Yb:CALGO Laser Crystal

来源：发布时间：2019-12-25 21

Description

Yb:CaGdAlO₄ (Yb:CALGO)- Yb doped crystals for high power and ultrashort(femtosecond) lasers

Yb-doped CaGdAlO4 crystal (Yb:CALGO) is now recognized to exhibit outstanding properties for the production of high-power and ultra-short laser pulses. It has the broad and smooth emission bandwidth to generate very short pulses (

Yb3+:CaGdAlO4 has been recently demonstrated to be very interesting for the development of diode–pumped short-pulsed modelocked lasers. Compared with Ti: Sapphire crystal（the choice for the development of ultrashort laser system producing very short and powerful pulses using the Chirped Pulse Amplification technique，Since the beginning of the 90’s）,Yb:CALGO can be directly pumped by very efficient and high power semiconductor laser.( Titanium Sapphire crystal pumped by green laser)

Parameter

Material and Specifications

Doping Concentration	1-10%
Parallelism	10〞
Perpendicularity	10ˊ
Surface Quality	20/10
Surface Flatness	<λ/10@632.8nm
Clear Aperture	>90%
Chamfer	0.1mm@45°
Thickness/Diameter Tolerance	±0.05 mm

Physical and Chemical Properties

Formula	Yb:CaGdAlO₄ (Yb:CALGO)
Crystal Structure	Tetragonal K₂NiF₄ type structure
Melting Point	1840°C
Thermal Conductivity/(W·m^-1·K^-1)	11.4(undoped) 6.3(2% Yb:CALGO) 5(5% Yb:CALGO)
Thermal Shock Resistance(W.m^-1/2)	>4.5
Thermal Expansion /(10^-6·K^-1 )	35

Optical and Spectral Properties

Emission band width* (FWHM) (nm)	80
Emission Wavelength(nm)	1018-1052
Minimum theoretical duration (fs)	14
Central emi ssion peak (nm)	1050
Absorption (usual pumping) (nm)	980
Emission cross section(10^-20 cm²)	0.8
Fluorescence lifetime (μs)	420
σ_em τ(μscm²)	336
Quantum Defect	<0.8%

Main properties of laser materials involved in the development of femtosecond lasers

Material	Emission band width(FWHM) (nm)	Minimum theoretical duration (fs)	Central emi ssion peak (nm)	Absorption (usual pumping) (nm)
Yb:YAG	9	124	1031	942
Yb:Glass	35	31	1020	975
Yb:GdCOB	44	26	1044	976
Yb:BOYS	60	18	1025	975
Yb:KGW	25	44	1023	981
Yb:KYW	24	46	1025	981
Yb:SYS	73	16	1040	979
Yb:YVO4	30	36	1008	984
Yb:CaF2	30	36	1047	980
Yb:CALGO	80	14	1050	980

Material	Emission cross section(10^-20 cm²)	Fluorescence lifetime (μs)	σ_em τ(μscm²)	Thermal conductivity (undoped)(W/m/K)
Yb:YAG	2.1	951	1997	11
Yb:Glass	0.05	1300	65	0.8
Yb:GdCOB	0.35	2600	910	2.1
Yb:BOYS	0.3	1100	330	1.8
Yb:KGW	2.8	600	1680	3.3
Yb:KYW	3	600	1800	3.3
Yb:SYS	0.44	820	361	2
Yb:YVO4	1.25	250	312	5.1
Yb:CaF2	0.25	2400	600	9.7
Yb:CALGO	0.8	420	336	11.4

Absorption and Emission Spectrum

Feature

High thermal conductivity
Large gain bandwidth
Broad and smooth emission bandwidth
Low refractiveindex-temperature gradient
Absorption band is covered by high-power InGaAs laser diodes

Application

Solid state femtosecond oscillators
Ultrafast solid-state laser

time-resolved spectroscopy, multiphoton imaging, micromachining, refractive surgery, acceleration of particles, X-rays generation, fusion, etc.
modelocked laser
BAW device
Diode–pumped short-pulsed modelocked lasers
Femtosecond lasers technology
Bicolor double-pulse regime

Yb:CALGO, it is possible to generate double pulses with different wavelengths, which is to our best knowledge the first demonstration of bicolor femtosecond double-pulse operation. Very broad spectrum has been obtained with a bandwidth greater than 30 nm . The spectrum can be fit with two Gaussians: one centered at 1040 nm with a bandwidth of 21 nm and one centred at 1057 nm with a bandwidth of 10 nm with lower amplitude (60%).

https://www.laser-crylink.com/laser-products/laser-crystal/ybcalgo/

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