Examples
Example 1
We consider a 1550 nm pulsed laser, with an average optical power of 3 W. Each pulse has a duration of 50 ps and is produced at a rate of 80 MHz. The beam diameter is 2 mm.
The command line below performs the EN207 analysis for this laser.
$ lasersafety -w 1550e-9 -p 3 -r 80e6 -t 50e-12 -d 2e-3 en207
This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
In particular, you should ALWAYS check the results provided by this code before using them for
actual laser safety.
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Laser information
Continuous: False
Wavelength: 1.55 μm
Repetition rate: 80.0 MHz
Average power: 3.0 W
Peak power: 750.0 W
Pulse duration: 50.0 ps
Pulse energy: 37.5 nJ
Beam diameter: 2.0 mm
Mode: M
Cross section area: 3.141592653589793e-06 m^2
Power density: 954929.6585513721 W/m^2
Peak power density: 238732414.63784304 W/m^2
Energy density: 0.011936620731892151 J/m^2
Corrected energy density: 2.007492316738256 J/m^2
Number of pulses in 10s: 800000000.0
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EN207 analysis
1550.0 nm D LB3
1550.0 nm M LB1
The code displays all the parameters of the laser, included the one that were computed. It also provides the result of the analysis, requiring a scale number of LB3 for the D mode and no protection (scale number of -2) for the M mode.
Now let us suppose, that in the consider setup, the second harmonic might be generated, using a Second Harmonic Generation (SHG) stage. This generates light at a wavelength of 775 nm. Assuming that this process does not change the parameter of the beam (same pulse duration, same beam diameter, same repetition rate), and assuming a maximal efficiency of 100 % (each 2 photon for the initial beam produce 1 output photon in the output beam, or said otherwise the energy is fully conserved), meaning that the output power of the beam remains the same.
In this case, the script must be run a second time:
$ lasersafety -w 775e-9 -p 3 -r 80e6 -t 50e-12 -d 2e-3 en207
This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
In particular, you should ALWAYS check the results provided by this code before using them for
actual laser safety.
----------------------------------------
Laser information
Continuous: False
Wavelength: 775.0 nm
Repetition rate: 80.0 MHz
Average power: 3.0 W
Peak power: 750.0 W
Pulse duration: 50.0 ps
Pulse energy: 37.5 nJ
Beam diameter: 2.0 mm
Mode: M
Cross section area: 3.141592653589793e-06 m^2
Power density: 954929.6585513721 W/m^2
Peak power density: 238732414.63784304 W/m^2
Energy density: 0.011936620731892151 J/m^2
Corrected energy density: 2.007492316738256 J/m^2
Number of pulses in 10s: 800000000.0
----------------------------------------
EN207 analysis
775.0 nm D LB5
775.0 nm M LB5
At the end the required eyewear must have : 1550 D LB3 775 D LB5 + M LB5
Example 2
We consider a 10 Watt continuous wave (CW) laser, with a single wavelength of 1064 nm and a beam diameter of 4 mm.
The command below performs the EN207 analysis for this laser.
$ lasersafety -w 1064e-9 -p 10 -r 0 -d 4e-3 en207
This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
In particular, you should ALWAYS check the results provided by this code before using them for
actual laser safety.
----------------------------------------
Laser information
Continuous: True
Wavelength: 1.064 μm
Repetition rate: 0Hz
Average power: 10.0 W
Peak power: 0W
Pulse duration: 0s
Pulse energy: 0J
Beam diameter: 4.0 mm
Mode: D
Cross section area: 1.2566370614359172e-05 m^2
Power density: 795774.7154594768 W/m^2
Peak power density: 0.0 W/m^2
Energy density: 0.0 J/m^2
Corrected energy density: 0.0 J/m^2
Number of pulses in 10s: 0.0
----------------------------------------
EN207 analysis
1064.0 nm D LB5
Note that the repetition rate was set to 0 to indicate that the laser is continuous.
This requires a scale number of LB5 for D at 1064 nm.
Example 3
We consider a laser that produces a CW power of 5 W at 532 nm (green) with a beam diameter of 2 mm, and we want to consider alignment glasses for this laser.
The command below performs the EN208 analysis for this laser.
$ lasersafety -w 532e-9 -p 5 -r 0 -d 2e-3 en208
This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
In particular, you should ALWAYS check the results provided by this code before using them for
actual laser safety.
----------------------------------------
Laser information
Continuous: True
Wavelength: 532.0 nm
Repetition rate: 0Hz
Average power: 5.0 W
Peak power: 0W
Pulse duration: 0s
Pulse energy: 0J
Beam diameter: 2.0 mm
Mode: D
Cross section area: 3.141592653589793e-06 m^2
Power density: 1591549.4309189536 W/m^2
Peak power density: 0.0 W/m^2
Energy density: 0.0 J/m^2
Corrected energy density: 0.0 J/m^2
Number of pulses in 10s: 0.0
----------------------------------------
EN208 analysis
532.0 nm RB4
This requires a RB4 at 525 nm.
Example 4
We need to find the full attenuation laser protective eyewear for a pulsed laser that produces 4.5 µJ per pulse at 800 nm with a pulse repetition frequency of 200 kHz. The duration of each pulse is 200 fs. The accessible beam diameter is 3 mm.
$ lasersafety -w 800e-9 -r 200e3 -t 200e-12 -e 4.5e-6 -d 3e-3 en207
This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
In particular, you should ALWAYS check the results provided by this code before using them for
actual laser safety.
----------------------------------------
Laser information
Continuous: False
Wavelength: 800.0 nm
Repetition rate: 200.0 kHz
Average power: 900.0 mW
Peak power: 22.5 kW
Pulse duration: 200.0 ps
Pulse energy: 4.5 μJ
Beam diameter: 3.0 mm
Mode: M
Cross section area: 7.068583470577034e-06 m^2
Power density: 127323.95447351628 W/m^2
Peak power density: 3183098861.837907 W/m^2
Energy density: 0.6366197723675814 J/m^2
Corrected energy density: 23.940742850854825 J/m^2
Number of pulses in 10s: 2000000.0
----------------------------------------
EN207 analysis
800.0 nm D LB5
800.0 nm M LB6
This requires 800 D LB5 + M LB6