NIST Traceable Calibration

Laboratories and manufacturers are often faced with systematically establishing an unbroken chain of calibrations to specified references. All APE autocorrelator models are calibrated to a traceable standard in accordance with NIST (U.S. National Institute of Standards and Technology) measurement traceability specifications. A printed and signed calibration certificate is provided with each pulseCheck.

UV at 200 nm to IR at 12 µm

APE provides a selection of exchangeable Optics Sets, ranging from UV at 200 nm to IR at 12 µm, for sensitive measurements across an extremely broad wavelength region.

From < 10 fs up to 400 ps

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.

FROG Option for pulseCheck

Most of the pulseCheck autocorrelators by APE optionally integrate FROG and give access to complete pulse characterization. FROG enables  pulseCheck to measure the spectral and temporal bandwidth and phase with just a few adjustments to the autocorrelator.


Three Types of Detectors: PMT, TPA, PD

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.


  • 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

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