YCOB crystal is one of the most widely used nonlinear optical crystals. Its nonlinear optical coefficient is equivalent to that of BBO crystal and LBO crystal. The effective frequency multiplication coefficients of the second and third order reach 2, 8 and 1, 4 times of KDP respectively.The YCOB crystal has the following advantages : large aperture, high damage intensity in femtosecond regime,about2000-2500GW/cm2 wide allowable Angle range and allowable temperature range,small dispersion Angle, shorter growth period by Cz method.At the same time, it has stable physical and chemical properties (non-deliquescent) and good machining properties. Therefore, it is considered to have good application prospects of blue-green light and UV band optical frequency multiplier crystal.
YCOB (YCa4O(BO3)3, Yttrium Calcium Oxyborate)—Nonlinear crystal considered to have good prospects of UV band optical frequency multiplier
One of the latest technical achievements connected with YCOB is the generation of 2.35-W CW green output (λ = 532 nm) in a 1.2-cm-long crystal (θ = 64.5◦, φ =35.5◦) via inter cavity SHG of a diode-array end-pumped Nd:YVO4 laser (P = 5.6W). Another similar application is THG of NdYVO4 laser radiation. Using the KTP crystal for frequency doubling and a 1.1-cm-longYCOB crystal (θ = 106◦, φ =77.2◦), the authors managed to obtain 124mW of quasi-CW light (pulse repetition frequency 20 kHz) at 355 nm.
|Crystal Structure||Monoclinic, Point group m|
|Lattice Parameter||a=8.0770 Å, b=16.0194 Å , c=3.5308 Å , β=101.167º, Z=2|
|Melting Point||About 1510ºC|
|Thermal Conductivity||2.6 W/m/K (||X), 2.33 W/m/K (||Y), 3.1 W/m/K (||Z)|
|1.1||18.4||along Y axis, E||Z|
|The blue line is the spectrum intensity after SHG. The red line is the measured phase by Wizzler||The blue line is the pulse FTL shape after SHG. The red line is the measured temporal shape by Wizzler.|
|OPA spectra obtained by ﬁrst stage (solid black line) based on BBO crystal and second stage (solid red line) based on YCOB crystal.||X-ray rocking curve of YCOB wafer|
|Transmission Spectrum of YCOB Crystal|
Orientation: XZ plane,Type Ⅰ;