Yb:CALGO, also known as Ytterbium Doped Calcium Gadolinium Aluminate (Yb), represents a promising advancement in laser gain materials with exceptional properties. Its tetragonal crystal structure enables broad emission spectra from 994 nm to 1050 nm under σ configuration when pumped at 979 nm in π configuration, resulting in an ultra-low quantum defect of 1.5%. Yb:CALGO is ideal for generating ultra-fast pulses and is characterized by high thermal conductivity up to 6.7 W/m/K, making it well-suited for high-power laser applications.

Key Features:

• Ultra-low quantum defect (down to 1.5%)
• Broad emission range: 994 nm to 1050 nm
• High thermal conductivity: up to 6.7 W/m/K
• High absorption coefficient @979 nm
• High stimulated emission cross section
• Low laser threshold
• High slope efficiency with diode pumping (up to 55%)
• Various Yb-doping concentrations available

Applications:

• Achieves over 5.5 W output power with a 23 W incident pumping diode laser and 10% output coupler
• Reported output power up to 12.5 W and 94 fs pulses with 28 W pumping power

Basic Properties (Table 1):

• Crystal Structure: Tetragonal
• Lattice Parameter: a = 3.6585 Å, c = 11.978 Å
• Melting Point: 1850 °C
• Mohs Hardness: 6 Mohs
• Density: 4.8 g/cm³
• Thermal Conductivity: K[001] = 6.3 W/m/K, K[100] = 6.9 W/m/K
• Thermal Expansion Coefficients: 10.1×10^¯6 /K (//a), 16.2 ×10^¯6 /K (//c)
• Laser Wavelength: 994-1050 nm
• Absorption Wavelength: 979 nm
• Absorption Cross Section: (π configuration at 979 nm) 2.7×10^-20 cm²

Specifications (Table 2):

• Orientation: a or c
• Standard Dopant Concentration: Yb: 1, 2, 3, 5 at.%
• Maximum Length: 50 mm
• Surface Quality (Scratch/Dig): 10/5 to MIL-PRF-13830B
• Dimensional Tolerances: Diameter: ±0.1mm, Length: ±0.5 mm
• Parallelism: 20 arc sec
• Perpendicularity: ≤15 arc min
• Coating: AR-1030/980 nm, R<0.2% @1030 nm, R<0.5% @980 nm. Other coatings available upon request.

CASTECH produces Yb:CALGO with stringent quality control and offers customization options to meet specific application requirements.