Products
The AFT Single-Shot FROG: The Most Powerful Ultrashort-Laser-Pulse Measurement Device
An AFT single-shot FROG can measure pulses from a wide variety of sources, from the lowest-energy oscillator to the highest-intensity amplifier.
Single-shot FROGs accurately and reliably generate the pulse intensity and the phase (the spectrum and spectral phase) vs. time (vs. wavelength)
requiring no assumptions about the pulse shape. In addition, the single-shot FROG is an effective and practical diagnostic tool
for diagnosing other pulse distortions such as spatial chirp and pulse front tilt. A single-shot FROG will tell you more about your pulse than
you could ever imagine and with less effort!
Examples of the use of the AFT single-shot FROG device for detecting pulse distortions and optimizing the pulse
If you are experiencing difficulties with your laboratory experiments or manufacturing processes,
the problem could be pulse distortions such as temporal chirp, spatial chirp or pulse front tilt.
The examples below show that simple diagnostics with an ATF device will detect distortions in pulses.
Example #1
The images below illustrate the results of pulse measurements from an ultrashort fiber laser system under development at a university.
Even though the pulse is extremely complicated, an AFT single-shot FROG device (AFT-1064 LPS) precisely measures the pulse.
As substantial linear temporal chirp remains in the pulse, the peaks in the time domain are separated.
Therefore, the duration of the pulse is ~700fs.
A grating pair pulse compressor successfully compensates for linear chirp in the pulse from the same fiber laser.
The FROG device helps locate the optimized position of the grating pulse compressor.
Now, the pulse is almost a transform limited pulse, and the phase of the pulse is nearly flat; thus, the duration of the pulse is ~ 230fs.
Agreement between the measured and retrieved traces is good,
indicating that the measurement results are reliable.
Example #2
We measure a pulse from a commercial fiber laser with an amplifier system.
The image below displays a distorted trace. If the pulse generates distorted traces,
it is suffering from distortion(s). FROG traces are supposed to be symmetrical in time,
but if pulse distortion(s) are present, the trace is not symmetrical.
As a result, an active pulse control system introduces spatial chirp to the pulse, which results in distortion of the FROG trace.
A single-shot FROG device, which is inherently sensitive to pulse distortions, is a reliable diagnostic tool for ascertaining
if a pulse suffers from other distortions.
After the pulse control system is removed, the pulse no longer suffers from any distortions.
An AFT single-shot FROG device (AFT-1064 LPS) measures the pulse, the results of which appear below.
The images show that the pulse remains slightly complicated, which is typical for pulses from fiber laser systems.
It appears as if a non-linear process in the amplifier left the pulse with some minor complexities.
Agreement between the measured and retrieved traces is good,
indicating that the measurement results are reliable.
