Water Cooled DPSS Laser Gain Modules

For QCW DPSSL gain module gain distribution, pumping efficiency and life time are three most important indices. The gain distribution has two effects on beam quality. On one hand the energy density distribution sets the distribution of the gain and the non-uniform gain distribution result in changes of intensity distribution in near field; On the other hand thermal effect in the gain medium cannot be ignored at high frequency. Uniform energy density means uniform heat density and the wave-front distortion is parabolic, which can be regarded as a lens and compensated easily. While non-uniform energy density results in high order distortion which is hard compensated for and reduces the focusing ability of the beam. In multi-pass amplifier these effects come worse.

Based on several-year efforts on DPSSL gain module and our VCSEL technology, Geola can provide DPSSL gain module with uniform gain distribution, high pumping efficiency and a long life time. We have two types of gain modules, namely water-cooled cylindrical gain module and all solid state gain modules. We also provide customized gain module on request.

VCSEL array VS traditional Laser Bar

Parameters VCSEL LD Bar VCSEL Advantages
EO efficiency 40%–50% 50%–60% Keep improving..
Spectrum width ~1nm ~3nm Narrow spectrum
Wavelength-temperature coefficient 0.07nm/K 0.3nm/K Insensitive to temperature
Long time wavelength shift No Yes Stable over time
Optical damage threshold No COD Terrible COD High damage threshold
Direct heat conductive area Large Small Easy for heat remove
Heat stress during pulsing Low High Very good at pulsed operation
Max operation temperature >85℃ 30~45℃ High temperature?operation
Current inrush sensitivity Insensitive Very Sensitive Very robust to driver
Voltage-current relation Linear Nonlinear Simple driver design
Pulsed life time (200us) >20G?shots 1-2G shots 10 times longer life time
Power degradation Near- Linear Nonlinear Life time can be expected
Manufacture cost Low High Very low cost

Water-cooled cylindrical gain module

Item Parameter
Repetition rate 1~1000Hz
Electrical Pump power 1~27kW
Pulse width 200~300μs
Rod diameter 2~15mm
Cooling Water cooling
Wavelength 806nm?± 3nm
Linewidth (FWHM) 4 nm
Size Can be customized


Geola gain module

SLD type explanation

Typical VCSEL-pumped gain modules

Gain?Model, № Nd:YAG crystal, mm SLD?chips, pcs Electrical Pump Power, W
Optical Pump Energy (200μs,100Hz), mJ
SLD-3×3-3 ?3 9 1350 >108
SLD-3×5-3 ?3 15 2250 >180
SLD-3×7-3 ?3 21 3150 >252
SLD-3×6-4 ?4 18 2700 >216
SLD-3×10-4 ?4 30 4500 >360
SLD-5×7-6 ?6 35 5250 >420
SLD-5×9-6 ?6 45 6750 >540
SLD-5×10-6 ?6 50 7500 >600
SLD-5×15-6 ?6 75 11250 >900
SLD-5×7-8 ?8 35 5250 >420
SLD-5×9-8 ?8 45 6750 >540
SLD-5×13-8 ?8 65 9750 >780
SLD-7X6-10 ?10 42 6300 >504
SLD-7×11-10 ?10 77 11550 >924
SLD-7×15-10 ?10 105 15750 >1260
SLD-7×10-12 ?12 70 10500 >840
SLD-7×15-12 ?12 105 15750 >1260
SLD-9×10-12 ?12 90 13500 >1080
SLD-9×15-12 ?12 135 20250 >1620
SLD-9X10-15 ?15 90 13500 >1080
SLD-10×14-15 ?15 140 21000 >1680


Custom made gain modules are available


Module size, pump power, cooling fitting type and location and mechanical parts could be customized.