Pulse Diagnostics

APE offers a choice of solutions for ultrafast pulse measurements. Each is tailored to your type of laser system, with a wealth of innovations for greater accuracy and user simplicity.


From material processing to scientific and medical base research, ultrafast laser systems are used in many areas of their high peak intensity and extremely short pulse width. 
One relevant area of application is time resolved spectroscopy. The pulse width is a critical factor for the adjustment of these laser systems and the characterization of experiments. APE autocorrelators measure this parameter from 10 fs ... 400 ps for almost any wavelength range.

New: The pulseCheck Type II High Contrast reveals temporal information of intense pulses including their pre-pulses and pedestals.     



Watch our pulseCheck Video here.

New: The pulseCheck Type II High Contrast reveals temporal information of intense pulses including their pre-pulses and pedestals.

Pulse Measurement Perfection with the Multitalent from APE

It is good to have plenty of options at hand. Suitable for the characterization of virtually any ultrafast pulsed laser, the pulseCheck autocorrelator from APE covers the broadest possible range of wavelengths and pulse widths. This flexibility is achieved by using exchangeable Optics Sets, typically consisting of a nonlinear crystal and a dedicated detector module.

Maximum Functionality through Modular Design

APE fulfills a growing need for maximum functionality and flexibility with the modular concept on which its pulseCheck autocorrelator series is based.

From Ultrashort to Longer Pulses

The various pulseCheck configurations can be optimized accordingly to suit your individual pulse width measurement needs. Extra-long pulse durations are accessible with pulseCheck SM, which utilizes fast and highly precise stepping motor technology to measure long pulses across a larger scan range.

High Sensitivity and Low Noise with Three Types of Detectors

The three detector types address the need for low noise and enhanced sensitivity in different applications. For pulse measurement with extreme sensitivity and low pulse energy, we recommend our photomultiplier (PMT) detector. Spectrally enhanced photodiodes (PD, TPA), on the other hand, are the ideal choice for measurements requiring sensitivities of a few mW2.

Ultimate Wavelength Range

The detectors and Optics Sets available from APE cover a wide range of wavelengths, from UV at 200 nm to Mid-IR at 12 µm.

Complete Pulse Characterization with pulseCheck and FROG Option

Second Harmonic Generation FROG is the most popular spectrometer-less Frequency Resolved Optical Gating method. The pulseCheck autocorrelators by APE optionally integrate FROG, giving access to complete pulse characterization. The addition of a special nonlinear crystal module and dedicated software opens the door to complete spectral and temporal pulse characterization.

Watch our pulseLink video!

  • Exchangeable Optics Sets for broadest spectrum coverage from 200 nm to 12 µm
  • Pulse widths from as low as < 10 fs all the way up to 400 ps
  • Ultra-precise delay resolution
  • Toggle between interferometric and intensity autocorrelation
  • Wide range of sensitivity levels covered with PMT, PD, and TPA
  • Automatic phase matching
  • Gaussian, Sech2, and Lorentzian fitting routines
  • Ready to use software and USB interface
  • TCP/IP remote control with standardized command set for easy programming
  • NIST traceable calibration


Measurable Pulse Width Range

depending on Base Unit:

  < 10 fs ... 3.5 ps      < 10 fs ... 12 ps  < 50 fs ...35 ps   < 120 fs ... 60 ps
  < 120 fs ... 150 ps     < 120 fs ... 300 ps      < 120 fs ... 400 ps

Wavelength Range
200 nm - 12 µm, depends on Optics Set
Optics Sets Exchangeable
Detector (Optics Sets) PMT, PD, or TPA
Delay Resolution < 0.001 % of scan range
Delay Linearity < 1 %
Sensitivity Typically 1 ... 10-6 W2 depending on Optics Set*
Recommended Repetition Rate PD, TPA: 10 Hz and above; PMT: 250 kHz and above
Type of Measurement Mode PMT, PD : non-collinear intensity, collinear interferometric;
TPA: hybrid collinear intensity
Mode Switching Available for PMT, PD
SHG Tuning for Phase Matching PMT/PD: automatic; TPA: not applicable
Trigger Mode TTL, f < 50 kHz; pulseCheck SM < 1 kHz
Input Polarization Linear horizontal, vertical available as option
Input Beam Coupling Free-space; Option: fiber coupling FC/PC, FC/APC, SMA
Max Input Power 1 W (e.g. oscillator with a rep. rate of approx. 70 MHz) or 10 μJ (e.g. amplified system with rep. rates in the kHz range), whichever results in lower value
Input Aperture 6 mm (free-space)
Software Included; Real-time display of pulse width and central wavelength, different fitting routines
Fitting Routine Gaussian, Sech2, Lorentz
Connection USB
Remote Control Possible via TCP/IP (SCPI command set)
Calibration NIST traceable calibration certificate included

*  Measured sensitivity including Optics Set, defined as average power times peak power of the incident pulses PAV * Ppeak  


Here you can download some examples that demonstrate how to use the Standard Software Interface (using TCP/IP) with common programming languages:


This device is available directly via A·P·E and in the countries listed below via our exclusive distribution partners:

Australia: Coherent Scientific

China: Pinnacle / PulsePower

France: Optoprim

Great Britain and Ireland: Photonic Solutions

India: Laser Science

Israel: Ammo Engineering

Japan: Phototechnica

Korea: RayVis

Poland: Eurotek

Scandinavia, Baltic States: Gammadata

Singapore: AceXon

Spain, Portugal: Innova Scientific

Switzerland: Dyneos

Taiwan: SuperbIN

USA, Canada, Middle and South America: A.P.E America

  • Various Optics Sets incl. detector
  • Fiber coupling
  • Polarization rotator
  • FROG

A selection of publications mentioning the use of the pulseCheck:

Barbarin et al., Characterization of a 15 GHz integrated bulk InGaAsP passively modelocked ring laser at 1.53μm,
Optics Express, Vol. 14, Issue 21, pp. 9716-9727 (2006), Link (DOI) | Link

Chapman et al., Femtosecond pulses at 20 GHz repetition rate through spectral masking of a phase modulated signal and nonlinear pulse compression,
Optics Express, Vol. 21, Issue 5, pp. 5671-5676 (2013), Link (DOI) | Link

Finch et al., Femtosecond pulse generation in passively mode locked InAs quantum dot lasers,
Applied Physics Letters, Vol. 103, No. 13, pp. 131109ff (2013), Link (DOI) | Link

Kjellberg et al., Momentum-map-imaging photoelectron spectroscopy of fullerenes with femtosecond laser pulses,
Physical Review A, Vol. 81, Issue 2, (2010), Link (DOI) | Link

Mosley et al., Ultrashort pulse compression and delivery in a hollow-core photonic crystal fiber at 540 nm wavelength,
Optics Letters, Vol. 35, Issue 21, pp. 3589-3591 (2010), Link (DOI) | Link

Mou et al., Passively harmonic mode locked erbium doped fiber soliton laser with carbon nanotubes based saturable absorber,
Optical Materials Express, Vol. 2, Issue 6, pp. 884-890 (2012), Link (DOI) | Link

Nillon et al., Versatile dual stage tunable NOPA with pulse duration down to 17 fs and energy up to 3 μJ at 500 kHz repetition rate,
The European Conference on Lasers and Electro-Optics (2013), Link (DOI) | Link

Sun et al., A stable, wideband tunable, near transform-limited, graphene-mode-locked, ultrafast laser,
Nano Reserach, Vol. 3, Issue 9, pp. 653-660 (2010), Link (DOI) | Link

Yin et al., Relation between exciplex formation and photovoltaic properties of PPV polymer-based blends,
Solar Energy Materials and Solar Cells, Vol. 91, Issue 5, pp. 411–415 (2007), Link (DOI) | Link

Homann et al., Seeding of picosecond and femtosecond optical parametric amplifiers by weak single mode continuous lasers,
Optics Express, Vol. 21, Issue 1, pp. 730-739 (2013), Link (DOI) | Link

Liu et al., High-power wavelength-tunable photonic-crystal-fiberbased oscillator-amplifier-frequency-shifter femtosecond laser system and its applications for material microprocessing,
Laser Physics Letters, Vol. 6, Issue 1, pp. 44-48 (2009), Link (DOI) | Link

Nomura et al., Observation and analysis of structural changes in fused silica by continuous irradiation with femtosecond laser light having an energy density below the laser-induced damage threshold,
Beilstein Journal of Nanotechnology, Vol. 5, pp. 1334-40 (2014), Link (DOI) | Link

Riedel et al., Long-term stabilization of high power optical parametric chirped-pulse amplifiers,
Optics Express, Vol. 21, Issue 23, pp. 28987-28999 (2013), Link (DOI) | Link