Passat Diode-Pumped Solid State Lasers

+1-905-695-1088 email: sales@passatltd.com

Menu
Picosecond Lasers

Air-Cooled, Picosecond DPSS Lasers

 

Laser Model Output
Wavelength
Pulse Energy (mJ) Maximum Repetition Rate (Hz) Pulse Length Pumping Cooling

COMPILER

Picosecond UV DPSSL Compiler 532 top Small

1064 nm 0.3 1000 8 ps Diode Air
532 nm 0.18 1000 7 ps Diode Air
355 nm 0.06 1000 6 ps Diode Air
266 nm 0.16 400 5 ps Diode Air
213 nm 0.04 400 4 ps Diode Air

COMPILER UPGRADE

Compiler-Upgrade-300x208

1064 nm 2 1000 8 ps Diode Air or liquid
532 nm 1 1000 7 ps Diode Air or liquid
355 nm 0.5 1000 6 ps Diode Air or liquid
1198 nm 0.3 1000 32 ps Diode Air or liquid
599 nm 0.15 1000 30 ps Diode Air or liquid
299.5 nm 0.05 1000 28 ps Diode Air or liquid

Compiler HPRR
High pulse repetition rate picosecond DPSS laser
Custom laser, please call!

1064 nm 0.15 14000 8 ps Diode Air
532 nm 0.075 14000 7 ps Diode Air
355 nm 0.035 14000 6 ps Diode Air
266 nm 0.010 14000 5 ps Diode Air

While high pulse repetition rates provide higher throughput, the high peak power of laser pulses is imperative for cutting different materials with sharper angle, thus significantly reducing material losses and increasing rate of cutting.

The high peak power is one of the most important features of Passat’s family of picosecond lasers, especially at short UV wavelengths (266 nm, 213 nm).

The chart below compares peak powers produced by commercially available DPSS picosecond lasers:

In particular, the high laser peak power is necessary for cutting transparent dielectrics (via cold ablation) with wide energy band gap such as diamond, sapphire, quartz and fused silica. This is so because, for high intensity laser beams two-photon absorption dominates over single-photon absorption, which is relatively low at wavelengths produced by most commercially available lasers. As a result, the ablation threshold drops, the ablation rate increases and the typical taper angle of cutting α becomes sharper, which increases the cutting depth. Sample cuts of different materials with different taper angle α are shown on the following page: Materials Processing

Our estimates, made for two-photon absorption, allow finding the cutting taper angle α which is determined by the following formula:

α ≈ λ/E1/2 x (ΘPD/γβτ)1/4 ,

where E is the laser pulse energy (in J), ΘPD is the energy characterizing photo-decomposition of dielectric by UV picosecond pulses (in J/cm3), β is the coefficient of two-photon absorption (in cm/W), γ is the portion of energy absorbed by the dielectric after deduction of radiative losses, while τ is the laser pulse width (in sec).

The angle α does not depend on pulse repetition rate and depends very slightly on the parameter PD/γβτ)1/4, characterizing the dielectric to be cut. But the dependence on the wavelength and pulse energy is rather strong. For example, for ΘPD = 10 kJ/cm3 , β = 4 cm/GW, γ = 0.5, τ = 5 ps, E = 100 μJ, λ = 266 nm, the angle α is equal to 6 mrad (or 0.350). Such an angle provides very low cutting losses. If anyone needs to cut a dielectric sphere half-and-half the losses will be about α/2, which for the example above corresponds to only 0.3%.

To cut material through the given thickness H, the volume of material removed will be proportional to α or ~~1/\sqrt{E}

Thus,

Even at the Same Average Power, Greater Pulse Energy Provides Faster Cutting.

DPSS lasers in the Compiler family enjoy the following technological benefits:
  1. The highest pulse energy for the laser size, especially in the UV wavelength range, which reduces material losses.
  2. High energy short picosecond pulses allow micro machining of thicker materials, such as drilling and cutting of glass, diamond, ceramics, metals, etc. up to few millimetres thick.
  3. The most compact laser head sizes (per energy unit), lightweight and lower power consumption among comparable picosecond UV lasers.
  4. Air Cooling.