EKSMA - Nonlinear and Laser Crystals

Nd-doped Potassium Gadolinium Tungstate Single Crystals - Nd:KGW

Nd:KGW crystals are low lasing threshold, highly efficient laser material exceptionally suitable for laser rangefinding applications.

The efficiency of Nd:KGW lasers is 3–5 times higher than the one of Nd:YAG lasers. Nd:KGW laser medium is one of the best choices ensuring effective laser generation at low pump energies (0.5–1 J). These crystals supplied by EKSMA Co. feature high optical quality and great value of bulk strength for laser radiation.

Existing technology allows to obtain single crystals of mass up to 3 kg. This ensures reliable and high yield fabrication of round elements of diameter up to 12 mm and length up to 120 mm.

MATERIAL PHYSICAL AND LASER PROPERTIES

Chemical formula

KGd(WO₄):Nd

Lattice constants

a = 4.748 Å, b = 10 Å, c = 12.957 Å

Optical orientation

n_g = b, n_pc = 20 deg

Angle between optical axis

86.5 angular grad

Density

7.27 g/cm³

Mohs hardness

5

Thermal conductivity
2.8 W/(m×grad) [100]
2.2 W/(m×grad) [010]
3.5 W/(m×grad) [001]

Thermal expansion
4×10^-6 grad^-1 [100]
3.6×10^-6 grad^-1 [010]
8.5×10^-6 grad^-1 [001]

Phase transition

1005°C

Melting point

1075°C

Transmission range

0.35-5.5 µm

Refractive indice

n_g = 2.033 @ 1.067 µm
n_p = 1.937 @ 1.067 µm
n_m = 1.986 @ 1.067 µm

Transition

⁴F_3/2 -> ⁴I_11/2

Laser wavelength

1.0672 µm

Fluorescence lifetime

120 ms

Fluorescence width

24 cm^-1

Emission cross-section

4.3×10^-19 cm^-2

Emission cross-section

8.5×10^-4 nm, K^-1

TANDARD PRODUCT SPECIFICATIONS

Orientation	[010] ±30 min
Dopant concentration	2-10 at %
Diameter tolerance	+0.0/-0.1 mm
Length tolerance	+1.0/-0.0 mm
Chamfer	45(±10) deg × 0.2(±0.1) mm
Flatness	λ/10 @ 633 nm
Parallelism	better than 30 arcsec
Perpendicularity	better than 15 arcmin
Surface finishing	10/5 scratch/dig
Absorption losses	< 0.005 cm^-1

Yb:KGW and Yb:KYW Crystals

Yb-Doped Potassium Gadolinium Tungstate (Yb:KGd(WO₄)₂) and Yb-doped Potassium Itrium Tungstate (Yb:KY(WO₄)₂) single crystals are the new laser crystals for diode or laser pumped solid-state laser applications.

Applications:

Yb:KGW and Yb:KYW thin (100–150 µm) crystals are used as lasing materials to generate ultrashort (< 100 fs) high power (> 22 W) pulses. Standard pumping at 981 nm, output: 1023–1060 nm
Yb:KGW and Yb:KYW can be used as ultrashort pulses amplifiers
Yb:KGW and Yb:KYW are one of the best materials for high power thin disk lasers.

Features:

High absorption coefficient at 981 nm
High stimulated emission cross section
Low laser threshold
Extremely low quantum defect λ_pump/ λ_se
Broad polarized output at 1023–1060 nm
High slope efficiency with diode pumping (~ 60%)
High Yb doping concentration.

Custom manufacturing capabilities:

Various shapes (slabs, rods, cubes)
Different dopant levels
Diversified coatings
Attractive prices of introductory quantities to OEMs.

Absorption and emission spectra of Yb(5%):KYW

Absorption and emission spectra of Yb(5%):KYW

Titanium Doped Sapphire - Ti:Sapphire

Al₂O₃:Ti³⁺ – titanium-doped sapphire crystals combine supreme physical and optical properties with broadest lasing range.

It’s indefinitely long stability and useful lifetime added to the lasing over entire band of 660–1050 nm challenge “dirty” dyes in variety of applications. Medical laser systems, lidars, laser spectroscopy, direct femtosecond pulse generation by Kerr-type mode-locking – there are few of existing and potential applications.

The absorption band of Ti:Sapphire centered at 490 nm makes it suitable for variety of laser pump sources – argon ion, frequency doubled Nd:YAG and YLF, copper vapour lasers. Because of 3.2 ms fluorescence lifetime Ti:Sapphire crystals can be effectively pumped by short pulse flashlamps in powerful laser systems.

Czochralski grown Ti:Sapphire crystals of highest optical quality, figure of merit and different doping levels are routinely available from EKSMA.

STANDARD PRODUCT SPECIFICATIONS

Orientation	Optical axis C normal to rod axis
Ti₂O₃ concentration	0.03-0.25 wt %
Figure of Merit	> 200 (> 300 available on special requests)
Size	up to 20 mm dia and up to 130 mm length
End configurations	flat/flat or Brewster/Brewster
Flatness	λ/10 @ 633 nm
Parallelism	10 arcsec
Surface finishing	10/5 scratch/dig
Wavefront distortion	λ/4 inch

MATERIAL PHYSICAL AND LASER PROPERTIES

Chemical formula	Ti³⁺:Al₂O₃
Crystal structure	Hexagonal
Lattice constants	a = 4.748, c = 12.957
Density	3.98 g/cm³
Mohs hardness	9
Thermal conductivity	0.11 cal (°C x sec x cm)
Specific heat	0.10 cal/g
Melting point	2050 °C
Laser action	4-Level Vibronic
Fluorescence lifetime	3.2 msec (T = 300 K)
Tuning range	660-1050 nm
Absorption range	400-600 nm
Emission peak	795 nm
Absorption peak	488 nm
Refractive index	1.76 @ 800 nm