YAG crystals. To guarantee that each crystal meets the requirements of the customer, we use premium starting materials for crystal development, monolithic ingot interferometry, and accurate measurements of Yb content utilizing transmission spectroscopy and fluorescence lifespan measurements.
If you need technical advice, please contact our technical team to learn more about our high-quality services.
Reference
- Wang T, et al. (2019). "The Characteristics of High-Quality Yb:YAG Single Crystal Fibers Grown by A LHPG Method and The Effects of Their Discoloration." RSC Adv. 9: 22567-22575.