Autocorrelators, invented in the 1960s, haven't changed much. Autocorrelators still yield a poor measure of an ultrashort laser pulse's width, and they say nothing at all about the pulse's phase.



Whether the pulses from your systems are a few femto-seconds or many picoseconds, whether they are near IR, IR, visible, or UV, or whether they are a high or low-rep-rate train, Advanced Femto Technology (AFT) can provide a laser pulse measurement device that best meets your needs.

Not only are our well-engineered devices compact and light, but they are also easy to align your beam—a mere ten-minute task. As the devices contain only a few optics elements, they are robust, solid, and alignment free; and they are surprisingly inexpensive.

AFT employs Frequency-Resolved-Optical-Gating (FROG) techniques. Depending on the energy of the pulse, the wavelength at the center, and the complexity of the pulse, our designs are optimal for measuring pulses. The devices quickly and accurately measure the intensity of the complete pulse and the phase vs. time and frequency without any assumption about the pulse shape.

In addition, as the AFT pulse measurement devices are capable of identifying other pulse distortions, you’ll be able to test if your pulse suffers from distortions such as spatial chirp or pulse front tilt, distortions inherent in single-shot FROGs. Therefore, if you believe you have an unusual pulse from a newly designed laser system or if you are planning to design a unique experiment with a pulse but are unsure about whether your laser systems are functioning properly, please let us help. Our custom designs provide optimal solutions for your pulses and your applications.

Single-shot FROG devices can be purchased directly from AFT!

If you haven't decided which device is the best fit for your applications. Please let us know, our experienced researcher and engineers will assist you.

Email: info@AdvancedFemtoTech.com
Tel: +1 678-488-1907 USA


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.



This tutorial introduces the light-measurement techniques, or the pulse measurement techniques.

For simplicity, the electric field will be treated as linearly polarized, so only one component of it will be considered. This is called the scalar approximation where the vector character of the pulse electric field is ignored. The electric field of the pulse can potentially be a complicated function of space and time, but we are mainly interested in the temporal features of the pulse. We also will ignore the spatial portion of the field. Therefore, Measuring a pulse means measuring the intensity and phase of the pulse. Once the intensity and phase of the pulse is known in time domain, a Fourier Transformation can give the spectral intensity (spectrum) and the spectral phase as well.



We will be more than happy to assist you with selection of the device that fits best for your applications.
Please, let us know about your pulse.

We will need approximate center wavelength, bandwidth, pulse energy, pulse duration, rep rate, and beam size.

Advanced Femto Technology

General Inquiries

General information Email: info@AdvancedFemtoTech.com

Techincal Support Email: support@AdvancedFemtoTech.com

Any question Email: tongjoo@gmail.com

Tel: +1 678-488-1907 USA: You can text me.

About Us

Advanced Femto Technology (AFT) was founded in 2013. We are specialized in single-shot Frequency-resolved optical gating (FROG) systems (SHG or TG FROGs), which is the most reliable technique for measuring femtosecond and picosecond laser pulses. The FROG measures the temporal intensity and phase OR/AND the spectral intensity and phase of the pulses. And the "single-shot" FROG is simple and robust, which has played a key role in ultrafast optical research for measuring ultrashort pulses.

Dr. Dongjoo Lee, Advanced Femto Technology's founder, has studied various FROG geometries at the Georgia Institute of Technology working on his PH. D. and had worked with Dr. Trebino who is the inventor of FROG.

Dr. Lee is the world's leading expert in ultrashort-laser-pulse measurement and has designed many kinds of FROG geometries since 2004. Additionally he has a lot of experience working on UV, Visible, IR, and Continuum measurement devices.

The AFT company is located in Atlanta, GA, USA.