Nd:YAG Rods

New Products

Nd:YAG Rods

Capabilities:

· Rod size: 2 - 12mm in diameter and 1 - 180mm in length;

· Nd dopant concentration : 0.6% - 1.3%;

· Polishing;

· AR-coating or/and dichroic coating;

Nd:YAG Crystal

During the last decade, Nd:YVO4 has been developed as a promising substitutes for Nd:YAG in diode-pumped lasers due to its high absorption and emission cross-sections. However, the applications of Nd:YVO4 are limited due to its poor physical-mechanical properties and growth difficulty etc. Now, we have developed the high-doped Nd:YAG (SUPER-Nd:YAG) recently. It shows high absorption cross-section and have many advantages over Nd:YVO4:

· Due to the cubic symmetry and high quality, Nd:YAG is easy to operate with TEM_oo mode

· Nd:YAG can be Q-switched with Cr4+:YAG directly

· Nd:YAG can produce blue laser with the frequency-doubling of 946nm

· Nd:YAG can be operated in a very high power laser up to kW level

The high neodymium-ion doped YAG has been grown by the novel technique-Temperature Gradient Technique (TGT). The Nd concentration can be doped up to 3%. As large as f100x80mm bulk crystals with excellent optical homogeneity, less scattering particles, low dislocation density have been obtained.

Basic Properties:

Chemical Formula	Y₃Al₅O₁₂
Crystal structure	Cubic
Lattice constant	12.01Angstrom
Melting point	1970° C
Density	4.5g/cm³
Reflective Index	1.82
Thermal Expansion Coefficient	7.8x10^-6 /K <111>
Thermal Conductivity (W/m/K)	14W/m/K, 20° C 10.5W/m/K, 100° C
Mohs hardness	8.5
Stimulated Emission Cross Section	2.8x10^-19 cm^-2
Relaxation Time of Terminal Lasing Level	30 ns
Radiative Lifetime	550 ms
Spontaneous Fluorescence	230 ms
Linewidth	0.6 nm
Loss Coefficient	0.003 cm^-1 @ 1064nm

Laser Properties:

· SUPER-Nd:YAG shows high absorption coefficients at pumping wavelengths. Therefore, a crystal short-in length (e.g.1mm) is preferred and compact microchip lasers can be constructed by using SUPER-Nd:YAG.

· Due to the broader and smoothly-varied bandwidth of absorption, it allows of less stringent requirements of temperature control.

· Almost same output have been achieved both in a (111)-cut 1mm long Nd:YAG and an a-cut 1mm long YVO4 microchip lasers with a very short (9mm) laser cavity.

Spectra Properties with Concentration:

Nd:Dopant	2.5%	2%	1.5%	1.3%	1.1%	1%
Fluorescence lifetime	160ms	180ms	200ms	210ms	220ms	240ms
Absorption coefficient	7.55cm^-1	6.57 cm^-1	5.36 cm^-1	4.66 cm^-1	3.88 cm^-1	3.55 cm^-1

Optical Quality/Grades/Nd Level
Rod Size		Standard Grade		Premium Grade		Standard [Nd]: 1.1 Atom%		Low [Nd]: 0.8 Atom%
L	D	Extinct. Ratio	Wave Error	Extinct. Ratio	Wave Error	Tolerance of [Nd] Over Rod Length		Tolerance of [Nd] Over Rod Length
mm	mm	(dB)	(waves)	(dB)	(waves)	Average [Nd]	delta [Nd]	Average [Nd]	delta [Nd]
50	3	>25	<0.19	>30	<0.13	±.08	0.06	±.07	0.05
50	4		<0.21		<0.15
50	5		<0.24		<0.16
100	4	>22	<0.28	>27	<0.18	±.08	0.13	±.06	0.09
100	5		<0.32		<0.21
100	6		<0.36		<0.23
100	6.35		<0.37		<0.24
150	6.35	>20	<0.48	>25	<0.30	±.05	0.18	±.04	0.13
150	8		<0.58		<0.35
150	9.52		<0.67		<0.40
200	8	>19	<0.71	>24	<0.42	±.02	0.23	±.02	0.17
200	9.53		<0.82		<0.49
200	10		<0.86		<0.51
Coatings
Type		Reflectivity		Damage Threshold			Damage Threshold
		(%R per Surface)		(<20nS Pulse, GW/cm^2)			(CW, kW/cm^2)
AR @1064nm		<0.15		>1.4			>25
HR @1064nm		>99.9		>1.0			>25